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chich2
10-16-2006, 08:15 AM
Firstly, I'd like to say hello to everyone on this awesome forum.

Well here is the start of my CNC conversion of a Hafco Metal Master HM-52 Horozontal and Verticle Knee mill. It is a Tiawaneese machine which I purchased from the importer here in Australia. The machine itself is very similar in design to a Bridgeport machine only heaps cheaper. I have already done many manual jobs with it so far and it has passed every test with flying colours. Here is a photo of the HM-52. It cannot be seen in the photo but the HM-52 has 2 drive motors, one for each INT30 spindle, both are belt drive, automatic feed on the X axis, coolant pump, 1000mm X 240mm Table, 600mm Longitudinal Travel, 180mm Tranverse travel, vert spindle to table is 375mm, spindle stroke 125mm, spindle speeds from 90 to 2400rpm running mains power at 1.5kW. Machine stands 2060mm tall and weighs 800kg.
All slide ways are dove tail's including the ram. The Vertical spindle has a fine feed and can tilt side to side and the ram can swing a full rotation...... oh and the table can also swivel.
For the price of this thing it is amazing just how many configurations it can handle.
More posts to come........

chich2
10-16-2006, 08:42 AM
My original plans were to purchase a ready built second hand CNC mill but when I came across the HM-52 I decided to build one myself. This post is a update of how my progress is going. I will start with a description of the attached photo's. The first one is the day I picked my mill up. It was bolted to a wooden pallet, compleatly enclosed in cling wrap and drowned in storage preservative. Total weight including tooling and extras came in at 1.1Ton.
Here are my servo motors. I purchased them from "babinda01" here on the Zone. He tells me they are wheel chair motors. each motor is new and in excellent condition. They are 24volt with a max current rating of 20amps. I hope to use them to automate X,Y,Z and my indexing head "A". If you look closely at the motor on the left you will notice I have faced the writing off the end plate and also machined a shoulder and added an o-ring. The flat faced surface is where I will mount my optical encoders. I have modified the black plastic cover to go onto the oposite end of the motor and machined it to push up tight onto the o-ring. This should keep my encoders clean.
Next photo is of my optical shaft encoders. I purchased them from US Digital and had them at my doorstep in Australia in 6 days. Very happy with that. The last photo is one of my drive pulleys. They are XL series belts and pulleys with a 4:1 reduction.

chich2
10-16-2006, 09:49 AM
Today I finished making the components to eliminate backlash in the nut on my X axis leadscrew. I started off by removing the power feed unit and had a bit of a look at what was there. I have done a lot of reaserch on ball screws and the thought of the cost of fitting out 3 axis's with them I gladly opted to go the old (and cheap) way out to eliminate the backlash with 2 preloaded nuts. I left the original nut securely attached to the machine and started making my own. The original nut is in great condition and secured very well. All I had to do was make another nut and use it to pull away from the original nut.
The first photo has the X axis power feed unit removed and the material sitting on the table to make the adjuster.
The next photo is milling out the mount.
Photo 3 is the finished mount.
In the next 2 photo's I had to mill a small flat into the cross slide casting of the machine to fit the anti backlash nut. To do this I removed the X axis lead screw, removed the X axis limit stops and pulled the table back out of the way exposing the slide ways below. I then pivoted the ram to 20deg and raised the knee all the way up and took the vert spindle down to meet it. By screwing the ram and the Y axis I easily milled the flat.
Using my lathe, I machined a 4mm pitch nut from brass and attached it to the mounting plate.
The last photo is of the monting plate held into position. Tomorrow I will mark out the holes on the machine and drill and tap them. Then I have to bolt it all on, adjust it up and then start on the bearing mount to eliminate the axial movement (backlash) in the hand wheel assembly.

Chich

jkujawa
10-16-2006, 08:28 PM
Wow! This is a great post! I am very eager to watch your progress. I think your machine is almost identical to one which I am considering. It is also an Asian machine (not sure if it is Chinese or Taiwanese) and sold through Grizzly: http://www.grizzly.com/products/G3616 and Shop Fox: http://www.woodstockint.com/Products/M1008 I did several searches and could not find any descriptions of CNC conversions on this site, so I am very interested in your progress. Please keep the detailed photos and excellent descriptions coming!

chich2
10-17-2006, 12:29 AM
Thanks for your kind reply jkujawa. Yes the 2 machines in your post are very similar to my HM-52. The configuration of this type of mill is always stretching ones imagination into different setup positions. If you have time to look at http://www.cnczone.com/forums/showthread.php?t=23872&page=2 I have added some photo's of some toothed pulleys I have milled on my HM-52. (You will have to go through the pages)

Today I drilled and taped M10x1.5 into the machine for the mounting plate screws. Then the brass nut I made was screwed onto the shaft and then the mounting plate bolted into position. Next step was to adjust it all up and give it a go.

The travel was quite stiff and I noticed the original power feed unit had trouble down the -X end more than the +X end. I set the power feed unit to rapid and ran the table backwards and forwards many times keeping fresh hyraulic oil up to the lead screw and nut to keep it lubricated and also to flush away any contaminants created while the new nut was run into the lead screw. I still have a hand wheel on the screw so I was able to turn it by hand to take some of the load off the puwer feed unit. I now have X axis running fairly smooth BUT NOW with only 0.03mm of backlash......... Sweet!!!!!! I will continue to run it backwards and forward and then probably have to make a very small adjustment in some time. I believe I can very easly reduce the 0.03mm down even more.

Greolt
10-17-2006, 01:17 AM
Chich2 I am following your thread with interest. I have a HM-50

Keen to see how you tackle the Z and with what results.

Thanks for taking the time to share. :)

Hope your getting more rain up there than we are.

chich2
10-17-2006, 03:39 AM
Greolt,
Yes it is raining as I write this reply. Up to 7 meters of annual rainfall means that it never stops raining. That together with cyclone Lary that hit us this year means there is plenty of time for CNC conversions and I got a good computer out of the dump to run the machine with.....:p

I havent decided yet if I am going mount the motors on X and Y or keep on the back lash quest and eliminate it from Y. Time to hit the drawing board.

Oh! Did I mention it rains a lot here? :)

chich2
10-17-2006, 04:10 AM
My brother inlaw has been so kind to lend me the corner of his shed to set up a small Hobby machine shop. The floor of the machine shop is 3 sheets of 1.6mm gal steel sheet welded together with 100mm edge bent up the entire way round. This is my chip tray and is fully sealed up with the mig welder to prevent collant or chips going every where. I also put up 2 curtain rails with cheap plastic curtain around the shop to prevent spraying anything all over the shed. Around the back wall is lino or vynal floor covering hung up to again prevent making a mess. (Cool patern too) You can see my mill and also my lathe which is a Hafco Metal Master AL-340A. I got some paint colour matched to my mill and painted a 4X2 inch timber kick rail around the gal tray and also the top of the work bench.

Special thanks goes out to Mango who transported my Mill home in his ute, Curly who unloaded and positioned my mill with his backhoe, Russell aka epineh here at the zone for putting up my lighting (it's amazing what you can make when you can SEE!) Mum..... (Because you should always thank ya mum). Babinda01 here at the zone for the Tech CNC stuff and My brother inlaw for all the floor space I stole in his Shed! Cheers Rob!!!

epineh
10-17-2006, 04:22 AM
Nice work on your mill so far man, and I gotta say that you have some REALLY nice lighting installed, are those tri-phos tubes in the fluoro's by any chance ?

Whoever put those in for you must be really talented (and probably good looking as well :stickpoke )

Russell.

jkujawa
10-17-2006, 08:41 AM
Coming along very nicely! Nice backlash nut assy. Looks like you have plenty of room to adjust to keep it tight. When you finish I will be interested to know the total time and $ spent.

Keep them coming!

Thanks!!

epineh
10-20-2006, 02:26 AM
Hey Chich, you might like to know that your power supply for your servo's is sitting on your bench, you now have a supply that can deliver 90 amps @ 24Vdc for a duty cycle of one hour, I though you might like some redundancy with that so you have two, so 90 amps for two hours or 180 amps for one hour, though realistically you won't need that much, so your duty cycle will probably whatever you want, PM me if you want any more info.

Oh yeah and ZERO ripple, I was talking to Andrew and he said you should aim for as little ripple as possible, so I thought that none was pretty good :D

Russell.

Adobe Machine
10-20-2006, 11:37 PM
Nice, stout looking machine..and some good machining too..keep up the pics and info on your conversion. How are the ways and gibbs oiled on your machine ? What software and servo amps are you using ?
Thanks from a lot of us..

Adobe (old as dirt )

chich2
10-21-2006, 01:08 AM
Russ,
Your a Legend!!!!!!!!!!!!!!! Well done mate!!!!!! Thank you verrrrrrrrry much! I owe you one........ Make that 2! I defintely think that will be the way to go for all the power supply needs.

Adobe Machine,
The Hafco HM-52 has grooves in the top of the load bearing surfaces of the dovetails. The sides of the dovetails (angled section) does not. The oil grooves are fed by a spring loaded ball bearing oil point that the operator injects oil through with an oil can. The oil grooves transport and distribute the oil to the entire length of the slide. Halfway allong, the groove breaks out to the gibb supplying it with oil.
Software will probably be Mach3 from ARTSOFT and my servo drivers will be custom units from Babinda01 here at cnc zone.

chich2
10-21-2006, 01:45 AM
I decided to stay on the anti backlash quest to take all the slop out of the lead screw nuts. After that I will make the bearing housings to eliminate any play from my lead screw thrust. Then my motor mounts.

I wanted to take out the Y axis lead screw and nut to see how much room I had to play with and also check to see how the nut is mounted. I have removed the Y axis hand wheel, bearing mount and lead screw. To remove the lead nut I removed the gibb from the table and removed the table. It was very heavy but with some help from my brother inlaw we got it on the ground without too much trouble. Next I released the bolts on the table pivot and spun it around to remove the "T" slot blots. After that was to tap the center pivot pin out that the mount pivots on and then lift the mount off. After doing that I found the Y axis nut securing screw and removed it. A bit of a tap with a drift and out came the Y axis nut.

The design for the Y axis will be different to the X axis nut I made as the Y axis nut is easly accsessed from under the knee. I will make 2 new nuts by machining 2 pieces of brass so that they can be bolted together. I will then bolt them together and machine the thread right through both of them. One will have the same mounting to the milling machine and the other one will be able to be shimmed away from the mounted nut and bolted hard against the mounted nut.

P.S. Adobe Machine,
You can see the oil grooves on the slides in some of the photo's.

Chich

epineh
10-21-2006, 06:31 AM
PM sent with all the details, I think you will like what I have created mwahaha

Russell.

chich2
10-23-2006, 02:25 AM
Good one Russ!!!! Once again you hve come up with the Tech-o gear!!!! I don't mind at all...... Sure is easy to see with all this LIGHT!!!!!

Chich

epineh
10-23-2006, 07:05 AM
No probs... have you finished yet ?

Russell.

leeroy
10-23-2006, 08:21 AM
G'day Chinch

I also bought a HM 50 (similar to hm52) machine about 2 years ago and after some modification i am very happy with it.
I have been trolling the web for info on conversion to cnc for a while and bugger me if here you are! :-)
I too was a little put off (read gobsmacked) by the cost of ball screws to fit out this machine, (around $3000), so i realy like your idea for just loading up the nut with another one, simple but effective.
I am realy interested in your plans for tackling the z axis as i have been sitting here pondering this my self. That knee and table are mighty heavy and i would think you will need a good reduction box to drive from a small dc motor. Allthough the weight will be an advantage in that you might not need to fit a preload nut on the z axis..
I had thoughts of utilising the quill feed allthough there is a lot of slop in the rack and pinion and the worm that will require total rebuild in this area. There is also some slop and loss of rigidity as the quill is extedned towards the lower limit of travel.

Again i would love to hear your thoughts on this..

Cheers
Leeroy

chich2
10-24-2006, 02:31 AM
Leeroy,
Thanks for the post. Yes the Z-axis is a point of much discussion. I whould have liked to convert the knee to CNC on my machine as the HM-52 also has the horozontal spindle. This whould have allowed me full use of my horozontal spindle and have X as the table left and right, Y whould have been up and down on the knee, and Z whould have been what Y currently is now on the cross slide. CNC gear cutting whould have then been an easy option once I CNC'd my indexing head with the cutter held on the horozontal arbour. (Pictures can be seen of this when I manually cut some timing pulleys). http://www.cnczone.com/forums/showthread.php?t=23872&page=2

With motor controll set up this way then also lets you use the verticle spindle, which is the one you would use. X whold be the table left and right, Y would be the cross slide and Z would be the knee up and down.

It would be very easy to have 2 different setups saved in your software so that when you start your controll computer you simply select the mode you want to machine in for the task and the computer runs the mill in that configuration.

The million dollar question though, is often argued about wether you automate the verticle quill - or the knee. I have seen a lot of people do the knee and on the other hand a lot do the spindle. Both of which work great.
Generally the people who CNC the knee have to put a huge motor drive on it to handle the weight and expensive drive electronics to achieve their result. Some add a Gas strutt, (like on the boot or bonnet of some cars - but bigger) to help oppose the weight of the knee. There is also the option of rigging up a Counterweight arrangement to help lift the knee. I'm sure there are also more options than these, and they all seem to work. There are always little problems with each of them like for instance the cost of a huge drive. The Gas strutt set up is fine untill you go and place a job on your machine and all of a sudden the the knee weighs much more and the drive works hard again to lift and lower it. Steel is heavy so even placing or removing a vice is going to make a difference. The counterweight option caters for the change in weight of the job as you can weigh the job before you put it on the machine and simply add and remove from the counter weight. Works well! The only change that will be encountered is the addition of mass to the load. In this I mean that excelleration and decelleration of the knee will change because you are now shifting almost doubble the total mass of the knee and job. The knee will be sluggy and rappid moves may suffer due to the drive ramping up and down.

I am going to CNC the quill for now. It is a job that is easily in my reach and I have done several sketches of different configurations to come up with the one I'm going to use. The great thing about the quill is that it hardly changes in weight. The only change is a different tool or cutter. This is a big win for me as I can run all the same motors, drive pulleys, belts and control gear for all 4 axis of my machine and also cut down on spares needed to keep the machine running.

My Quill like yours also has a lot of slop as it extends down out of the head. The rack and pinion is un adjustable and has the backlash I would expect from a rack and pinion of this type. I will be adding to this thread as I convert the quill as I am not happy with the amount of runout the quill has when it is extended out a long way. I have already purchased a lenth of Brass 100mm OD and 75mm ID to bush the quill and will be doing that once I have my X and Y axis complete.

Remember there is no right or wrong way of doing the Z axis so please be inventfull and see what suits your set up.
Excluding you Leeroy I dont want this thread to turn into a Z axis debate.

I hope this has been of some help.

Thanks,
Chich.................not Chinch :rainfro:

leeroy
10-24-2006, 07:52 AM
Chich

Thanks for taking the time to post such a detailed reply. Time on the computer = less time in the workshop! :-)
I got a little excited today and dismantled the spindle quill and downfeed mechanisim to see just what i was up against.. Everything is as i expected except that the bore for the quill is not continuous, but consists of two bands or bearing surfaces about 35mm long and about 130mm apart. The hollow section in between allows the pinion to engauge the rack.
See attached photo.

There is about 0.05mm clearence on the quill (90.00 bore and 89.95 quill).
This will have to be bored and rebushed with a continuous Bronze bush and then make new cutouts for the pinion and clamp. With carefull boring and honing, should be able to reduce the clearence to 0.005-0.01mm.
The other more expencive option is to have the quill hard chrome metal sprayed and reground to size. Allthough i think the heat from this process would probably warp the quill. But i think i will have the quill reground no mater which method i choose as it's a pretty rough grind job.

Looking at the rack and pinion i don't think this could be made to work well enough for a z axis drive. The teeth don't realy mesh very well and it's got an awfull lumpy/jerky feel when the pinion is roled over the rack by hand. Perhaps this could be bedded in a little better with some grinding paste but i'm not hopefull..:(
I think a better option for driving the quill is to mill a new 20mm slot in the front of the housing into the quill bore, drill and tap a matching spigot into the quill and make something similar to the bridgport quill conversion described in the bridgeport forum here. You would have to leave around 25mm of meat at the top and botom of the slot and this would limit the z axis to arround 80mm total travel(130-2*25). This should be enough for most jobs that i would do..

I think i will follow your leed and make start on the x and y axis and do some more searching and head scratching on the z axis..

As i'm trying to keep the cost as low as posable i'm leaning towards stepper motors rather than servo drives. Also because i can build the stepper driver electronics my self.
But i would be interested to know how much you payed for your servo drives?


Cheers

Leeroy

chich2
10-25-2006, 01:31 PM
Leeroy,
You and I have had the same toughts. I had also thought of hard chroming the quill up to size but this was going to cost me $890 bucks so that wasn't to be an option. You can very easily purchase ready to go Honed hollow steel tube for making hydraulic cylinders. I was thinging of sleeving the head with a steel bush of this material but that is no good as steel on steel will have bad wearing prpoerties. One option is to bush it with brass so for $150 Inc tax I purchased a piece as described in my previous post. When it comes time to bush the quill I will skimm the OD of the bronz to size, remove the entire head from the mill and bolt it to the cross slide of my lathe, right through it I will place a 70mm piece of high tensile bar between centers as a long solid boring bar. This boaring bar will hold a cutting tool. Using the lathe to spin the boring bar horizontaly I will bore out the inside of the head to siut the OD of the bronz Bush. I will then insert the bush into the head with a chemical lock like "loctite" without moving the head on the cross slide. After that I will bore the inside of the bush to suit the quill. With the length of bronz I have it should pick up the bottom web the mid web and also the top web where the pulley is mounted. After that I will mount the head to the table of my mill and use the horizontal axis to bore out the pinion and lock holes. I would have normally done all of this job in the mill but the Y axis doesn't have enough travel.

A very easy solution to this entire problem provided your quill is straight, smooth and parallel is to use a liquid filler and simply fill up the inside if the head with putty to suit the quill. An excellent product for this is MOGLICE. Examples of it can be seen at http://www.moglice.com/ If you take a look in their "Application Examples" and take a look at "Ingersoll Quill Bore + Elevating Nuts" you will see what I mean. All you have to do is clean everything up, plug up your holes, spray the quill with release agent and put it in the head, inject the moglice in and hey presto..... a perfect fit.

I have no idea what the product costs But I do know someone who has used it many times before and swears by it's accuracy. It is a very attractive solution. If you use a filler or bush it you will retain full travel in the quill.


For your question on the Z axis drive mechanism I am going to use will consist of the following;
I will bolt the head to my table with the quill center axis straight to and square to the column of the mill. I will use the horizontal spindle to mill the side of the head flat where the stop start switch is on the HM-52. This flat surface will be parallel and square to the quill. (I will later include the stop start switch to a movable boom) To the side of the head I will then mount my servo motor and drive mechanism. I will make a large solid steel clamp that will firmly hold the fat part of the quill. It will be a tear drop shape when viewed from the top. The pointy end of the teardrop will have a tube connected to it which contains the lead nut at the top. The motor mount which is bolted tight to the head will also hold 2 preloaded annular contact bearings firmly holding the Z axis lead screw in place. The way it will work is the motor and lead screw will stay stationry to the head and as the screw turns, the nut (anti backlash once again) in the tube will push the tube up and down. The tube is connected to the large quill clamp so therefore the quill will go up and down. All the thrust will be on the 2 annular contact bearings and the lead nuts......... Simple! :confused:

I have designed Z this way beacause if I wish to use my mill as a manual machine all I have to do is put the coarse feed handle back on, realease the tube from the Quill clamp and away I go.

Cost so far for my conversion has been $100 each motor times 4, $60 each encoder times 4, ($160 24volt 20amp servo's is CHEAP!) $45 each axis for belts and pulleys times 4

Hope that has not put your head in a spin!

Chich

leeroy
10-26-2006, 07:38 AM
G'day Chich

It's funny you should mention hydraulic cilinder tube...
Ever heard that saying "He just got lucky.." Well today it happened to me.:) I was searching through the offcut rack at work today for some material for a job and literaly triped over a 500mm long offcut of 90mm Dia ground chrome bar!! (we often do repairs/rebuilds on hydraulic cilinders etc). I raced back to my tool box for the Mike and guess what.. 89.995mm, parallel within half a hundreth over the length i need!!:rainfro:
A quick chat with the boss and for $80 it was a done deal. He also said that it was a readily avaliable size too so mabe this is an option for you also..
So now i'll machine off the chrome for 50mm on one end, press on and weld a collar and then drill full length and bore for the spindal bearings. Fortunatly, i have access to a big vertical TOS at work so i can cut some new rack teeth and hey presto, new Quill. :)
I think this will be a pretty tight fit though so mabe some honing / lapping of the bore to get the fit right.

As for the z axis drive, i like your idea. Fairly straight forward to do with the horozontal mill on your machine. The tube doubles nicely as a lead screw cover! and it's easy to disconect if need be.
Being able use the quill (in fact the whole machine) manualy is important to me also.
I do have one concern with this idea though..
Do you think the offset distance between the lead screw axis and the quill axis could add some side load or "kick over"? Especialy when the quill is at its fathest travel and "hanging out in mid air"? The ammount of kick (if any) would of course be limited to the fit of the quill and bore so the better we can make the fit in this area the less the possible kick.

Your drive motors sound like a real bargan! Do you know if Babinda01 has any more? I'll have to send him an e-mail and see..

Cheers

Leeroy

chich2
10-26-2006, 11:23 AM
Leeroy,
Thanks for the post. Firstly well done on the new spindle idea from the chromed cylinder rod. That should last for ever! You can also buy hydraulic cylinder components like guides and bushes to suit that rod if you did one day encounter some wear. If you go ahead with it I would love to see some pictures if it being made. Feel free to post them on this thread.

I agree with your point of some kick being imposed onto the quill from the screw being mounted out the side but I believe that a close fitting quill and bore should eliminate most if not all of this. In my design I will do everything to make the lead scew as close as possible to the quill. So far the only thing keeping it a distance away is due to the diameter of the large cogged pulley on the leadscrew.

Oh by the way I have forgotten to mention that I have removed the quill lock from the left side of the head and put it in the right side. I had to gently straighten the handle on it to work on the right side and also machine a bit off the end of the cast iron clamp piece to prevent it from protruding out the left side.

I think Babinda01 has 2 motors left but I will more that likely purchase them as spares. You could ask the manufacturer for a quote also. The motors are from Preslite Australia.

Contact for the motors:
Darryl Richards
Sales & Marketing Manager
CPC / Preslite
4-10 Hillwin Street
Reservoir 3073
Victoria
Ph: 039 460 6566
Fx: 039 460 6823
Mb: 0413 774335
Em: drichards@cpcauto.com.au
Web: www.cpcauto.com.au

The optical encoders are: E2-1000-315 from http://www.usdigital.com/. I also got shielded cable as well. Got em 6 days after I placed the order. They are 8mm bore which will mount straight onto my motor shafts. If you wanted to save some bucks you could just purchase the encoder wheel and the pickup and it may be a bit cheaper. Also if you get an incoder under 1000 counts per rev it's also cheaper. 1000 is a lot when you consider that the encoder wheel consists of 2 bands of 1000 counts 90 Deg out of phase which then gives you 4000 pulses plus direction. That's 0.09 of a degree accuracy on the position of the motor shaft. The encoders are incremental not absolute which means the incremental encoder only counts pulses. If you turn the power off and back on the encoder doesn't know where it left off. It only counts movement. An absolute encoder knows where it is after the power has been turned off and back on. Absolute is way more expensive than incremental. All you have to do with the incremental set up is leave the machine on or simply zero your co-ordinates once you power up each time.

I got back home today from my week away at work so I should be able to do some more on the mill this week.

Cheers
Chich

macona
10-26-2006, 04:13 PM
You know, this would be a great time to install a oneshot lube system. Since it will be CNC a motorized one would be even better. It will extend the life of the mill. And since everything is in pieces...

There is one more option for using the Z that you have not mentioned. It is the method that was used on my Supermax. It consists of a 4" ID air cylinder. the rod is removed replaced with the screw attached to the piston. the nut rotates on top of the cylinder on a thrust bearing. A timing pulley is fitted around the nut and is belt driven. Then the screw goes up into the knee. A pressure regulator is then used to adjust the pressure through the bottom port and balances the knee. Mine balances out at around 40 PSI (Guess that meand my knee/table weighs about 500 lbs. When the knee goes up the regualtor keeps it at 40 and when it goes down it dumps to keep it at 40. I think this is the regulator used on mine: http://store.norgren.com/US/en-US/cat3/skuR24-300-RGLA.html

Seems to work well. I have done some peck routines and it seems pretty responsive. Plus it leaves your head so you can do manual drilling and the like.

chich2
10-26-2006, 07:08 PM
macona,
Great post! Yes your system would work perfectly. Nice and lite too. A simple chart could be made up with pressure versus weight on the knee therefore eliminating the worry of heavy jobs and mass..... Good one!

A one shot lube system would be great. I will do a search for home made set ups but do you have any in mind that has details on how it is made?

Chich

macona
10-26-2006, 07:48 PM
Bijur (http://www.bijur.com) Is a pretty big name in oiling systems. I hear the parts are pretty cheap. You can get either manual or automatic pumps. These feed into manifolds with flow dividers and then steel lines to your points where you want oil. My mill has a chiba oiler hooked up to the servo power supply so whenever it comes on it starts pumping (Very slowly)Lines are also ran to the nuts to keep them nice and lubed (Well, not on mine anymore, I have ball screws now).

chich2
10-27-2006, 09:06 AM
macona,
Thanks for the info. By the way what do you bolkes pay un the US for ball screws. The cheapest ones I can find down under for 18dia X 5mm pitch come in at around $700.00 AU per preload nut assembly and a couple hundred bucks for all the screw.

Chich

leeroy
10-28-2006, 09:37 PM
G'day Guys

Thanks for the posts Macona. I think a lube system is a pretty good idea also. On my machine i have those little brass ball bearing oil valves. I think these should easily push out then tap the hole for a bsp pipe fitting. Probably run some 3mm anealed copper tube to a central manafold. If there is nothing comercialy avaliable, shoud be a fairly easy job to make up a small hand driven pump. Just give a few pumps before every job..

As for the air ram on the z axis, man what a great idea!!! :idea: Why didn't we think of that Chich?? I think a single 75mm ram mounted on the side of the knee would be ideal for my machine. Mabe even 2 smaller rams one on each side? There is room at the top of the knee lead screw to mount a pully for drive and plenty of room to mount the drive motor. At 100 psi a 75mm ram would give arround 320 kg of force.
If i can't find a ram at the right price, I think i can make a simple air ram from some extruded alloy tube. Use black delrin (Plastic) for the piston and some "O" ring seals. I have a length of 20mm Dia chrome bar salvaged from an old photo copier for the piston rod. Should be bale to find a supplier in Aus for the regulator valve. I will look into this idea further over the next week and will keep you guys posted..


Cheers

Leeroy

chich2
11-12-2006, 08:21 PM
Leeroy,
Yes the air ram idea pushes a very strong argument to automating the knee. In fact there are some industrial machines that use this system of offsetting weight. I have changed my mind and pretty much decided to go ahead with doing the knee over the quill on my my machine as I have plenty of ideas for different configurations on my mill that require the knee to be Z rather than the quill. I have a very acurate air regulator that reacts to very minor pressure variations and a friend of mine is sending a pneumatic cylinder to me for free so a Z knee for me is looking good at this point.

once I have Compleated the CNC Conversion of my HM-52 and done all 4 axis X,Y,Z knee and A, My future plans for my machine at this point are:

1. I will extend the dovetail ram all the way out. Bolted firmly underneath this will be an electric bench grinder. Hey presto! a rigid surface grinder. X axis will sweep backwards and forwards and Y will inch across once per back and forth stroke of X. Z knee will be depth of cut.

2. The HM-52 has a horozontal spindle. In the lathe I will machine a INT30 taper out of a large piece of high tensile stock. I will then place the taper into the horozontal spindle of the HM-52 Mill. I will bolt a turning tool to the table of my Mill and Hey presto! again My mill is now a CNC Lathe! I will turn the piece of stock to a face plate to hold a small 4 Jaw chuck. Sweet! I will then use the macine to CNC turn another INT30 taper which means I can make as many of them as I like. The second taper will go into the spindle and It will be a face plate for a small 3 jaw chuck.

3. Tool changer will be next. The tool changer will be bolted frmly to one end of the mill table pointing up. In this configuration It will be a tool changer for the quill. Standing up on it's edge it will be a tool changer for the horozontal spindle (if it fit's without smashing the other tools into the pillar). It will have a removable head so I can take off all the milling tools and put a head on it that holds turning tools. In this configuration it will look very similar to an industrial CNC lathe tool changer. So that leaves my machine as a very multi use machine. It will be a cnc knee mill, a cnc surface grinder, and a cnc lathe all in one! What a great machine!

chich2
11-12-2006, 09:02 PM
Well I'm back home for the week so I have been busy on the backlash quest again. I have stripped down the Milling machine to acsess the Y axis lead screw and nut. Since My mill is pulled apart to do this, the design of this nut has to be such that it can be entirely machined in the lathe. I will go through this photo by photo:

1. The standard y axis nut and a piece of brass stock that I made the new nut from.
2. The stock cleaned up and square.
3. I parted off a chunk. This will be the 2 nut half's
4. Faced the chunks flat and smooth.
5. Both segments bolted together and the mounting pin machined to size.
6. Nut squared up and boared and threaded.
7. and 8. Next was to ensure the surface the nut bolts to on the mill was paralell to the slide. I flipped the Y slide over and milled it flat using the quill and dovetail ram.
9. Made a new retainer washer nice and solid and increased the retainer thread size to M10. You can see how light the standard retainer is.
10. The finished product. The nut comes apart and you shim the 2 halves apart to achieve the correct preload. This can be done on the bench before it is installed and can be easily accessed from under the knee for future adjustment. All that is left to do on the nut is to dowel the 2 segments together.

Chich

macona
11-12-2006, 09:55 PM
I would try to use a cylinder co-axial with the leadscrew for the knee. This eliminates potential binding issues i using one or two cylinders elsewhere.

I would seriously rethink the idea of using the mill as a surface grinder. First there is the highly abrasive grinding dust. This WILL get everywhere and it will wear out your machine in no time. Second the x axis of a surface grinder is usually a rack and pinion affair. With the amount of going back and forth you are going to wear out you leadscrews in no time.

If you are really dedicated in needing a surface grinder you could always buid one from scratch. I have seen it done. Dont risk your mill for something like this!

chich2
11-12-2006, 11:38 PM
Macona,
Thanks for the concern. I have already designed these problems out by fully shielding the slide ways and containing the dust. The use of coolant almost compleatly eliminates dust as well. Secondly the amount of grinding I will do will be extreemly minimal.
The issue with binding is not that of the screw but however the slides. The HM-52 has a large dovetail slide about 500mm of contact. I assume binding in this area will not be an issue. Once again thanks for the concern but I am going to give it a go.

Chich

chich2
11-14-2006, 08:10 AM
Today I started the conversion of my Z axis. I am definately going ahead with converting the knee to cnc over the quill. I need a flat machined surface to bolt the servo mount and air cylinder to so I flipped over the knee and secured it to the machine up side down so I can face it using the dovetail ram. Up until tonight I have the knee in place and locked off square to the collumn. Tommorrow I will re-fit the dovetail ram and vertical spindle assembly and do the job of actually facing the knee.

I won't go through each photo and give a description but if you hold your mouse pointer over the thumbnail it will display the file name of the photo. The file name has a brief description of the photo.

Chich.

chich2
11-15-2006, 07:08 AM
Today I replaced the dovetail ram and vertical spindle assembly and bolted it down tight. Following that was another check for square then set up my small boring head to do some facing. The travel on the dovetail ram does not allow me to go any further back towards the column so I set the diameter of the boring as big as I could get it to fit inside the underside of the knee without it hitting any thing. I will either use a mount skinny enough to fit in the gap or carefullt grind and file away the radiused ends of the cut.

I have attached more photo's for you to look at. Once again hover your mouse over the thumbnail to see the file name description.

Chich

macona
11-15-2006, 11:50 AM
Yeah, coolant will work to help with the dust. One further note though, the bearings in a bench grinder will not be good enough to get a decent finish with the grinder. Probably best to build your own arbor. Maybe you can belt drive it and run it from your horiz spindle. something like 1:2 ought to get enough speed.

chich2
11-15-2006, 04:41 PM
Macona,

chich2
11-15-2006, 05:12 PM
Macona,
Thanks for the great info. I have been enquiring about suitable grinding wheels to use as a surface grinder. Eg. Type - Alli oxide, Sillica Carbide, size, grit, recomended speed, suitability to what kind of coolant. Do you know where I could get this type of information? I like your idea of using the horizontal spindle and belt driving a seperate arbor. Good one! Bearing manufactures like SKF and FAG make a ready to go bearing housing with a shaft on 2 bearings preloaded ready to go for this type of application. Normally used on high speed fans and simmilar assemblies this unit would be perfect for the job. Designation "PDN two-bearing housing". You can purchase just the housing by itself and fit 2 deep groove ball bearings and make a shaft to suit OR there is a part number for the complete assemblies.

I'm off back to work for another week so there will be no further progress post's from me until I get back next week,

Chich

leeroy
11-18-2006, 07:46 AM
G'day Guys

Well after two weeks of "A bit here and there" the new quill is done.

It was all pretty straight forward as the photos sudgest, with a few exceptions.

Firstly the dia of the chrome bar was 89.995mm as supplied. This was a almost perfect fit on the bore of my mill head(90.005mm).
However i had a feeling it might expand slightly when i drilled the center out. Which it did by almost 0.03mm!!!:confused: There must have been some residual stresses in the steel which i "releaved" when i drilled it out. This ment some honing of the bore was required to get the fit right, which was done with an automotive cilinder hone in a cordless drill.

Secondly, Hard chrome plated bar is REALLY FRIKIN HARD!!
When i went to cut the rack teeth, HSS hardly left a mark on it let alone cut it! I had to resort to using a few old solid carbide end mills, reground to a "v" shape. One roughing tool ground slightly undersize, held in the collet chuck and used in the conventional way, and another form tool carfully ground to fit the original teeth and held in my boring head. I also marked the teeth positions and using a 4" angle grinder, ground the some of the chrome away in each tooth position. This gave the cutter tip much better life.

The finial result is even better than expected. Due to the top end being about 0.005 larger than the rest (Mostly due to the interference fit of the top bearing) the quill actualy gets slightly tighter as it is lowered, just what i needed!:)

The name if each pic is a shot description.

Cheers

Leeroy

macona
11-18-2006, 12:41 PM
Nice work on the quill!

As for grinding wheel types I am not sure. I have never done surface grinding.

As for the spindle I think you are going to want something with anguar contac bearing. Even deep groove bearings still have some annular play. I tried deep groove on a lttle tool post frinder I made oce and coulnt get a finish worth a darn.

Maybe of you got one of those spindle housings and installed angular contact you could do it, though you are going to need an arbor that has a not to preload the bearings.

macona
11-18-2006, 12:42 PM
Oh yeah, ask over at www.practicalmachinist.com for info on wheel selection.

chich2
11-18-2006, 07:53 PM
Leeroy,
Well done!!!!!! Nice work on your new Quil.

Chich

chich2
11-25-2006, 07:39 AM
Well Im back home for another week. Today I drew some plans and made a bearing block to house an angular contact bearing for one part of my Z axis. I want to keep this machine usable as a manual machine so I have made the new components fit into place where the standard thrust bearings were and make sure the bevel gears still mesh correctly for the knee hand wheel. (crank)

My saw is not running at the moment so I parted off a piece of 2.5inch dia high tensile 4140 bar. Then made the bearing block out of that. The bearing is a 7205B angular contact bearing. It will be preloaded against another 7205B using the standard nuts that retain the bevel gear. As can be seen in the sketch.

That's all I got done today but will be back at it tomorrow.

Chich

chich2
11-26-2006, 09:47 AM
Thanks for the link Macona,
Today I machines up a few parts for the Z and Y axis's. For the Z axis I made some stepped collars and washers that go up hard against the angular contact bearings. The collars and washers space the spinning component away for the fixed race of the bearing. The spacer ring that sits up against the shoulder of the lead screw has the bottom angular contact bearing sitting on it supporting all the weight. Directly below it is where I mounted my toothed pulley to drive the screw. I do not want lubricant from the bearing getting onto the pulleys or belt so I made the bottom spacer with a lip seal running on the outside of it. On the inside of the spacer I machined a groove and installed an o-ring between the spacer and the shaft of the leadscrew.

The first photo is of all the new components sitting beside all the standard components. Both setups share the lead screw, bevel gear for the hand wheel and the 2 preload/lock nut's.

Second Pic is of all the new components on the lead screw.

No.3 is the Z axis drive pulley dialed up in the lathe ready to be machined.

4. Is the pulley with the Boss faced off.

5. is the pulley boared out and a slight tap fit onto the leadscrew.

6. Toothed pulley in position on Z axis lead screw. 2 M6 grub screws will later secure the pulley into position.

7. Is my pneumatic cylinder that I'll use to assist lifting the weight of my knee. In this photo I have cut one clevis eye off the bottom using a hacksaw. The cylinder has a 100mm piston and 400mm stroke from a 25mm rod.

8. I decided to do some work on the Y asis as well so I chucked the standard bearing mount and dialed it true.

9. I then bored out the Y axis bearing mount to fit 2 x 7203B angular contact bearings. The 2 bearings seat up against a shoulder inside the mount back to back for preloading. I faced the mount true to the axis in one operation so later when I attach the motor mount it will all be square.

That is it for today. I have drawn up a sketch for the servo mount and the cylinder mount an will start on that tomorrow.



Chich

chich2
11-28-2006, 05:28 PM
Yesterday I removed the dovetail ram and spindle assembly like last time and then removed the knee. I placed the knee on some card board out in the yard and marked out where I need to cut away from the knee to fit the pneumatic cylinder. Once I cut out the bottom I then took several small cuts into the 25mm web that runs up the back of the inner knee. I did this with a 4" angle grinder fitted with a 1mm thick cut off wheel. It was just a matter of several light taps with a small hammer until the web pieces broke away. I did not want any stress cracks to develop into the good part of the knee so I used many cuts and only light tapping with the hammer. Once the web was removed I ground the web flat and smooth and then painted the bare cast iron.

The next step was to put the machine back together. Once I got the knee on I adjusted the gib and then lowed the knee onto a piece of hard wood. Next to go on was the Y axis dovetail. Now that I can secure the Y axis I set up my boring head and machined the hole that holds the Y axis lead nut deeper. I needed to do this because I made a much more solid retaining washer and a bigger bolt than the standard one. (There is a photo of it in a previous post).

I then assembled the Y axis lead screw, bearing mount and then tightened the antibacklash nut tightly to the machine. I placed a light preload onto the angular contact bearings and gave the Y axis a go by hand. I am very happy with how smoothly and easily it moves. Keep in mind that there is almost no weight on it at the moment so it may stiffen up a bit when the X axis and swivel is sitting on it too.

Chich

macona
12-09-2006, 11:55 PM
Hey, I put up a post with my progress on the refurb of my mill:

http://www.cnczone.com/forums/showthread.php?t=28668

On the bottom there is a picture of the air assist ball screw.

chich2
12-11-2006, 06:51 AM
Great thread macona. You have certainly got a great project there with your supermax. The air assisted ball screw is a good set up.

Keep up the good work,
Chich.

chich2
12-20-2006, 07:53 AM
Haven't had a post in a while so here is an update on my cnc conversion.

I ordered a precision pressure regulator from SMC. It is acurate to the set pressure setting within 0.5% and repeatibility of 0.2%. I have made a mounting plate that the cylinder rod pushes on and bolted it in firmly to the under side of the knee. When I say underside I mean directly under the Y axis slide ways. Basicaly the cylinder gives me full stroke of the Z axis. I have cut a hole in the casting through the top of the coolant tank and sat the cylinder on the floor of the coolant tank. The floor of the coolant tank casting is about 20mm thick with some very heavy webbing so there is plenty of stregth there. The cylinder is set up to run parallel with the Z axis dovetail slide. I milled off some of the aluminium from the sides of the cylinder ends and I also milled quite a bit off the Z lead screw post. In the photo's you will also see half of the Z axis servo aragement coming together. You will see the servo pulley grub screwed with 2 M6 grub screws 90deg apart. I milled 2 small flats on the screw boss to take the pulley grub screws. I piped the regulator up with brass gas compression fittings and copper tube.

When it came time to try it out I backed the regulator off and turned on the air supply. I then slowly screwed up the pressure on the regulator and the handwheel on the knee became easier and easier to turn. Now when I raise the knee, the regulator fills the cylinder and when I lower the knee the regulator vents the excess pressure. The regulator has a very controll over the pressure in the cylinder.

Here are some pictures.

Chich

chich2
12-20-2006, 07:19 PM
Today I made and installed a chip cover over my Y bedway. This should keep most of the chips and swarf off the beds. There are 2 photo's. A before and an after shot.




Chich

chich2
12-20-2006, 07:26 PM
I have noticed that the HM-52 has only 1 gib adjusting screw on the knee. What happens is when you make a very small up and down movement on the knee you will see the gib actually stay's still for a very short moment as the knee moves, then the adjusting screw hits the jib and starts to moove it allong the dovetail. This leads to three things. First one is uneven wear. Second is that when the knee goes down the gib is slightly loose. when the knee goes up the gib get's slightly tighter. The third thing is that there will be a tendancy for the front of the knee (where the handwheel is) to drop down very slightly. It wont be much but the top of your knee will no longer be square to the colum of your mill untill you either travel the knee up or tighten the locks on the side of the slide.

I have fixed this problem by adding a second adjuster to the bottom of the knee. I had to chip away the bog filler from the underside of the knee and file it flat with a course file.


Chich

chich2
12-21-2006, 08:41 AM
Here is the start of my servo mount. I milled some mild steel down to 20mm thick then bored a hole in 52.02mm diameter to house the bottom Z angular bearing and oil seal. I will try to show all this at a later date when it is all installed.



Chich

chich2
12-22-2006, 08:27 AM
I didn't get much done on the machine today. I did manage to drill and tap some holes to mount the servo and I also drilled and counterbored the holes that connect the mounting plate to the mill.

Chich

FPV_GTp
01-01-2007, 06:48 PM
hi

Nice work chick2

cheers

chich2
01-02-2007, 06:05 PM
Thanks FPV GTp,
I am at work at the moment and will be back home this friday. I will be adding some new post's to this thread during the next week.

Chich

chich2
01-05-2007, 06:08 PM
Here are some more pictures of my conversion. Next step was to mount the servo motor to the mounting plate. I made the servo mount to bolt securely to the flat surface I milled under there, back when I turned the knee over. I set the preload on the 2 angular contact bearings I put on Z axis lead screw (as shown in a previous post). Once this was done I then slid the servo mounting plate over the bearing clamped the plate tightly and marked the holes that secure the plate to the flat milled surface. I then removed the plate and drilled and taped the holes. This eliminates any binding issues caused by an incorrectly positioned mounting plate putting side load on the bottom angular contact bearing. Keep in mind that this mounting plate also doubles up as a bearing and lip seal housing for the Z axis lead screw.

The drive belt has to be tentioned, so the plan was to make the servo able to be slid back and forth allong the mounting plate on slotted holes. This was achieved by milling out 2 pieces of 25mm RHS box section. This can be seen in the first photo. The belt had to clear everything so if the belt did ever slap I had to make sure there was plenty of space for it to run in.

The rest of the photo's are pretty straight forwarward except for photo 5. Because the boss diameter on the small 14 thoothed pulley is so small and the shaft size on my servo is 10mm, I was concerned with how little wall thickness I had for the grub screw to hold into. Because of this I had to (very unwillingly) also add a grub screw hole in the cogged section of the pulley.(wedge) I cleared away any burs and made sure it sat down deep enough that it would not touch the belt when it runs. Guess I'll see what happens when it's running.

Chich

epineh
01-05-2007, 06:18 PM
Looking good Chich, make sure you leave enough room for the tool changer!!!

Russell.

chich2
01-05-2007, 06:40 PM
Khaa Haa! Yes russ I WILL!! Definately have to use one of your micro controllers for that one! I just read your thread and find it VERY interesting.

Good work!

Chich

chich2
01-06-2007, 09:42 AM
Today I finished the Z axis servo mount. It was a matter of setting the pressure on the air cylinder and locking the Z axis dovetail clamps to lock the knee into position, then disconnect the Z lead screw form the machine and screw it down. Once the screw was low enough, then came re-mounting the Z screw pulley with it's 2 grub screws and passing a new belt over the screw. I then put it all back together and adjusted the preload on the Z angular contacts and mounted the servo and released the dovetail clamp locks. A quick belt tension up and we're in buisness. I wanted to see how it would go so I connected the 24volt servo to a 12 volt battery, quickly checked the air pressure to the cylinger and give the motor a quick tickle up with 12volts. BAM! up it went! Switch the wires over and down it went. Pretty crude way of testing but I could hear the precision regulator doing it's thing very quickly adjusting to the pressure rise and fall in the cylinder as the knee moved. Can't wait to see it going by CNC!!!!!! :banana:


Chich

chich2
01-06-2007, 05:03 PM
Because my air asist cylinder goes through the base of my mill and sit's on the floor of the coolant tank, there is a good chance chips and swarf will get into the coolant tank. So I made an oil resistant neoprene cover to go over the gaps. This was firstly done by measuring it all up and cutting out a cardboard template. Once the template fitted, then the cover was cut out of neoprene.

Chich

chich2
01-07-2007, 07:43 AM
Today I started the X axis servo mount. The first step was to make something to support the end of the X axis lead screw when the table is fully traversed to the right. In this instance the only support the screw has is the 2 anti backlash nuts mounted to the swivel. I have about 600mm of unsupported screw that needs to be held as the servo belt will be pulling sideways on the lead screw. I decided to firstly bore out the cogged pulley and slide it onto the shaft. This allowed me to see exactly where the servo motor would and wouldn't fit. Following that a few measurements of the rectangular box pipe that I have in the rack for the mounts, I came up with a quick scketch.

I cut a piece of steel, milled all the rust off it and milled it to size. Drilled the 2 bolt mounting holes and used my boring head to bore a hole in the plate for a slide fit on my steady bearing (6004 2RS). Bolted it on and gave it a go..... Good thing!

Chich

chich2
01-08-2007, 08:26 AM
Today I continued work on the X axis servo mount. Firstly I cut 2 lengths of 150 X 50 RHS 270mm long (6" X 2" Rolled Hollow Section). The servo shaft needs to be parallel to the lead screw so an easy way to do this is to machine one side of the RHS flat and secure it to the machine and attach the servo to the same side. I removed the limit switch for the standard Hafco power feed unit as it is no longer needed. The table travel stops were removed as they are also no longer needed, and one X axis table lock handles removed (one will do). Next was to drill and bore all the holes and bolt it on. Hopefully tomorrow I will attach the motor and give it a test run.

Same old story, just hover your pointer over the picture thumbnail to get a description of the photo.


Chich

chich2
01-09-2007, 09:30 PM
Yesterday I finished the X axis servo mount. This was done by marking out the RHS on the machine to determine where the motor would fit without crashing into anything. After that came fitting that area in with the belt length and pulley centers. This gave me an arc around the leadscrew pulley that the servo wolud fit along. I then milled 2 freehand arcs in the RHS to swing the motor stud and drive shaft in. (if only I had a CNC mill!!!!!! :D ) Followed by a hole for the other stud.
Next step was to re-configure the servo motor so the mounting studs protrude out the drive shaft end. This was done by pulling the motor apart and swapping over the end plates of the motor. (One end plate has studs - One doesn't) While the motor was apart I machined the back end plate to mount the encoder onto and swapped the brush mounting assembly to the other end plate.
Next step was to bore out the motor pulley and drill and tap 2 M4 grub screw holes.
Then it was a matter of bolting it all together.
I couldn't resist the urge to give it a go so I connected the 24 volt motor to 12 volts and tried it out - then I gave it a go with 24 volts and :eek: that's fast! Well fast for me.

Very happy with the result.:banana:

Chich

chich2
01-12-2007, 12:28 AM
Yesterday I finished the Y axis servo mount. This was done in a very similar way the X axis was done except this time I cut a big window in the front. This will later be covered by a sheet steel or clear plastic cover. The nut that holds the hand wheel on is what is used to preload the 2 angular contact bearings on the lead screw so I machined a boss onto the timing pulley to prevent the pulley rubbing on the outer race and bearing housing. I also machined an oversize keyway in the pulley so it can pass over the key in the shaft that the hand wheel drives. All the pulleys are secured by 2 grubscrews. I ran out of time to test it before I had to go to work but it mooves freely by hand so the motor should moove it. Here are some pictures.


Chich

chich2
01-19-2007, 05:06 PM
Yesterday I ordered my drive electronics. I purchased everything I need from CNC Teknix in Oak Flats near Sydney, Australia. I spoke to a bloke named Dave. He was very helpfull. I purchased 4 Tek10 - 15-80V 25A Servo Drives, A breakout board and registration for Mach3.

Chich

FPV_GTp
01-19-2007, 05:41 PM
hi

Chich2 very nice work , love the pneumatic cylinder assisting in the lifting of the heavy bed ( Z direction ) of the milling machine.

Still trying to work out how you eliminated the play in the lead screws of the X and Y axis , i will have to read these posts several times to understand what you have done.

Tek10 - 15-80V 25A Servo Drive $324.50 drivers not cheap at all but a good choice , any reason you chose Dave's drivers over some of the other units out there. Say Gecko , Rutex and so on.

I will follower this thread to the end as i have a Pacific FT-2 universal milling machine i will be converting soon.

Keep up the good work

cheers

chich2
01-19-2007, 06:11 PM
FPV GTp,
Thanks for your post. The anti backlash nuts are different for the X and Y axis. The X axis is like screwing 2 nuts together on a thread. As they touch each other, one nut will be pushed up against the flank of lets say the left side of the thread and the other nut will push up against the right flank of the thread, thus eliminating backlash. Some people put a spring between 2 nuts to do the same job.
The Y axis is almost the same but instead of screwing the nuts to move their position along the thread helix, the Y axis nut has jacking screws between the 2 nuts and I simply adjust the 2 nuts apart via the jacking screws to eliminate the backlash.

The CNC Teknix hardware must actually be going up in price. The Tek 10 I actually purchased was at last years price of around $280AU or round about there. Babinda01 here at the zone does CNC conversions as a living and literally lives a stones throw from my place. I believe Babinda01 and CNC Teknix have a long working relationship and they are currently working on a system which will give encoder feedback back to the PC. This means the PC now knows exactly where the position of the machine is and doesn't just assume that the servo drives made it in time. It also allows the user to power down the servo drives and make a manual handwheel movement and the PC will know the position the table is now in. The new system will also be a true DRO. Dave informed me that I can upgrade to the new system for $300AU when it is released. I just seperate the 2 cards on each servo drive and send them the top one and they will send me the new ones and new controll card. The new system is interfaced via USB.

My system requires frequent adjustment as the lead screws in the machine wear the brass nuts away quite rapidly. I am only doing it this way until I can find cheap ball screws to install (which I have just found)

I personally like the Pacific mills. You are lucky to have one.

Chich

FPV_GTp
01-19-2007, 06:22 PM
hi
Chick2 , ok understand some of the reasons , but was going to ask why didn't you use ball screws from the start.

I found most bearing places here in Australia are asking a fortune for ball screws.

I got in touch with www.nookindustries.com and was quoted far cheaper like 3 times cheap delivered to my door from overseas than what i could buy here in Australia . Bloody amazing someone is trying to make a packet.

Out of curiousity what brand of ball screws you planning on using and who did you source them from ?

cheers

chich2
01-19-2007, 06:39 PM
FPV GTp,
I have a friend in the bearing industry and he tried to source me cheap ballscrews. The cheapest he could find me was $700 Au PER NUT!!! I stayed on the case and got quotes from many manufacturers in the US, China and Japan. I finished up on the Dannerher website who are the distributers of Thomson Ballscrews. Their Australian distributers wern't realy much help but were a wealth of information. I finished talking to Hagen at Action Bearings in Breyside NSW. Thompson make a realy cheap screw and nut in the 1" size. I would say it is so cheap because it's such a common size. Metric was more expensive and so was left hand thread and nuts. So in the end I went with 1"Dia X 1/4 pitch screw @$120 per/meter and 6 non-preloaded ballnuts @ $90 each.

I have to say I'm pretty happy with that. I have done a lot of searching and I am going ahead with that quote.

Chich

chich2
01-22-2007, 07:12 AM
Today I mounted the first US Digital optical shaft encoder onto the X axis drive motor. I machined up a small brass bush to locate the mounting plate true to the motor shaft. I drilled and taped 2 holes in the motor end plate to secure the encoder mounting plate. I then cleaned all the surfaces with electrical contact cleaner and applied glue to the encodor mounting plate. I then slid the backing plate along the brass bush and pushed it up hard against the motor end plate and tightened the 2 screws and allowed the glue to set.

Next was to slip the spacer clip onto the shaft. The clip is supplied in the kit by US Digital. The clip position's the encoder disk just the right distance from the mounting plate so when you add the optical pickup the disk is in the right position and does not rub on the pickup. The cover goes on next followed by 2 supplied screws.

Chich

chich2
01-25-2007, 05:22 AM
Yesterday, my servo drives arrived in the mail from CNC Teknix. I orderd them Friday and got them Wednesday. In the bag was 4 Tek10's and the breakout board. CNC Teknix e-mailed me a diagram of the pin outs for the electronics and my Mach3 licence.

Next I Drove to Cairns to Boltmasters to pick up some #4-48 UNF grub screws to secure my optical encoder disk's to the motor shafts. The Preslite motors I am using have a huge flat milled on the shaft and the grubscrews that came in the encoders from US Digital are too short. Thanks Boltmasters!

From Cairns I went to Innisfail to see a friend from Custom Line Computers. I went there to purchase a CPU for my Mach3 PC expecting to pay around $100AU for the processor and labour to find one that suits one of my motherboards. I have a stockpile of old PC's of different ages, some with processors, some without. All of them under 600Mhz. Finished up walking out of Custom Line Computers with a Pentium 4, 2Ghz processor, motherboard - everything onboard, brand new 512Mb ram, Brand new 500Watt power supply, brand new CPU fan and heatsink, CD Burner, and flopy drive ALL IN A CASE (except for the new stuff still in the box) for $200AU

I took it home and put it all together. I formatted an old 6Gig hard drive I had stashed in the stockpile and put it in the PC. By strictly following all the instalation instructions from the Mach3 website I installed WinXP Pro, Modified all the settings as per the Mach3 optimisation file and installed Mach3.

Last Friday I also ordered my Thomson Ball screws from Action Bearings but they will be about 3 weeks as they have to come from you blokes in USA.

I am back at work now and wont be back home until late next week so I hope this week goes quick.

Chich

chich2
02-04-2007, 07:49 AM
Today I had some time to work on the machine. I decided to finish off installing all the encoders to the 4 motors. I made up 4 mounting brackets and attached them. I had to take the end plates off the motors to drill and tap them. Then screw it all together. I had to make sure the M4 screw holds the motor end cover on doesn't touch the US Digital encoder cover. I finished up with a 1mm gap between the screw and the encoder cover. The black motor end cover is now pulled up tight onto an o-ring on the motor by a brass nut that I machined. The hole doesn't go right through the nut, it is blind so that it seals better. I will add a fiber washer to the nut or maybe a small O-ring.

Here are some pictures.

Chich

chich2
02-04-2007, 08:15 AM
I have always been woried that grease from the angular contact bearings will fling out across the face of the large timing pulleys and go everywhere contaminating the belts. I sealed the Z axis but never got around to doing the Y axis......................... till now. I removed the pulley, set it up in the lathe and machined a grove to press in a lip seal. When the pulley is installed the seal goes over the outside of the bearing housing that holds the bearings. Now grease is contained even if the berings are over greased.



Chich

phomann
02-04-2007, 09:06 PM
Hi Chris,

Nice conversion. I was looking for a way to mount some encoders on stepper motors I have. Your technique was provided a solution. Thanks for that.

When you get around to wanting to control the spindle speed from Mach, have a look at the DigiSpeed-XL.

http://homanndesigns.com/store/index.php?main_page=product_info&cPath=1&products_id=2

Being a fellow Aussie, you can always give me a call if you have any questions.

Cheers,

Peter.

chich2
02-05-2007, 05:55 PM
Thanks Peter,
I will definately take a look at your site. Variable speed spindle is on the horizon for this machine.

Thanks for the post,
Chich

chich2
02-05-2007, 06:24 PM
The standard Hafco Hand wheels consist of a steel bush with a key way cut in it. Moulded around the steel bush is a black bakerlite type material to make the wheel. The handwheel isn't molded true to the bush and therefore looks like it wobbles slightly when it turns. You dont normally notice it when using a manual machine because your not looking at it. When I put power to the motor to test it, the handwheel was the first thing I saw. Looked like it was loose.

To correct this, I held a piece of mild steel in the 3 jaw and machined a stub on the end with a slight interferance fit to the hand wheel. This stub would now be true to the lathe. I taped the handwheel on to the stub, removed the handle and then machined all the surfaces of the handwheel. Using a 3 leg gear puller I removed the hand wheel and spun it around to do the other side. A quick clean up with a file, some sand paper and a spray of WD40 made it look black and shiney.

Now the hand wheel spins the way it should.

Chich

phomann
02-05-2007, 07:14 PM
Thanks Peter,
I will definately take a look at your site. Variable speed spindle is on the horizon for this machine.

Thanks for the post,
Chich


Chich,

While you are there, have a look at the ModIO.

http://homanndesigns.com/store/index.php?main_page=product_info&cPath=2&products_id=4


It expands the number of inputs and oupts you can control. Additionally, multiple ModIOs may be controlled via Mach.

It is very useful for adding a Pendant to your system.

Cheers,

Peter.

chich2
02-06-2007, 09:07 AM
phomann,
Funy you mention it. Turns out yesterday I ordered a relay board and an opto board from CNC Teknix. They were cheap and make wireing up easy and neat so I thought why not. The 2 boards simply mount to the top of my current breakout board and are connected via ribbon cable. The boards should be here tomorrow or the next day and will provide the same function.

Thanks for the info,
Chich

chich2
02-06-2007, 09:13 AM
Today I started making my servo driver electronics enclosure. I took an old PC tower case and removed all the old hardware. Next I started fitting everything in the box to see if it would fit. I cut out any metal that was in the way and filed the sharp edges.

The fan is an old PC cooling fan, the MASSIVE heat sink I got from "Epineh" here at the zone, Thanks again Russ. The power supply is again an old PC one. It will supply power to the TEK10 servo driver to keep the logic powered up. It will also power any cooling fans I install. Please note that the PC power supply is only powering the logic in the card - not the servo motor itself.

I measured up the TEK10's and drilled and tapped the holes in the heat sink, Screwed the heat sink into the PC enclosure and sat the TEK10's on to see how it looked. In went the PC power suply and the cooling fan.

Tomorrow I will get the right length screws and some heat transferr paste and screw the servo drives down to the heatsink.

Chich

phomann
02-06-2007, 03:27 PM
phomann,
Funy you mention it. Turns out yesterday I ordered a relay board and an opto board from CNC Teknix. They were cheap and make wireing up easy and neat so I thought why not. The 2 boards simply mount to the top of my current breakout board and are connected via ribbon cable. The boards should be here tomorrow or the next day and will provide the same function.

Thanks for the info,
Chich

Chich,

Good to see you have it sorted. THings seem to be coming along quite well.

Cheers,

Peter.

chich2
02-06-2007, 11:59 PM
Thanks Peter.
Today my Relay board and opto board came in the mail from CNC Teknix. Both boards came pre assembled with cables, plugs and mounting screws. (stand off's) It's a simple process to connect them to the breakout board. You simply plug in the 2 fitted ribon cables, line up the stand off's with the mounting holes in the breakout board and screw it together. Pretty cool.:rainfro:


Here are some pictures.

Chich

chich2
02-10-2007, 06:32 PM
I made a preforated screen for the back of my electronics enclosure.
Measured up the gap, made a drawing, cut it out, bent it up and screwed it in.
I then marked out where the plugs and sockets go and milled them out.
Screwed it all back together and secured the cooling fan as well.

Chich

chich2
02-10-2007, 06:50 PM
To get the plugs and connectors to poke through the preforated screen far enough and to fit the cooling fan, the heat sink had to be milled shorter.
I loosened the swivel bolts that secure the dovetail ram to the column and spun the head out of the way. I then put my multi tooth cutter in the horizontal spindle, clamped the heat sink to the table and milled the heat sink to the required length.

Chich

chich2
02-12-2007, 07:31 AM
More work on my electronics enclosure today. Ran all the logic power, encoder cables and ribbon cables to the Tek10's. Started to add the servo input power into the drives as well. Painted the anodised aluminium main frame of the Tek10's were the big transistors are with heat transfer paste so they make good thermal contact with the heat sink. Added power to the cooling fan which comes from a plug on the relay board. Tried my best to run all the controll cables away from the servo motor cables to minimise any bad signal noise. Ran all the encoder cable shields to ground. Made a plug and cable to re-position the indicator LED's from the relay board to the front of the enclosure. Drilled through the plastic insert in the front and poked the LED's through.


Chich

chich2
02-15-2007, 09:02 AM
Today I measured up my computer box, electronics enclosure, batteries, Battery charger, computer monitor and keyboard and designed a cabinet to put them all in. I then cut all the steel and welded it all together. I then screwed the shelf's onto the frame. Tomorrow I will attach the sides and the door. The idea is that when the doors are closed, everything will be sealed away from dust. The top part will have a seperate door to the bottom part.

Chich.

chich2
02-16-2007, 04:54 AM
Today I added a pull out shelf for a keyboard and mouse. I also screwed the sides onto the cabinet. Couldn't miss a photo oportunity so I stuffed everything in and saw how it fit. Under the rag on the bottom are 4 big 12Volt lead acid batteries. They will give me the 24volts I require to run my servo's. They will be held up by the smart charger you see between the electronics enclosure and the computer tower. Yet to test the power supply but the batteries are 90amp hours each so combined should be good for 360Amp hours at 24 volts. That's a lot of grunt! The max current rating of each of my motors is 20amps and the safety setting in the servo drives will not let the motor current go that high when correctly set. The battery charger is good up to 10amp's continueous at 24Volts.

I didn't get up to the stage of attaching the door. Maybe over the week end.


Chich

epineh
02-18-2007, 12:29 AM
Hey Chich, I did the first test run of your little PCB to mount your power on LED's today, I am not completely happy with it, but here it is...I am going to remake and clean it up a little. I also need to work out a tinning method.

Russell.

epineh
02-18-2007, 01:44 AM
Take two... the resist is still on until I am ready to tin.

chich2
02-18-2007, 08:05 AM
Thanks Russ! Your boards are rapidly getting better and better..... Is that your 2nd board you've ever printed????? Pretty impressive I say! Looks very profesional. Should look flash when someone looks inside the electronics box and see's my name printed into the circut board inside. That's so cool!

Well Done.

Any one interested in printing their own circuit boards should DEFINATELY look at one of Russell's (epineh) thread here at CNC Zone http://www.cnczone.com/forums/showthread.php?t=30951 and you will be inspired! Forget routing them! Russell made this board from start to finish in about 5 minutes.

Chich

chich2
02-20-2007, 08:39 AM
Did a bit more work to my mill today. I purchased a Battery isolator that allows me to switch between bateries and also compleatly isolate them at the end of the day when I shut the machine down. The Switch can be set to battery 1, Battery 2, Battery 1 and 2, or off. I mounted it inside the cabinet down where the batteries are for ease of wireing.

I also wired up my servo motors today. I ran 3/4" spiral "Anaconda"
(1" OD) from the cabinet to the mill and ran my shielded encoder cables and servo power cables to each motor. The anaconda terminates on the machine either to a junction box for Z and Yaxis, and to the servo mount for the X axis.
Took a lot of time to crimp on all the lugs for the encoder plug. Those litte lugs are a pain......



Chich

macona
02-20-2007, 06:33 PM
Wait a minute, your running this thing on batteries? Why???

chich2
02-21-2007, 01:11 AM
Good question macona. The quick answer is probably "Why not?" I have been searching for a transformer or transformers big enough to run the motors without much luck. In the very early satges of the conversion when I first started out, Epineh here at the zone gave me the 4 huge batteries to get me by until I came across a power suply. The Batteries turned out to be so powerfull that they are going to easily run my mill for the time span I need. They will supply NO ripple at all even at maximum amps so I will have extreemly clean power and best of all....... My entire power supply was FREE!

Chich

LUCKY13
02-21-2007, 07:26 AM
What size,type & volts are these batteries? Very interesting, I have never seen anyone do this & after thinking about it , this could have its purposes.




Jess

LeeWay
02-21-2007, 09:33 AM
I know smaller motor controllers are affordable, but I was curious about another unorthodox way of setting up a dc motor. If you happen to have two of the same type motors, say treadmill motors. Can you turn one backwards with a standard ac motor and expect it to supply the proper dc current to the second motor? I have my controller already and only one motor, but I was just curious about this.
Nice work, BTW.

epineh
02-21-2007, 04:02 PM
What size,type & volts are these batteries? Very interesting, I have never seen anyone do this & after thinking about it , this could have its purposes.

Jess

Hi Jess, I supplied the batteries for Chich, they are 12Volt, 90Amp/hr Lealed Lead Acid batteries, they are from redundant equipment I de-commissioned.

He has 4 of them so he has two 24Volt "strings" of 2 batteries that he can run individually or together, so theoretically he could pull 180 amps for an hour, though I am never one for manufacturer ratings, real world current/time will be a bit less, also they are a couple of years old, but they will provide a nice ripple free supply that should run Chich's machine for about 6-7 hours with no re-charge and no damage to the batteries. They don't like getting totally discharged but I will probably put some kind of monitoring on later on, and he has a charger he can run to "top up" the batteries for the long machining sessions.

Leeway, theoretically you could do that, but there are always losses, which will take the form of heat, both in the primary AC motor, the generating DC motor, and the final DC motor. It would work, a bit of smoothing on the output of the generating motor would help.

A place where I used to work had just that setup for a large stick welder, a 3-phase motor spinning a DC generator. It was noisy, ugly and HEAVY but damn it was a nice welder to use.

Russell.

macona
03-07-2007, 06:04 PM
Those welders were made by Hobart and Lincoln mostly. Many are still in use today. I havnt repaired any lately though. They are beautiful for arc gouging.

But they are HEAVY and huge, especially for the output. Now you can get a machine that weighs literally a tenth and has the same output.

chich2
03-10-2007, 06:50 AM
Been a while since I last posted. Been pretty busy with all sort's of things. The Mill conversion has come along well. Have finished wiring everything up. I may have had a grounding issue so I went crazy with earthing EVERYTHING! Had some help from Epineh and Babinda01 here at the zone and got 2 axis up and running. Z axis is not going as the motor does not have enough torque to drive the knee without using ballscrews and a bigger motor. My ballscrews left the vendor last week so they should be home when I get home next week. Babinda01 gave me a bigger motor to put on Z and I will mount it next week. I have so far made some g-code of some text like my sister's and my name. I have also made some code of some circles using one of the Mach3 wizards and made it into a quick video. Hopefully this link works to my video of X and Y drawing small circles.

http://www.youtube.com/watch?v=Bc1D_4WiHwo

Chich

epineh
03-10-2007, 08:07 AM
Cool, I know of one sleepy little sugar town that will be buzzing with the sweet sound of computer controlled machines in the not too distant future.

Hopefully the weather will be good for CNC when you are next out :)

Russell.

chich2
03-18-2007, 08:35 AM
Well I'm home again for a few days and i'm about to do some more work on the mill. My ball screws arrived safe and sound and I have pulled apart and cleaned the bigger motor for my Z axis that babinda01 gave me. Hopefully tomorrow I will mount the encoder to the motor and fit the pulley. Then I can start wokring on fitting the ballscrews to the machine.

Here are some pix.

Chich

chich2
03-20-2007, 08:12 AM
Today I worked on a bigger servo motor for my z axis. Firstly I cleand out the bore of the hollow shaft of the motor with a welding rod and sand paper in a cordless drill. Then I measured the bore of the shaft and made 2 stub shafts (with flats) to go inside each end of the motor. 1 stub holds the pulley and the other one holds the encoder disk. Because the hole in the motor end plate was bigger than my encoder, this left nothing to secure the encoder backing plate to. So I made a brass mount to connect the encoder to which has a neat spigot to locate it to the motor. (not that it needs to be...just looks neat!) I then taped the stubs into the motor shaft with a soft hammer and grubscrewed them in tight.

Hover your pointer over the thumbnail to see a description.


Chich

chich2
03-20-2007, 08:21 AM
I could talk this to death so I won't. I fitted the stubs to the motor and set up the encoder and cover. Photo's 3 to 8 basically show how to mount a USDigital encoder. It is very easy to do so here are some pix of me doing it.


Once again hover your pointer over the thumbnail for a description.


Chich

chich2
03-20-2007, 08:29 AM
Up the buisness end we have the pulley. Because I believe I will need a wider belt for this axis in the future, I didn't want to cut the servo shaft any shorter than what it already is. I decided to put the pulley out on the end for now. To do this I taped the stub in with a copper hammer and grubscrewed it in tight. Then fitted the pulley and grub screwd it to the stub.


Chich

stihl88
03-29-2007, 01:01 PM
Awesome work Chic, i have the same Milling Machine as this. Ive only had it for 2 days and am a complete n00b when it comes to milling. So if i sound like a complete beginner it's because i am. Following your venture to turn your mill into a CNC has inspired me to seek out some sought of tafe classes or similar training.

I don't mean to spamidy spam your thread mate but where would i start in the way of learning the ways of the Milling Machine? Before i even comprehend doing something like this to the it.

Cheers :)

chich2
03-30-2007, 09:43 AM
stihl88,
Thanks for your post. Questions are always welcome!
I believe the best start you can get to learn your milling machine is to do exactly what you said above...... Take a TAFE class in machining and milling and you will learn almost everything you need to know to machine some pretty cool stuff! You will learn about diferent materials and how to machine them with the correct tools and their application. When I did my apprenticeship I think the subject module for introduction machining was NBB06 or some thing like that. Check with your local colledge and they will recomend the right subjects.

Chich

stihl88
03-30-2007, 08:31 PM
Thanks Chich

I think i will go and do a tafe course.
I have the 75th Anniversary model Hafco Lathe, similar setup to yourself!

Incidently, how much do you think you have spent so far on converting your Mill to a cnc? Excluding the Computer.

chich2
03-31-2007, 07:29 PM
stihl88,
Rough costs so far in Australian dollars are:
Mill, freight $4600
4 Servo motors, encoders $640 (total)
Drives, breakout, relay, opto boards $1400
Ball screws, nuts $900
Steel, wire, plugs, connectors, misc, $500
Many Many Many Many Many Many Many Many Many Many Hours of my time........... $Priceless (sounds like a Mastercard Add!!)

That's over $8000. I'm sure you can find a used CNC mill for that price that will be far Far better than what i'm building. My constraints are space to put it in. No 3 phase power, ability to relocate the machine if I need to moove and what am I going to do with a fully fledged industrial cnc mill?
It's not cheap but a blokes gotta have his hobbies.

The up side is I will have a brand new CNC mill for $8000 that "I" built. I have had a great time so far building it and hopefully you will too.

Just remember, be preparied to fork out some cash.

Chich

chich2
03-31-2007, 07:40 PM
Yesterday I started mounting a ball screw to my Z axis. After a lot of measuring I drew a plan and started machining up some of the parts. If my calculations are correct my Z axis travel should be 350mm. I could have made it more if I made the position of the lead nut lower in the post. This would then allow the knee to go lower. A longer lead screw could then be made to cover longer distance of travel to raise the knee as far up and down as possible. The problem this creates is when the knee is fully lowered to it's new lower position than normal, the lead screw would hit the groung the mill is sitting on. A stand would have to be made to sit the entire Mill on. This would have raised the mill off the ground and allowed the Z lead screw to protrude down lower before hitting the ground.
I decided not to go to all this trouble and simply do the math and get the most out of what I had.

I machined 33mm off the length of the Z axis post and removed the post spacer.
I then started making an adjustable ball nut mount. I machined a 30mm thick ronund collar with a 18tpi UNF thread in it to suit the ball nut mounting thread into a piece of 90mm black mild steel. Hopefully I'll finish the mount today.


Chich

chich2
04-01-2007, 06:46 PM
Yesterday I milled a flat onto the side of the mount for the clamping screw. I did this CNC by the way but used manual depth of cut each pass. I drilled and taped the hole for the clamping screwand drilled 3 holes to secure the mount to the post. I drilled and taped the post M6 and bolted the mount to the post. Next I put 3 blades into a hacksaw and cut a big thick slit right through one side of the mount to make it into a big C clamp. This will later secure the ball nuts once I adjust them.

Chich

chich2
04-01-2007, 07:18 PM
The 1" X 1/4" ball screw I have then needed to be attached to the machine solidly and straight. To do this I took an angle grinder and manualy ground of the hardened thread profile from one end of the screw. I put the screw into my 3 jaw in the lathe and set my lathe thread cuting lead screw to 4tpi which is 1/4" I then placed a dial indicator onto the flank of the thread and chased it.... It ran out 0.01 of a millimeter...... Not even half a thousanth of an inch. PRETTY LUCKY I thought so I machined the end of the screw down to 18.02mm diameter with a square sholder before my luck changed.

Instead of re-making a new end for the screw to attach to the machine and having to machine up shoulders and keyways and a thread I decided to simply cut the end off the old original screw and attach it to the ballscrew.
I held the old screw in soft jaws in the vice and took the plunge and cut the end off with a hack saw! OUCH! Befored I did this I had a good long think about what I may need the old screw for before the new screw can go in. Fairly confident I was safe I cut it off.
I put the stub into the 3 Jaw again and thought to myself "there's no way I'm going to be lucky enough to have some thing else run true in a 3 jaw twice in one day but I tried any way. This time the run out was 0.015mm. I loosened the chuck, rotated the job a little and retightened it............... 0.005mm Sweet!!!!!!!! I can definately live with that. So I drilled and bored out the inside of the stub to 18.00mm This gives me 0.02mm intreference.

I put the stub in the vice and heated it up to about 120deg with a LPG blow torch, then quickly droped the screw into it, give it a little hit with a copper hammer and let it cool. Once it cooled down I drilled and taped 2 M6 grubscrews 90degrees apart (on the same flats the pulley drives on) through the stub and into the ballscrew end and secured them tight.

I sat the screw up on V blocks and rotated it under a dial indicator. I measured less than 0.01mm run out using this method.


Chich

chich2
04-01-2007, 07:51 PM
Now it was time to put it all together. I put one ball nut onto the screw by cutting the cable tie off that holds the cardboard cylinder from falling out. I pushed the card board cylinder up against the end of the screw and started screwing the ballnut up until it started on the screw. Once the first nut was on I attachd the mount to it but left the mount overhang the end of the screw. I then cut the cable tie on the second nut and screwed the second nut into the mount being careful not to let the cardboard cylinder come out. Once this was screwed in I then carefully screwed the screw into the second nut and carefully rotated the nuts in the mount until the screw went freely into the second nut and pushed out the cardboard cylinder.
Once both nuts were on the shaft I held the nuts and spun the mount down tight onto the bottom nut. I dont want there to be any movement of the bottom nut during operation. All adjusting is to be done on the top nut.

When it came time to adjust the backlash, here's what you have to be careful of. In this arangement there are 2 diferent thread pitches both sitting along the same axis. One is 4tpi the other is 18tpi Because there is backlash in the 18tpi thread where the nut screws into the mount you have to remember that when the mount is squeezed by the clamping screw the clearance in the 18tpi thread is going to be reduced down to zero. If you have the 2 ball nut 4tpi threads pulling the 2 mounting 18tpi's apart before you do up the clamp screw, the 2 ballnuts get pulled together even further therfore increasing the load you thought you set on the ballscrew.

The way I adjusted mine was screw the 2 nuts apart until I just felt the nuts stop with very light finger pressure. I then backed off the nuts very slightly (to acieve some backlash) and tightened the clamp screw up tight. I then measured for back lash. I kept on repeating this process about another 3 times until I achieved a very slight preload - zero backlash.

I then oiled the thread and stood it upright on the bench. The preload nut assembly is that free that it screws it's way down the screw under it's own weight and has zreo backlash.

I attached the assembly to the post.

I'm thinking of putting a bolt on stopper to the end of the screw so the screw can't be accidently screwed out of the nut and drop balls every where.


Chich

DennisCNC
04-03-2007, 07:33 PM
^ Wounder why you put two nuts on the knee screw? Is the nut load rating low? The weight of the knee should keep all the backlash out if the gibbs are not to tight.

chich2
04-04-2007, 10:50 AM
Dennis,
Thanks for your question. Yes you are right. I did have the gib a little too tight and have adjusted it off a little. The load rating of the nut is fine, I just decided to place 2 nuts this way to eliminate any errors I may encounter if I select the wrong air pressure in my cylinder but you are correct in saying the weight of the knee should do the trick.

I have some more progress to post but it's after midnight at the moment so I'll add some more to the thread tomorrow night.

Chich

chich2
04-07-2007, 05:58 AM
I added a stopper bolt to the bottom of the Z axis ballscrew to prevent the screw from being wound up too high out of the bottom nut and dropping the balls.

Chich

chich2
04-07-2007, 06:34 AM
It was now time to make the new servo motor mount and connect it to the mill. I cnc milled out a piece of 50mm X 50mm box section by manually moving the Z axis.

Once it was all together I made some small adjustments to things like very slightly loosen off the Z gib (I did have it too tight) I did this with a dial indicator to measure the deflection on the knee when the slide locks were done up and then released. I adjusted the Z slide free with zero knee deflection on the dial indicator when locked and unlocked.

When the pressure to the air assisted knee was turned on and set to 50psi I couldn't believe how free the entire knee moved. It works perfectly!!!! :banana:
I can raise and lower the knee with equal ease by turning the Z axis dial WITH MY FINGERS!!!!!! Very happy!!!!!

I have to neaten up the wiring on this axis and then it's finished.


Chich

chich2
04-07-2007, 06:59 AM
The mill now consists of X and Y axis with standard Hafco screws and anti backlash nuts and a Ballscrew air assisted Z axis. The near future will see the X and Y axis's converted to ball screws.

Here is a little video of my first 3 axis CNC milling job EVER! I wrote the G-code by hand and it worked a treat. I only took very light cuts as it was my first job and I didn't want to push my luck. Turned out perfect! The video is of the HM-52 3 axis milling a 'T' nut. When it was finished I put it in the lathe and parted it off.

http://www.youtube.com/watch?v=4vrP2i8SvPU

I made the top 2 in the photo. the bottom one is a sample. It has a stripped thread so I made 2 new ones and blacked them with gun black.

Chich

DennisCNC
04-08-2007, 02:10 PM
Nice!

chich2
04-09-2007, 04:42 PM
Thanks Dennis,
Good work on the duck too I say. You wouldn't be playing with the Rhino tutorials by any chance?

Well Done,
Chich

DennisCNC
04-10-2007, 07:23 PM
Hehe, it was my 12 year old brother that made it from the tutorial!


Dennis

abomination
04-25-2007, 08:58 AM
Excellent work Chich,

Stumbled across your "t" nut video on utube and got very excited to see the mill was a HM52. I've got the HM50. You've set the bar pretty high mind you. I just hope that my conversion works as well as yours. The work you've put into it is astounding.


I think that I'll fit a VFD for the spindle drive 1st. I get sick of changing the drive belt position. Plus, i can buy the drives pretty cheap from Mechtric in brisbane.

As for your comment of adding ball screws to the x and y axis, have you tried TEA Transmissions in queensland. They sell all that kind of hardware, and from what i have bought, the prices have been pretty good.

Like others have said, i will have to read the thread a few more times to cement the ideas in my head.

Again, excellent work

Brad

chich2
04-28-2007, 09:56 AM
Thanks for the kind words Brad.
I had a look at the Variable Speed Drives you recomended and I'm also interested in doing the same. I am VERY interested in converting my horozintal spindle in my HM-52 to a small CNC lathe. Z and X axis for the lathe is simply X and Y of my current mill configuration with tooling bolted directly to the mill table. All that realy needs to be done is set up the software (wihch will be MachTurn) add an encoder to the spindle for thread cuting and VSD the spindle. I aim to replace both standard motors with 2.2kw 3phase to run each spindle. I will place a selector switch between the motors so I can choose which ever spindle I wish to machine from and run that motor from 1 VSD.
I see some of the VSD's they have are capable of - single or 3phase in - to 3 phase out. That would probably be expensive but would give you great flexibality in terms of wether you have 3 phase power or not.
I will give Mechtric a call on Monday and have a bit of a yarn with them I think. Thanks for mentioning their name.

No I didn't know of TEA Transmissions until you recomended them. I'm shure I'll call them if my current ball screws play up.

Thank you for your post and the usefull information you have added.

Chich.

chich2
05-01-2007, 12:16 AM
Today I hopped on the phone and called around for Variable Speed Drives (VSD's). After calling many vendors and manufacturers I ended up following Brad's advice from his previous post and purchased a Delta drive through Mechtric in Brisbane. When it comes time to upgrade the motors on the mill I want to put the biggest motors I can that will still run from the available power a single phase house outlet will supply. It seems all the VSD's that go from single phase to 3 phase all stop at 2.2Kw or 3Hp so I have purchased a 2.2Kw 3Hp drive. The HM-52 comes with a 1.5Kw motor on each spindle so 2.2Kw will be Plenty! I wish to have the machine with spindle braking as well so I purchased a breaking resistor as well. This means that if the spindle is at high revs and it needs to slow down quickly, the excess power is shed off through the resistor and the motor rappidly slows down. This will come to be helpfull when I configure the horizontal spindle to be a small lathe.

The breakout board I have from CNCTeknix has 2 ports on it for spindle controll. They are labled "PWM output for spindle controll 0-5VDC" During my search for VSD's I noticed none of them have an input that reads a PWM of 0-5Volts. The Delta drive does take a 0-5Volt DC input as one of the options but it's not a PWM signal. I talked to Peter at CNCTeknix and he told me to run the wires from the breakout board to the VSD input, place a 1k ohm resistor inline and bridge the 2 wires with a 1uf capacitor as close to the drive as possible.
This will remove the PWM and should give me a 0-5VDC signal. Thanks Peter!

Don at Mechtrics was very helpfull explaining the features of the drive and for the price, it does the same functions as what the competitors drives do but the competitors charge a lot more.I purchased a Delta DEVFD022S21E drive for $467 AU + tax and a DEVBR300W70 braking resistor for $55 AU + tax. Should be here by the end of the week.
Next i'll decide wether to get 2 pole or 4 pole motors and try to pick them up second hand.

I still haven't fitted the ballscrews to the X and Y axis yet but hope to do that soon.

Chich

abomination
05-01-2007, 04:48 AM
Hi Chich,

Glad to hear you had success with Mechtric. I have been dealing with Don for years, he knows his stuff. The Delta drives are great. Have units that have been going for 7 years without a hitch.

Next thing, you can pick up a panel mount digital tachometer for $119 to give you RPM of the spindle. It accepts NPN inputs (i use an inductive proximity sensor $45)so it would be positble to have a changeover switch to alternate between the verticle or horizontal spindle.

As for motors, if you are looking at second hand ones, I have heaps of them. I will have a look tomorrow to see if I have any 2.2Kw capable of 240v / phase to suit the VFD. I have the HM50 so I assume that you are going to mount the motor in the same place and the verticle spindle motor? I'm only asking because of the frame size of the motor and foot or flange mount.

Your mill is turning into quite a beast

Brad

epineh
05-01-2007, 05:55 AM
Interesting price on the VFD Chich, I think I will definately go that way for my spindle, cheap as chips...just have to get the rest of the machine going, lol. At least I will only have one spindle :stickpoke
What was the freight on the VFD ?
I assume you are getting one VFD and switching it between the two motors ? Hang on a minute, I think I just gave myself another job to do (chair)
Russell.

chich2
05-01-2007, 06:29 AM
Brad,
Yes I am going to mount the motors in the same position. This will allow coarse adjustments in spindle speed by making radical pulley changes Eg a low RPM high torque range or a high RPM low torque range. Dont realy know yet but the option is there. I will probably simply run a 2 groove pulley on the motor directly to the spindle pulley. Brad If you do have motors to spare i'd be interested. I have attached 2 photo's of the motors I need. One is a flange mount like yours and the other is a foot mount. I havent decided wich way to go yet wether I get a 4 pole or a 2 pole???? Any sujestions would be great. I'm pretty sure the VSD I have coming has a motor speed read out as one of the display modes the front panel shows. I think it calculates the speed via the frequency it's outputting to the motor. No way as accurate as your set up but probably good enough for me for now.

Russ,
Yes I hope to have a 3 phase selector switch that I can choose between spindles. The freight on the VSD was $27 bucks delivered to the door. If all goes well Ill have it by Friday. And yes I'll need a good electrician to check my wiring when it's done................. Dont know any good ones do you? :stickpoke

Chich

epineh
05-01-2007, 07:00 AM
Ha, no decent ones, just dodgy ones. Might just have to stand outside when we turn it on for the first time :)

Russell.

chich2
05-04-2007, 01:06 AM
Today I got my VSD and breaking resistor from Mechtric in Brisbane. The drive arrived well packed in bubble wrap in it's original sealed packaging. The whole lot was in a freight air bag. I opened it all up to check it out and have added some pictures to this post.

Chich

abomination
05-04-2007, 09:37 AM
hi Chich,

Good to hear the toys have arrived. You'll have to mount an external potentiometer for frequency control to keep the VFD looking pretty and grubby finger away. I use a 20 turn pot making speed adjustment very acurate.

Was flat out this week at work. Had a quick look at my motors but all a little smaller than the 2.2kw you are after. Will have another look on Monday.

As for rpm of the motors, well i guess that depends on the max speed you need from the spindles and the gearing. You can safely run the motors at 60hz via the VFD frequency which gives a few more rpms.

So many choices
Have Fun
Brad

turbostang
05-06-2007, 11:22 PM
Chich - The whole conversion looks great! I am ordering my G3616 tomorrow (same as what you have). I've done a bunch of digging and keep coming back to this thread!

My main question (and what I kept searching for) was the Z axis conversion part - I couldn't decide if I wanted to use the spindle or the knee. It looks like I'll be doing the knee like you did - especially after seeing your thread!

Once I get the machine here I'll be making the parts for the conversion almost immediately. :D

I just can't decide if I want to mount the motors directly to the screws or do it like you did. The direct method takes out the extra moving parts, but it also makes the motors stick out a lot.

I sure like the extra horizontal spindle, but I can't decide if I want to shell out the extra dough to get one - do you use it alot?

Keep us posted on the VFD conversion, I'll probably end up doing that soon too!

chich2
05-07-2007, 02:25 AM
Thanks turbostang.
I am happy I automated the knee rather than the spindle. A qill like my machine is realy only suitable for drilling. The knee is WAY more rigid, has LOADS more travel and further more it's adjustable. On my machine if I had of CNC'd the quill I would have not have been able to fully use my horizontal spindle to it's full potential either. I have done a few manual jobs with the horizontal spindle. A bit of gear cutting, Facing, A lot of roughing because the horizontal spindle is so rigid. As I don't use coolant yet any pocketing I do I do it horizontaly so the chips just fall straight out of the pocket and dont become a problem. (I try to use insert cutters as much as possible).

The main reason I mounted my servo's this way was so I can easily change pulley ratio's if the motors were too weak or if the machine was too slow. At the time I didn't know if the motors I have had enough grunt to drive the screws direct drive, so the pulley option sounded good to me.


Did a search for your G3616. Machine look identical to mine. What can I say? Nice machine!!!!! :D Be prepaired to spend some time on it because it's VERY addictive! Congrad's on your first step. I hope to see a thread on your conversion here at the zone!

Thanks for your post,

Chich

turbostang
05-07-2007, 08:24 AM
Thanks turbostang.
I am happy I automated the knee rather than the spindle. A qill like my machine is realy only suitable for drilling. The knee is WAY more rigid, has LOADS more travel and further more it's adjustable. On my machine if I had of CNC'd the quill I would have not have been able to fully use my horizontal spindle to it's full potential either. I have done a few manual jobs with the horizontal spindle. A bit of gear cutting, Facing, A lot of roughing because the horizontal spindle is so rigid. As I don't use coolant yet any pocketing I do I do it horizontaly so the chips just fall straight out of the pocket and dont become a problem. (I try to use insert cutters as much as possible).

The main reason I mounted my servo's this way was so I can easily change pulley ratio's if the motors were too weak or if the machine was too slow. At the time I didn't know if the motors I have had enough grunt to drive the screws direct drive, so the pulley option sounded good to me.


Did a search for your G3616. Machine look identical to mine. What can I say? Nice machine!!!!! :D Be prepaired to spend some time on it because it's VERY addictive! Congrad's on your first step. I hope to see a thread on your conversion here at the zone!

Thanks for your post,

Chich

That's the exact point I argued with my wife (she's a CNC programmer by trade), the spindle is no where near as rigid as the knee and has no where near the travel.
I like the way the motors are not in the way, but I'm just concerned with longevity etc. I am sure there is no problem, but with my luck - they wouldn't last long, lol.
I am still debating (with myself) on whether or not I need to get the additional spindle or not - I don't know that I'd use it a lot...but one time is enough for me to want it :D
I've been out of the machine shop for quite a few years, about 6 to be exact, I had a ton of fun while there. I started getting the itch to make something and I stumbled on a DIY video... I do a lot of racecar fab work and to be honest, I could have used a mill a long time ago!

chich2
05-07-2007, 08:56 PM
Turbo,
You lucky Bugger!!!! YOUR WIFE IS A CNC PROGRAMMER!!! :banana: How cool is that?????? It even sounds awesome just saying it!!!!! Khaaa Haaa. Your a lucky man!

You should consider the horizontal spindle option very carefully. I am currently in the planning process of converting my horizontal spindle into a very small CNC lathe. The Mill table moves in 2 axis like a late and the splindle spins like a lathe so why not I thought. I have to carefully calculate the strength of the spindle and attachments where I will bolt the chuck to so I dont have a dangerous situation of the chuck breaking off and injuring someone! I could simply CNC convert my lathe but the mill is already done.

Definately convert the Knee!!!!! The only bad pionts I can see so far to converting the knee is that you need to run an air compressor as well as the mill. The compressor I use is a tiny little cheap $200 direct drive 2.5Hp with a 40 Litre tank. It cycles on and off about 8 to 10 times a day to maintain my pressure. The compressor is always a must in a wokshop anyway for air tools and will also come in handy when I make my air drawbar.
You will also need some extra components like a precision air regulator and an air cylinder (preferably with low friction seals but it doesn't realy matter) I operate my mill at 50psi on the regulator. My cylinder is 100mm diameter and has a stroke of about 450mm or 500mm. I can't remember the length of stroke but it's a tiny bit more than my max Z axis travel. Oh the one thing that was a gamble for me was cutting the mill up to fit the cylinder. Not a good engineering moove I know, but I realy don't think cuting it has altered anything very much.

The magnets in my motors on my mill do attract steel chips and swarf a tiny bit and I have always intended to cover the motors so this doesn't happen..... I just havent got to that yet. I have limited room in my shop so my motors mounted the way they are fit in nice and snug.

Chich

turbostang
05-07-2007, 09:04 PM
Turbo,
You lucky Bugger!!!! YOUR WIFE IS A CNC PROGRAMMER!!! :banana: How cool is that?????? It even sounds awesome just saying it!!!!! Khaaa Haaa. Your a lucky man!

You should consider the horizontal spindle option very carefully. I am currently in the planning process of converting my horizontal spindle into a very small CNC lathe. The Mill table moves in 2 axis like a late and the splindle spins like a lathe so why not I thought. I have to carefully calculate the strength of the spindle and attachments where I will bolt the chuck to so I dont have a dangerous situation of the chuck breaking off and injuring someone! I could simply CNC convert my lathe but the mill is already done.

Definately convert the Knee!!!!! The only bad pionts I can see so far to converting the knee is that you need to run an air compressor as well as the mill. The compressor I use is a tiny little cheap $200 direct drive 2.5Hp with a 40 Litre tank. It cycles on and off about 8 to 10 times a day to maintain my pressure. The compressor is always a must in a wokshop anyway for air tools and will also come in handy when I make my air drawbar.
You will also need some extra components like a precision air regulator and an air cylinder (preferably with low friction seals but it doesn't realy matter) I operate my mill at 50psi on the regulator. My cylinder is 100mm diameter and has a stroke of about 450mm or 500mm. I can't remember the length of stroke but it's a tiny bit more than my max Z axis travel. Oh the one thing that was a gamble for me was cutting the mill up to fit the cylinder. Not a good engineering moove I know, but I realy don't think cuting it has altered anything very much.

The magnets in my motors on my mill do attract steel chips and swarf a tiny bit and I have always intended to cover the motors so this doesn't happen..... I just havent got to that yet. I have limited room in my shop so my motors mounted the way they are fit in nice and snug.

Chich

Yup, but she's already said "I'll help a littel bit, but not much"... Ha! So she thinks! I ordered the machine already, I did get the one with the Horizontal spindle as well, not so much for the spindle - but the machine actually is a bit bigger. It adds close to 6" in X and almost 2" in Y, and I think the same for Z. I may never use the horizontal spindle, but the travel will get used often.
I kinda read through the thread a bit, and vaguely remember the air cylinder - How mandatory is it? I mean would a bigger servo take care of it? By the way, what motors are you using (I'll go look in case you posted it, which you probably did, i just don't remember).
It will take me a while to save up for the CNC conversion, I have a TON of tooling to get first.... :( I'll also have to raid the scrap yard a few times in hopes of finding some good drops to make the necessary parts from too.

chich2
05-13-2007, 08:34 AM
I picked up my two new 2.2Kw spindle motors the other day. I got them from Marlin Coast Motor rewinders in Cairns. The motors I got are brand new WEG motors. I got one flange mount and one foot mount. They cost me around $260Au each. (Slightly different prices for the flange and foot mountings)

I also got some more motors off Babinda01 to beef up my X and Y axis servo's if needed. Here's some pix.

Chich

macona
05-13-2007, 12:34 PM
[QUOTE=chich2;294551

(I try to use insert cutters as much as possible).

I have to carefully calculate the strength of the spindle and attachments where I will bolt the chuck to so I dont have a dangerous situation of the chuck breaking off and injuring someone! [/QUOTE]


Unless you are actually pushing carbide to the SFM and feedrates they like to see you could be wasting your money on inserts. Also it is often best to run carbide dry as well unless you have full flood coolant.

You will not break off the chuck. Dont worry. For that matter look in to getting a ER-40 collet holder for your taper. This will cover a good range of sizes and have a whole lot better runout than a 3 jaw. Either way you are going to be limited to stock length since there is no through hole. Unless you are doing a lot of short parts its going to get old.

chich2
05-13-2007, 08:47 PM
Macona,
Thanks for yor reply. Yes all the little jobs I have in mind for the lathe idea on my mill are all very small and do not require a through hole chuck. For long jobs I have thought about placing a live center in the horizontal arbor support (which attaches to the dovetail ram for gear cuting ect) and using it as a tail stock. It will work great for long jobs but I really don't think I'll ever do long or large jobs on the mill in this configuration so i'll probably never make it. I like your sujestion on the colet chuck. I already have a ER-32 chuck and a set of collets up to 20mm so these will definately be used. I agree with you 100% on the coolant subject and I dont use coolant at all on my lathe. I use a squirter bottle on the Mill when I use HSS tools other wise everything is carbide, dry and HOT! As you say, I am not going to come close to running an insert tool even close to it's designed tool loadings on the little lathe idea on the mill. I am a Fitter/Machinist by trade and I already have loads of inserts and tools so tooling isn't a problem. To strengthen what you say however I think the home hobbiest on the other hand shoud firstly use and sharpen HSS tools so they learn correct tool geometry/speeds/feeds ect. I think a true understanding of this area is a must for any one cutting any thing. Insert cutters will give them greater room for error if they get something a bit wrong but this should come a bit later.

Thanks again for your post and valued information Macona. :) How is your mill going by the way? As you will see from my thread I placed an air cylinder to assist the weight of the knee similar to your Supermax. Works perfect.

Thanks
Chich

macona
05-13-2007, 09:25 PM
Its going pretty well. I moved to a Gecko G100 to control everything and it seems to be better. I get 400ipm rapids on x and y and 100 ipm on z. Got the control panel mostly finished in the past two days. Todays project has been making up a pneumatic collet release for the tormach tooling system I use. It will be nice not to have to use a step stool to change a bit.

chich2
05-15-2007, 08:09 PM
Hi everyone,
The other day I recieved a Private Messaage (PM) from Tubostang. Turbo asked some questions that I thought I haven't brushed over very well in this thread so I replied to Tubostang asked for permission to post the PM into the thread. "Please do, post the question, AND the answer!" was what I got back from Turbo so here goes.

Turbostang Wrote:
Hey chich,

I finally got my mill (remember it's the G3617, just like yours). I don't have any tooling to speak of, but I was dying to check it out and see how it cut etc.. I loaded up a scrap piece of aluminum and made a few cuts... it seemed pretty stout... anyways...

I had a question about your air cylinder - is it a double action? I've found a few different ones on ebay but they all seem to be dual action. The one I am looking at has a 19 5/8" stroke though, which is a bit longer than what you have.. not sure on the OAL, but do you think it will fit or will it be too long?

I read your post about 500 times it seems like and don't remember seeing anything about what torque your motors are.. what are they?

If you could do it again, would you get stronger motors or maybe more gear reduction? Where did you get the gears at anyways? I'll probably get some ballscrews as soon as I start the conversion, I don't want to deal with the ACME backlash problems :(.

Is there any reason you put the X axis motor on the RH side of the table? I was just curious, I'm right handed and having the motor on the LH side of the table, out of the way would be nice.

I'm going to start my CNC conversion soon but I wanted to pick your brain first :)

Sorry for all of the questions Chich!

-Brooks
p.s. Get some new videos up!

I then Replied:

Brooks,
Congratulations on your new mill!!!!! Once you get started you won't stop! Well done!

No problem with all the questions..... That's why we are here! I'll try to answer all your questions one by one.
When I do all my milling with the verticle spindle I do the following to make it as rigid as possible.
1. engauge the fine feed on the quill so the little hand wheel can be used.
2. using the hand wheel, wind the quill right up hard into the head.
3. when it's tight, lock the quill lock.
4. Take all your depths of cut by raising the knee. Remember the quill is realy only suited for drilling.
This will make the verticle spindle nice and rigid.

Yes my cylinder is double acting but I only use it single acting. I simply let the top port vent to atmosphere with a little gause strainer over it to stop anything going in there. I just went and measured the cylinder. It is 4" in diameter and the cylinder tube (body) is 20" long. The cylinder has more travel than my Z axis. My total Z travel is 12 1/2" long. This is not due to anything to do with the air cylinder though. The max length of Z travel is dictated by 2 things.
1. How long the lead screw can be without hitting the ground (the floor the mill is standing on) when the knee is fully lowered. (note: this determines the max length of thread you can use).
2. The max height the knee can go up without the end of the ball screw comming out of the ball nut and dropping the balls when the knee is fully raised.

You can get better travel than this if you place your mill on a stand and get your mill up off the floor a bit therefore giving you the oportunity to make your screw longer and in turn give you more travel. I was happy with 12 1/2" so left my mill on the ground.

Just to go off the topic for a moment. My mill has the following CNC travell dimensions:
In relation to the Verticle spindle X = 22" (560mm) Y = 9" (230mm) Z = 12 1/2 (315mm)
In relation to the Horizontal Spindle X = 22" (560mm) Y = 12 1/2 (315mm) Z = 9" (230mm)

Your 19 5/8" stroke is only a little longer than what I have. It is probably OK. Try not to get a cylinder that has welded on or screwed on ends. Try and get a "tie rod cylinder" That is one that has 4 realy long bolts running up the outside of it along it's entire length. This way you can very easily make the cylinder shorter if it doesn't fit. All you do is unbolt it all, Machine the cylinder tube shorter, put it all back together.

Information on my original motors I used was from a CNC serviceman who from dealing with servo's a lot thought they'd be good enough to do the job. For X and Y they are only just good enough but they lack enough poles and windings to make them really good. They work...... But there's better. The bloke has actually given me bigger ones. I don't know how much torque they exert but it's certainly more than I need so I'll fit them shortly. As a comparison the old motor dimensions are 3"dia 6"long the new motor I put on the Z is 4"dia 8" long. When pulled apart there is odvious difference straight away. More of everything in the bigger motor.

To answer your next question which is kind of in the answer above. Yes I would use bigger motors If I did it again...... I am actually in the process of doing it again now and setting up to put the same size motor on X and Y as what I currently have on Z. These bigger motors (the brown ones in my previous pictures) have 4 brushes instead of 2. This means more torque which may one day lead me to changing my pulleys to make the mill rapid faster.

Definately get ballscrews straight up!!!!! The time I spent with the ACME thread and backlash is no where near the cost and ease of ball screws. Shop around and get them. You can save a bit of $ by machining up stubs to go on the end of the screws so you dont have to machine off heaps of valuable thread. Just be thourough with your machining and run out.

My servo grooved pulleys are from "Gates" I just purchased them from my local bearing suplier. I have made grooved pulleys for different things as stated somewhere else in this thread but small ones like the XL series are much cheaper to buy straight off the shelf.

The reasons for mounting the servo on the right is because the standard Hafco auto feed unit was on the right side so I just took it off and mounted my drive there. The other reason is that the thrust bearings and adjustment for the X axis screw is on the left so another reason I mounted it on the right. I left all the standard X axis thrust bearing arangement on the machine.

I thought i'd still reach for the hand wheels all the time once I had converted the mill over but when I make the new brackets for the new motors I don't know if I'll add hand wheels. I simply dont use them any more! Seems the first thing I grab for tis the keyboard! Actually I probably will have at least 1 hand wheel per axis. This will be for someone like my brother inlaw, who isn't fimaliar with CNC. This way if he needs to drill or mill something, he can still use the machine.

Hope this has answered your questions,
I know I havent realy told you the ratings of my motors but that is info I simply don't have handy. I could get it if you REALLY REALLY........ REALLY want it.

Oh yea... I will get some new Video's comming.

Have fun with your new mill.
Chich.

turbostang
05-15-2007, 09:13 PM
Chich -

Thanks for taking the time to reply, it helped TONS! - What ratio did you use on the pulley setup?

Once I get some of the parts gathered up, I'll make my own thread and post progress.

I'll probably be bugging you much more in the future in regards to the VSD and other things, I'm totally lost when it comes to electronics (I have to get kits to get what I want!)

turbostang
05-15-2007, 11:02 PM
I did some more reading in your post and I finally found where you said it had a 14T motor pulley, but I couldn't find the big lead screw pulley. It looks to be about 60T - correct?

So... would that make it 4.28:1?

chich2
05-16-2007, 08:53 AM
Turbo,
You are close in the pulley sizes. I use 14 tooth on the motor and 56 tooth on the lead screw. This gives me 4:1 reduction. I'll be keen to see your thread. Bug me all you like for info. I'll try to help as much as I can.

Chich

chich2
05-16-2007, 11:10 AM
Well I finally made a start on mounting my X axis ball screw. Pitty I satrted doing this on my last day of my holidays!! Off to work tomorrow so no more progress for another week.
I measured everything up, Cut the material, and milled it to size. I oxy cut a piece of solid mild steel and milled it to 58mm X 62mm X 230mm.

Here is a Video of it being roughed out.
http://www.youtube.com/watch?v=9jU-DpH4IfM
These are 1mm cuts. The mill has no problem doing this but is under a fair load.

Here is a video of the end being milled in the Horizontal Spindle.
http://www.youtube.com/watch?v=VJukysciYNk
All I did was put the cutter in the horizontal spindle and swing the vice 90Deg.

Here are some before and after shots.


Chich

turbostang
05-16-2007, 11:20 AM
Chich - Looks good!

I think I found some motors for mine - 1100 oz. Servos, for a good deal! I'll probably use the gear reduction on the Z axis for sure, and maybe not quite as much as you did on the X and Y axes. I want the Z to have as much help as it can, since the knee is soooo heavy.

chich2
05-16-2007, 07:29 PM
Turbo,
Are you going to add an air cylinder to your knee? If so I believe you could go faster tah 4:1. The effort requred to raise and lower the knee on my mill is a tiny bit more than the X and Y axis...... That's not much! I can raise and lower my knee by turning the graduated dial on the Z with my hand! There really is very little effort. I don't know how strong your servo's are. Perhaps try 4:1 as a starting point. I use XL series belts 3/8 wide.


Chich

turbostang
05-16-2007, 10:27 PM
I'll probably add a small air cylinder. I like the added insurance of keeping the servos happy! I talked to Marris today (from Gecko). That guy is a genious. He helped me with pulley sizing, power supply demands, gecko drives...you name it - he had all of the answers. Once my motors arrive, I'll verify they are what I ordered. Once I verify them I am calling Marris back to order the gecko drives and maybe the power supply as well. Marris went on to say that the motor is plenty strong enough to lift the knee on it's own, especially with the gear reduction.

In the next week or two I'll be starting my own thread, I can't wait - I feel like a kid in a candy store!

chich2
05-29-2007, 09:27 AM
I FINALLY got some time to do some more on my mill today so I did a bit more on fitting the X axis ballscrew. I made a new mount to hold 2 ball nuts. The new mount goes on where I made the first anti-backlsah nut assambly. The new mount works exactly the same way my Z axis mount works.... once the ballnuts are preloaded, I do up the clamping screw to lock the nuts in place. You can see the clamp screw underneath. Here are some pix. Oh the last one is of Bill, my trusty but mostly sleepy Apprentice! Thought it was a funny photo so I thought I'd throw it in.

Chich.

turbostang
05-29-2007, 09:46 AM
Chich - how much movement are you losing in X? about 1.5"?? I guess that and the price is the only real drawback to the a/b nut assembly?

davo727
05-29-2007, 12:10 PM
Hey Chich, Very nice X ballnut mount . Thanks for sharing. I had been contemplating a double nut mount for the X on my rf45. I like the clamping action on yours , it eliminates having to thread the mount. Dave

chich2
05-29-2007, 08:30 PM
Turbo,
Very sharp pick up! Would you believe that I don't loose any X travel at all? When I designed this I made sure that the new arangement would not be at the cost of travel distance. You will see in the second last lot of photo's (post #139) a long solid block of steel sitting beside a coke can. This block is a spacer and it will bolt to the table. What it does is space the lead screw mount and servo mount out 60mm from where it used to be. This way the entire assembly is offset by the amount that the ballnut assembly takes up. There is also a 5mm gap on the end for safety so you could say that I actually gained 5mm of travell. I wont be using this 5mm. It's only so that there's a gap between the screw parts and when the mechanical stops on the slide touch.

davo727,
Thanks mate! Welcome aboard! :)

turbostang
05-29-2007, 09:29 PM
Makes sense! Good job!

I finally got some of my cutters in today. There should be a couple more coming tomorrow, along with my air cylinder.

We are moving into a new house, actually we are having one built, so my mill conversion will probably be on hold. Unless we get a rent house, then I can still work. I am just dreading moving that machine 2 more times. :(

Ron111
05-30-2007, 09:26 AM
TURBOSTANG,
Could you give some details of your air cyclinder, where you got it and general spec's.

Thanks

Ron

turbostang
05-30-2007, 09:39 AM
TURBOSTANG,
Could you give some details of your air cyclinder, where you got it and general spec's.

Thanks

Ron


It's nearly identical to Chich's setup. I got it off of ebay. If you search for pneumatic cylinder under business and industrial you'll find a ton of them. I've seen them for as little as 60$ and as much as 400$. I got mine for 80$ brand new. ;)

davo727
05-30-2007, 10:45 AM
Hey Ron, Just figure out how much travel you need and overall length that will work for you and find a cylinder with about a 2.5 to 3.5 inch bore. I got a 3.25 in bore and 21 in stroke for my rf45 off ebay $50.00 to the house. Dave

chich2
06-01-2007, 06:59 AM
Before I came back to work I finished my X axis ballscrew. This was done by measuring everything up then I ground through the hard surface of the ball screw with a bench grinder. I then mounted the screw in the lathe and machined one end to fit the grooved pulley and steady bearing. Because the other end of the screw has a long parallel section that the thrust bearings load up on and the hand wheel goes on, I decided when I purchased my ballscrews, to make a stub to go on the end rather than pay for 150mm of ballscrew that I would simply grind off and machine. Insted of making this stub I simply cut the required length off the old standard Hafco leadscrew and fitted it to the ballscrew. I machined a heavy interference fit for the 2 parts, Heated the socket part up real hot and quickly bashed it on until it was home. Finished up nice and straight. Here are some pix.

Chich

turbostang
06-01-2007, 09:11 AM
Nice work Chich, You have some good ideas!

chich2
06-01-2007, 05:00 PM
Thanks mate! How's work on your machine going?

turbostang
06-01-2007, 05:10 PM
I haven't touched it as far as the conversion is concerned. I did get some new cutters and stuff finally, but that is about it. My pneumatic cylinder arrived as well, but it got mixed up with someone elses and I have to send it back to get the right one. I also got the servos, Next is the controller etc.

ozzie34231
06-02-2007, 11:28 AM
Chich,
Your X axis nut mount is a touch of brilliance. I'll be using it on my IH build. I used the double nut, screwed into a carrier on my old Shoptask and I measure backlash between 0 and .001".
I've been wrestling with the idea of buying a ground screw for the IH because a new rolled ballscrew has some bumps that wear down and needs some nut adjustment, but removing the table to make that adjustment is a bear of a job. With your mount I'll be able to make that adjustment without taking the table off. Brilliant!!
You just saved me quite a few hundred bucks.
(I was lucky to find cheap ground screws for my Y and Z with double nuts.)
Ozzie

chich2
06-03-2007, 08:16 AM
Thanks Ozzie,
I made sure the nut that's on the inside is up firm against the mounting plate. This way when I release the clamping screw, the only nut that needs to be rotated for tensioning is the outside one. The bearing you see sitting on the end of the screw is the steady bearing that holds the screw on axis. This bearing takes the small radial load created by the drive belt being tentioned. The other end of the screw is the one that holds the standard Hafco thrust bearings.

Chich

ozzie34231
06-03-2007, 04:33 PM
Yes, I like that arrangement, pulley opposite thrust bearing side. Of course it's not possible on the Y and Z where I'll only have support on one end of the screws.
Another thing I like about your setup is that I'll be able to position the nut mounting plate after aligning everything else on the X.
I'll start by aligning the bare ballscrew and its end plates, with bearings, on the inverted table. After I'm happy that the screw is in alignment with the dovetails, I'll pin the end plates. Then I can disassemble, install the table, snug the gibbs get the screw with nuts back in, tighten the end plates, and then position the nut mounting plate. I'll bolt it in place, test it, and then pin it.
If I'm picturing all this correctly, that sequence should give near perfect alignment of all the components. And I suspect less than a thou. backlash.
Ozzie

chich2
06-03-2007, 11:48 PM
Please read next post.......
Does anyone know how to delete a post? I accidently saved this one twice! :confused:

chich2
06-03-2007, 11:51 PM
Ozzie,
Sounds like you have a good grip on what is needed to line it all up. Yes you will have very little back lash and the hand wheels will turn super free! The big diference I found in adjusting the ballnuts compared to loading 2 plain nuts is that the ballscrew can be quite "springy" in thier adjustment. It's not the screw flexing, it's the nuts loading up. What I mean by this is I locked my X axis slide clamp and put a light force on the handwheel. The screw turns a little but no slide movement! This is bad. Because the ballnuts are SO friction free, you can actually load them up a fair bit before you get any slide movement and they'll spring back (this is with the slide lock still done up don't forget). A plain nut setup however has that much friction in the nut that this does not happen. You feel when you are hard up against the backlash with plain nuts as the hand wheel comes to a dead stop. The ballnut you dont feel this. It's just a smooth exponential increase in resistance. I have my ballnuts slightly preloaded so that they are carrying a slight load all the time. Over tightening them will lead to an early death so don't over do it!!!

I'm guessing here but I think that if ever there is positional error on a job being machined, I don't think it will be from incorrect rotation of the lead screw, I think it will be from cutting forces holding more load on the ballnuts and not allowing the table to moove. This error will be very little because of the mechanical advantage you get from a screw AND above all, this is why we take finishing cuts with little load to get something to size.

Ozzie, I just had a look at your IH thread. Do you have any photo's of your build?

Thanks for your post.
Chich

ozzie34231
06-04-2007, 01:51 PM
No pics yet, most of the progress is mental. I started welding the table and then went to Aleuthera for a long week. Now that I'm home the C drive on my main computer is failing. I'm sitting here surfing this computer while the new hard drive is formatting, but no shop work today; need to reinstall about 40 programs.
I will document with photos, probably start a new thread, but the progress will be slow, too much else to get done.

My personal preferance is no handwheels. As for measuring resistance, my amp meter shows me enough. I think to really get to know CNC one needs to abandon all hand control. Joysticks, buttons, MPG's, give more than enough options for moving axis. I really didn't get into it all until the itteration of my Shoptask that included throwing the hand controls away.

I need to be on constant look out for errors. I've had thrust bearings come loose, wear out; pulleys come loose; spring loaded nuts stop spinging; gibbs go out of adjustment; electrical contacts corrode; etc,etc,etc.
And so I measure all the time, every piece.

You're right about hard mounted double ball nuts. The only error I've had there is, as I said, after early use on new screws they need to be adjusted, and once I had a dirt problem. By the way, hot glue wipers absolutely work great!

Did you buy a tap or cut the nut thread carrier on a lathe?
Ozzie

chich2
06-06-2007, 01:32 AM
Ozzie,
Hot glue seals!!!! What an awesome Idea!!!!! How do you make them? Do you lightly oil the thread and then just squirt the glue on? Are different glues better than others? Does the glue ever get injested into the nut? Do you enclose the glue into a holder so it doesn't rotate with the thread?
Good work mate! I reckon I'll be having a go at that!

Yes I machined the thread on my lathe. It is 18tpi with a minor diameter of about 38mm from memory. While the job was still in the 4 jaw I faced the front so that the thread was perpendicular to the face of the plate. This face is the side that I bolted to the mill.

Cheers
Chich

chich2
06-14-2007, 07:32 AM
I got some time to finish my X axis ball screw assembly. I set the preload on the ballnuts and locked them in position. Next the 62mm spacer went on and then the ballscrew steady plate and bearing. After that was to put the servo mount back on and adjust the belt.

Here's some pix,

Chich

davo727
06-14-2007, 11:45 PM
That looks awesome Chich, Thanks for sharing the pics. I just got the servos for my rf45 and im ready to start cutting some metal for ballscrew, ballnut and bearing mounts. I may borrow a variation of your X ballnut mount. Its cool how it gets the nuts out from under the table where you can get at them. Later, Dave

chich2
06-17-2007, 06:28 AM
I was out shopping the other day and purchased a wireless gamepad to use as a pendant on my mill. The game pad takes one AA battery, has a green symbol to show you it's turned on, the green light turns yellow when the battery runs down, and auto power off until you press a button. I had to go to the manufactures site and download the software and updated drivers for it. Once installed the controller has a key mapper program which you use to program the controller to map to any keypress or series of keypresses from your keyboard. For instance you can program one of the buttons as lets say "A" So every time you press that programmed button it's just like pressing "A" on your PC keyboard. Cool thing is it will do a HEAP of characters at once off one press of one button on the gamepad. For example you can assign button no. 1 to type out - Shift+H then e then l then l then o. If I then press button 1 I get "Hello" Pretty cool huh!
But wait! there's more! The gamepad has a key like capslock on your PC which when pressed gives you the abbility to make an entire parallel set of keystrokes for the same gamepad buttons. You can even write macro's and save them to a keystroke on the gamepad. I love it!!!!

The gamepad is a P2900 by Saitek. Attached is a picture of the controller, the USB transmitter/reciever and packaging.

Here is a video of when I first got it going. The first part of the Video is showing how the controller can cycle start my mill and run a loaded G-code. The code in this instance is running my mill through full travel of all axis's at once. The second part of the video is of me jogging the mill about with the gamepad controller.
Here's the video. http://www.youtube.com/watch?v=hhvd6rLctOI

Hope you all enjoy it!

By the way, thanks for your post Dave!


Chich

epineh
06-17-2007, 07:06 AM
Cool Chich !!! now you just need a fire button :D

Russell.

ozzie34231
06-17-2007, 07:34 AM
Oil the thread, clean the end of the nut with thinner, turn the screw so you get to an oiled place, shoot a continous stream of hot glue around the junction of screw and nut. I used the cheapest hardware store stick. Mine work great, stayed in place 6 months or more, don't know how long they'll last.

Next time I have it all apart I'll grind some radial grooves in the nut end, although they're holding fine just the way they are.

Ozzie

chich2
06-24-2007, 08:55 AM
Good one fellas! Thanks for the hot glue tips Ozzie.
Russ, I've been looking for the slot to put the coins in?????


Today I started work on converting my Y axis to ball screw. I removed the entire X axis assembly by releasing the 4 bolts on my swivel table and lifting it with the floor jib crane as can be seen in photo 1. Next was to remove the Y axis servo, mount, and leadscrew. After that I took all the measurements and decided on a plan of action. I have decided to try and increase the maximum travel of my Y axis to as much as I can possibly get. My measurements show that when the Y slide goes all the way towards the column, the new Ball nut assembly will bottom out before the slide comes to the end of travel. This is because the double ball nut assembly is longer that the preload nut assembly I had in there before. I would stand to loose 15mm of travel in that direction. The ball nut itself will touch the mount I made, that the Air cylinder rod pushes on to help lift the weight of the knee. The way this cylinder rod mount is made I cannot afford to cut 15mm away from it or it will become too weak and may flex or bend. On studying the ball nut I found that the section that the balls run inside in the nut is only relatively short and there is a lot of screw inside the nut that doesn't actually do anything. First thing I thought was "cut it off". So that what I did. I measured how much of the nut I could cut off and then disassembled a new ball nut into a clean container. My scriber would not mark the hardened ball nut so I had to paint a line with a yellow paint pen and then scribe the line in that. I then put the ball nut body in the vice and cut off the extra with a 1mm thick abrasive cutting disk in a 100mm angle grinder. I faced off the end to lenght in a 4 Jaw in the lathe and then gave the nut a very thorough clean. I put the nut back together and oiled it up.

Following making the nut shorter I removed the cylinder rod mount and started to cut the remainder of the required material away form it. More on that tomorrow.
Out of the 15mm I need, I got 9mm by cutting the ball nut shorter and I only need to remove 6mm from the cylinder mount and I'm back to full stroke.



Chich

chich2
07-11-2007, 09:08 AM
Did a bit more on my Y axis this week. Took a chunk of mild steel and machined it into a mount for my double ballnut's. I pulled apart the second ballnut and cut it shorter like the one in the previous post.

Here are some Pictures.


Chich

chich2
07-24-2007, 07:51 AM
On the weekend I machined the end of my Y axis ball screw for a press fit onto the stub that will take the preload bearings and servo pulley. I have extended the shaft so that the pulley and bearings will stick out about 70mm further than they used to. This will allow my Y axis to travel out another 55mm allong the knee. I know it's not a good idea but I've made the Y axis over extend the knee by 45mm. This increases my Y travel a lot. It will come at the cost of rigidity but I want the length of stroke more.
Because the Y slide will now go out further it will hit my servo mount. To combat this I have made a solid steel block spacer (similar to my X axis) to moove the entire bearing housing arangement out 68mm. The following pictures show the ballscrew and stub and also the machining of the 68mm thick spacer.

Chich

chich2
07-25-2007, 10:26 AM
Tonight I finished my Y axis ballscrew conversion. I drilled the clearence holes in the spacer block and put it all together. I'm not compleatley happy with the way it turned out. The reason is when I turn the hand wheel I can hear the balls clicking in the ballnuts and I get a small amount of resistance each click. I think it's because I have the return tubes facing downwards and the balls aren't free flowing in and out of the tubes. I can rotate the nuts 90Deg so the return tubes are on the side and see if that helps.

Once it was all together I had to set up the motor controll and do the Math for the different pitch thread I now have and swap the direction of rotation as I standardised an used right hand screw instead of the left hand thread in the standard Hafco arangement.

Here are some pictures of the finished product. Once again, hover your mouse pointer over the picture for a breif description.

Chich

epineh
07-28-2007, 03:10 AM
Nice work Chich (as always), so when do you start CNC'ing your lathe ? :)


when I turn the hand wheel I can hear the balls clicking in the ballnuts and I get a small amount of resistance each click. Chich

Be careful, you MUST look after your balls :D

Russell.

chich2
07-28-2007, 06:42 AM
Thanks Russ!
I don't actually have any plans for converting my lathe. BUT..... I am almost ready to convert my horizontal spindle on the mill to a "mini" cnc Lathe. I have all the hardware to do it except for the spindle encoder which only needs to be 1 pulse per rev. The chuck will be the 125mm 4 Jaw I mounted to my dividing head. Here is a picture of it in the box and also on my dividing head.

Chich

IJ.
09-14-2007, 08:41 PM
Chich: Well done I used a HM50 to make all the parts for my retrofit :)
(considered a 52 at the time but limited room to swing here)

chich2
10-17-2007, 08:40 AM
Hello fellow Zoner's,
It's been a very long time since I have posted on this thread and thought it would be a good idea to add a bit of an update.
Not a real lot has been happening on my mill since last post. I have had a lot on lately and have had no time to continue with my mill.

Below is a problem I have encountered with my mill and Z axis. I continiously had an error of 0.3mm in Z travel every time I went Z- to Z+. At first I thought it to be that spring action in my ballscrew that I posted about earlier. I preloaded the ballnuts a little more..... Made no difference. Then I thought it was bind up in the slides but it wasn't that either.

Then I noticed the verticle column was rocking on the mill base!!!!
As can be seen in the first 2 photo's.

I have since then been very busy fixing this. The first thing I tried was to seperate the 2 surfaces and clean them up, then add an epoxy filler between the 2 cleaned faces and bolt it up all tight again. (Second 2 Photo's)
Worked OK but not good enough to my liking.

I have since compleatly seperated the 2 segments and scraped the surfaces true using a 16mm thick piece of glass and bearing blue. They were both out a long way.

It's getting a bit late at the moment so I will post some photo's of that tomorrow.

Happy to be back.
Chich

P.S. Thanks IJ ! The HM 50 is almost identical to the 52. There seems to be no limit to what you can do with these machines. I hope you enjoy it.

oliomio
10-21-2007, 05:05 PM
Hello Chich2,
This is an inspiring thread, and I thank you for sharing your experiences. I found your photos of the innards of the HM52 fascinating. Having read your experiences I intend to make some mods to my HM52, including the Z gib retainer, and the X axis anti backlash split nut.
I have installed a 3 axis DRO on my machine, and that has led to a huge leap in the capabilities of the HM52.
Your CNC conversion problem solving has been a riveting read, but I think that it looks beyond my capabiities.
Please keep up the posts. I bet that you have other projects which would also be of interest to others. Thanks again.

Oliomio.

chich2
10-28-2007, 09:55 PM
Oliomio,
Thanks for your post. I see you are a first time poster... Welcome to CNCZone. "hapana basa" here at CNCZone has a HM-50 with a 3 axis DRO I have had a fiddle with and I find it an excellent addition to the machine. Well Done!

By the way, I no longer need my X axis anti backlash mount and plain nut any more. I have the assembly just sitting in my cupboard doing nothing. Would you be interested in purchasing them?

Chich

chich2
10-28-2007, 10:21 PM
Well I said I was going to post some pictures about scraping the mating faces of my mill base and column flat and I havent got around to it so here they are.

Firstly to gain some head height I removed my vertical spindle drive motor and pivoted the head over to reveal the dovetail ram. I then borowed a friends Backhoe and rigged it to the mill. I unbolted the Z axis ball screw column form the base, removed the coolant pump and tied it to column and unbolted the base of the mill from the column. It was then a simple operation of lifting the mill up and sliding the base out of the way. I then secured the mill on some timber with ropes and detached it from the backhoe.



More Pix to come,
Chich.

chich2
10-29-2007, 08:38 AM
A week ago I seperated the mill column from the base as per my last post. At the same time I started surfacing the mill base. I firstly took a file and rubbed the surface of the base to find that it had a huge lip of iron running along the entire inside front edge of the hole in the middle. I have marked the area in the first photo where it was high. The epoxy filler that I had added was very thick in the joint as the high spot was keeping the faces apart to form the thick gap. You can see in the first photo all the ridges in the surface.
The second photo shows the bearing blue deposit after wiping over it with a surface plate. In this case a 16mm thick piece of glass. Note there was no contact on the left side at all. I had to remove lots of material on the other 3 sides to get them down as low as the left side before blue became visible.
The third photo is of further progress. A little too much blue I know but you get the idea. Same with Photo 4.

Photo 5 is of the finished product. I know there is way too much bearing blue on this. It's the only way I could get it to show up on the photo. The real thing with the correct amount of blue is as good as this.

The entire surface took 1 and a half days to complete. Firstly I filed off as much as possibe. Then I took to all the high spots found with the glass and took them off with a Burr grinder and a flapper wheel. Pretty aggressive! As can be seen in photo 6. After that I scraped and scraped and scraped but found a MUCH more efficient way was actually to hone the high spots down with an oil stone. I was suprised by how much material the stone took off and it did a great job of flatening the surface far beyond what I could have done with a scraper in the same time. The results from the stone were fast and unbelieveably flat!!!

More to come,
Chich

chich2
10-29-2007, 09:06 PM
Since I borrowed the backhoe I had to return it - So I rolled my mill over onto it's side and sat it down onto timber blocks and rubber. This was easily done with the backhoe and a comealong (wire rope or chain ratchet) tied around the table with a soft fabric sling and conected back to the backhoe out rigger. Then I blued the bottom to find that I still have a lot of work ahead of me. Ah well.... It's all part of the fun and this entire CNC conversion has got me using hand skills I havent used in a long time. Here's some more pix.

This was all done 2 weeks ago and I havent returned to finish it off yet but I will soon.

Chich

hdj80
11-10-2007, 11:33 PM
Hi Chich,

Glad to hear you had success with Mechtric. I have been dealing with Don for years, he knows his stuff. The Delta drives are great. Have units that have been going for 7 years without a hitch.

Next thing, you can pick up a panel mount digital tachometer for $119 to give you RPM of the spindle. It accepts NPN inputs (i use an inductive proximity sensor $45)so it would be positble to have a changeover switch to alternate between the verticle or horizontal spindle.

As for motors, if you are looking at second hand ones, I have heaps of them. I will have a look tomorrow to see if I have any 2.2Kw capable of 240v / phase to suit the VFD. I have the HM50 so I assume that you are going to mount the motor in the same place and the verticle spindle motor? I'm only asking because of the frame size of the motor and foot or flange mount.

Your mill is turning into quite a beast

Brad

Brad

I'm chasing a 3ph foot mount .75Kw something higher than 1500rpm (2800 would be great). Want to VFD convert my 1ph lathe.
I'm in Bris as well.
hdj80@netspace.net.au

Cheers
Craig

chich2
11-18-2007, 09:44 PM
Over the weekend I borrowed a magnetic based drill (photo 2) and drilled 4 new holes into the bottom of the column. I made the holes the same diameter as the original 4. The holes are a clearence size for a M16 x 2mm bolt. The standard size that was drilled for the original 4 hold down bolts is a whopping 18mm hole. I drilled my 4 new holes out to 18mm as well because I am making a tool that will slide neatly inside the hole that will machine the opposite inside face of the flange flat so the head of the bolt will seat nice and flat. Get what I Mean???? :confused: I will show photo's in post's to come.

After drilling the holes in the column I then drilled and tapped 4 mating holes in the base M16 x 2mm. Hopefully when I get the backhoe again my bolt holes will line up. I think they will because I made a paper template of the holes in the column and transferred that to the base so fingers crossed it should all be good.

I have purchased new bolts to go into the base. The 4 standard bolts were grade 4.8 or something like that.
The 4 new Hex head ones I got to replace the originals with are Grade 10.2
The 4 new Bolts I got to go into the new holes I have drilled are grade 12.9 socket head cap screws. I chose cap screws because the heads are MUCH smaller that a normal hex head and this allows me to get the head right up against the inside wall of the column - therefore more leverage or purchase over the clamping area.

Here's some Pix

chich2
11-19-2007, 08:34 AM
As mentioned in my previous post, I wanted to make the head of the new bolts I am going to add, sit flat against the mill column base flange. To do this I made a small boaring bar to be a neat fit in the new holes. This boaring bar holds a small piece of 1/4 tool steel. The boaring bar gets put into the hole from inside the column and pokes out through the side I just blued flat. On the free end of the boring bar goes a thrust plate that has 2 M6 cap screws in it which are used as my feed mechanism. A thrust bearing goes on next (a left over from the Z axis retrofit) followed by the thrust arbor.

The idea is that I use my pistol drill to spin the boaring bar. The boaring bar is a neat fit in the hole so it spins rigid in the hole. The thrust washer is up against the thrust plate so as I screw the M6 cap screws, it pulls the boring bar axialy throught the hole and the uneven casting around the hole get's machined flat.

Here are some pix.
More to come,
Chich

chich2
11-19-2007, 08:55 AM
Following on from my previous post here are some pictures of how the assembly works. I call this my first attempt because it actually only worked once!! When I machined a hole, the tool steel would be blunt!!! I have also encountered this when I first started out scraping the base plate a few weeks ago. My tooling kept getting blunt!!! Files, Scrapers, the lot!! I even hardened my scraper and tried again but the casting still bluntend it very quickly. The other problem I found was in the choice of bearing I used. Because nothing holds this type of bearing together when there is no load on it, there's nothing stoping the two races moving apart allowing the ball cage drop down onto the boaring bar.

See next post for the final assembly.

Chich

chich2
11-19-2007, 09:08 AM
To remedy both of these problems in the previous post, I made a new boring bar but this one holds a cemented carbide turning insert. The bearing problem was resolved by using a different bearing. In this case a simple deep groove ball.

It works extreeeeeeemly well.

Hover your mouse over the thumbnail for a description.

Chich

philbert
11-20-2007, 10:45 PM
Slightly off topic, but I'd love to have chich2's headroom (and a backhoe) when taking a HM-52 apart ;)

I had to remove the spindle and then the ram using my engine crane - sliding that thing out of the dovetail is not fun :(

By the way, it's sitting on (well, just above) a heavy duty trolley made to manoeuvre the thing into position inside my garage (or 'car hole' if you like ;))

davo727
11-20-2007, 11:58 PM
Hi Chich, Nice work!! Thanks for the description on the reverse- inside the hole boring and facing tool. I will keep that idea for future reference, I think I have an application for it coming up soon. Have a good one and keep up the good work :)

chich2
11-21-2007, 04:46 AM
Phill,
Welcome to CNCZone!!!! Good to see you posting. I had a look at your thread in the general discussion forum but sory to say I don't have an answer.
Good luck.

Thanks davo,
You have to start off lightly and then lay into it once you get full tool contact right the way round the hole. I broke one insert going a bit crazy to start off. Once you have tool contact all the way round you can increase the feed quite a bit.

Lucky for me I was using old inserts that still had good edges allong the sides but the points were worn.

Chich

chich2
11-21-2007, 05:34 AM
Today I removed the standard single phase 1.5Kw motor that drives the Horizontal spindle. It was nice and easy doing it while the mill was laying on it's side. I took the new 2.2Kw 3 Phase Motor out of the box that I purchased some time ago and sat it inside the column where the standard motor came from. It will fit perfectly. I might have to make a base plate to bolt it to because the bolt patern is bigger to the standard motor. The pulleys will line up too with the fan cowl almost touching the inside of the column cast webings.

Next thing to do was remove all the old standard motor wiring and controll box. The controll box contains all the breakers and current overloads and interlocks to make the mill run with the standard single phase motors. Most of this will not be needed for 3 phase retrofit so off it comes.

After all this was done I reverse boared the original hold down bolt holes to flaten them up a bit. As can be seen by the last photo.

Chich

chich2
11-24-2007, 10:29 AM
Hello Again,
The other day I thought it would be easier to mount the new horizontal spindle 2.2Kw motor into the column while the machine is still sittng on it's side. I marked out the bolt patern and drilled and taped the holes in the base. I only did 3 holes as the 4th hole will be hard to reach.

The motor is a neat fit into the column. So neat that you cannot open the Junction box on the motor to wire it up. I wired it up on the ground and will simply lift the motor into position when the time comes to put it in the column. Below are some photo's of wiring the motor up. When I removed the cover on the junction box, the motor terminal links were pre-set to STAR. I removed the terminal nuts and mooved the links to DELTA. My VFD put's out 3Phase 240V, which will run my motor in DELTA. I also removed the junction box and rotated it 180Deg so that the gland faces the cable in an easy direction for when the motor is mounted. I crimped some lugs onto the cable and connected them to the motor terminals.

I currently have a friends Back hoe (different one from last time) sitting in the yard beside the shed. Tomorrow I will lift up my mill and stand it back up to put onto the base. Fingers crossed all my work will pay off?????

Chich

chich2
11-25-2007, 08:41 AM
Today was a good day. I double checked everything was ready to go. Cleaned the mating surfaces with electrical contact cleaner and got all the right tools ready for the bolts. I removed the bucket from the backhoe and reversed it into the shed. I connected the slings to the lifting point on the hoe and stood the mill upright. While the mill was hanging in the air I mixed up some 2 pack epoxy filler and gave the base a VERY thin coat. I then lowered the mill onto the base and bolted it down TIGHT!!!! Each bolt got a small amount of anti-sieze on the threads.
It was reasuring to see the epoxy filler get squashed out of the join as the bolts came up tight. I used such a small amount, and it got squashed out so that to me is a good indicator that the 2 faces are both in lots of contact. The excess made a very small bead around the outside of the join which I left alone.
You will see a photo of how the 4 new internal bolts ended up. The photo is taken from where the motor is supposed to be, which is inside the column looking down towards the base.

:wee::banana: MY MILL IS BACK TOGETHER!!!!!!:banana::wee:

Chich

chich2
11-26-2007, 07:02 PM
Now that the mill is back together and the epoxy is setting, I decided to fit the new horizontal spindle motor and fit the pulley. I removed the pulley from the standard motor and boared it out in the lathe to suit the new shaft. I also machined the boss of the pulley shorter so that the pulley would slide up the shaft closer to the motor, and allow the belt grooves to line up. I lifted the new motor into position and bolted it in. Next to come was to fit the pulley and key and add the v-belts.

Chich

chich2
11-26-2007, 07:25 PM
The Verticle spindle motor got the same thing done to it as the previous post.

Here's some pix.

Chich

digits
11-27-2007, 06:10 AM
Nice work Chich :)

That should be a lot more fun with 3HP on each spindle - I'm just glad I don't need a JCB to assemble my mill though :eek:

chich2
11-27-2007, 09:08 AM
Thanks Digits.
Yep 2.2Kw or 3Hp should be enough to put some decent "Whoops" marks in my table.

I am used to working in a workshop with an over head gantry crane. This buisness of using floor mounted cranes and backhoe's is a pain.

Thanks for your post,
Chich

philbert
11-27-2007, 07:48 PM
Hey Chich,

Are you planning to do anything to the vertical gearbox? That thing is a nightmare to change speeds; I'd love any suggestions you might have (short of replacing it; my ultimate plan! ;))

chich2
11-28-2007, 08:27 AM
Phill,
I am adding a Variable Frequency Drive (VFD) to the mill. The VFD will take commands from the PC and Mach3 to vary the spindle speeds. The g-code will tell Mach3 what speed to run the spindle at and the spindle will go that speed. I don't think my motors will produce much torque down at low speeds so I will still need to make speed adjustments via the belts but no where near as often as before.
The VFD will realy come into play once I make my "Swiss style" or "Gang lathe" attachment. I will attach tools to the table and put a chuck on my horizontal spindle and use it as a small cnc lathe. Since the spindle is variable speed, Mach turn will run the tooling at constant velocity. This means that the cutting speed past the tool stays constant. The spindle will slow down when turning large diameters and speed up as the diameter get's smaller. Cool stuff hey.

Chich

chich2
12-15-2007, 06:48 AM
Hello again.
Now that both single phase motors have been removed from my mill and the horizontal spindle has a 3 phase motor mounted, I needed to do some milling on the next 3 phase motor for the verticle spindle. The horizontal spindle motor is a simple foot mount so fitting it to the mill was easy. (as can be seen in previous post's)
I wired up my new VFD to the horizontal spindle motor and gave the motor a go.
Here is a video of it:
http://www.youtube.com/watch?v=2A8TLMZLuas

Chich

philbert
12-15-2007, 03:38 PM
Thanks for the update chich. What is the speed range of the spindle now?

epineh
12-15-2007, 09:21 PM
Hey Chich, I am just doing your control box drawings up today, and have a few questions, I was going to PM you but others may get some info out of this as well :)

Firstly, the spindle speed control from Mach is a PWM signal but 0-5Volt, your VF drive needs 0-10Volt analog input for speed control, I thought you could cheat and set your frequency to double of what you would use then the 0-5Volt would give you a max of 50% speed...or really 100% of what you need... but that is a little, erm agricultural :D

I started designing a board but thought surely someone has done this before, a quick google found this :

http://www.cncathome.com/vfd.html

Not a bad little walkthrough, I also like the idea of optoisolating your PC from the VFD. I think it could be even simpler by getting rid of the chip and using a simple resistor/capacitor to change the PWM to analog. I have some opto's coming in the mail so I should have that covered.

Now for the question... where would you like the board to go ? If you have room in your electronics enclosure it would be nice to put it there and not clog up my nice control panel :p

Also I guess you will want to opto the coolant output... anything else ?

Cheers.

Russell.

chich2
12-16-2007, 05:30 AM
Phil,
I have the VFD set to a max of 60Hz. I get almost 3000rpm on the verticle spindle but I cant remember the horizontal speed. I think I clocked it in at 1900rpm or sommething like that. I get the same spindle speeds as before when I run the motors at 50Hz as I have not changed any pulley sizes. I measured the RPM with a strobe light that has a digital readout.
I'm interested in doing some heavy milling to see how much torque I now have with the 2.2Kw motors.

Chich.

chich2
12-16-2007, 05:54 AM
Russ,
I can't find where I put the info I had on the PC to VFD hook up. The data sheet for my CNCTeknix breakout board says "PWM outputs 0-5VDC for spindle control" I talked to Delta (VFD Rep here in Austalia) and also CNCTeknix and they told me to put a capacitor and a resistor on the input line and it should be ok. Problem is, it was a long time ago and I cant remember the values of the components. I can call them again and ask if you like.

I realy like the opto isolated board you mentioned. Could save me a lot of bucks if I get something wrong. I have plenty of room in my servo drive enclosure to fit the board if is small and easy enough for you to make. Sounds like the go to me. The opto isolated coolant output sounds like a good idea too. I will e-mail you the layout of my breakout board and relay board for you to have a look at.

Chich

chich2
12-16-2007, 06:09 AM
Hopefully my previous post has an embeded video clip in it of my horizontal spindle spinning?

Once I finished playing with the new variable speed spindle it was time to mill some curved slots in the flange of the new verticle spindle motor. I clamped the motor down to the table. I used a 18mm insert slot cutter in the horizontal spindle and used a Mach wizard to generate the g-code to make the curved slot and 2 holes. I also made a new Mach profile which is X,Y and Z axis's in relation to the Horizontal spindle. All this basicaly means is the the profile swaped the Z and Y axis.

Once everything was set up I ran the program and milled the new motor.
The slot and holes are for drive belt adjustment just like the standard hafco motor had. I also made a black poly spacer to fit the motor spigot.

Chich

epineh
12-16-2007, 08:16 AM
'Tis done, attached are pics of the spindle speed schematic and board layout, connections are marked as required, not much more to say :D

The +5,+12 and Power Gnd on the bottom of the board is for the logic supplies to give LED indication on the electronics enclosure of logic supply available, the pinheader makes it easy to hookup, just use the little black plugs found on old PC's for the HDD LED's, Pwr switch etc and you are in business :)

Russell.

RotarySMP
12-16-2007, 10:44 AM
Thanks for posting this Russell. Could you please also post a bill of material?

davo727
12-16-2007, 06:47 PM
Looks good chich, Im still watchin. Im accumulating parts for my RF45 clone and hope to make some visual progress soon. Dave

epineh
12-16-2007, 09:26 PM
Thanks for posting this Russell. Could you please also post a bill of material?

No prob Mark, the components will be about the $3.00-$5.00 mark, and you could use one of those small prototyping boards that sell for a couple of dollars. I will be printing my own PCB but the circuit is simple enough to do on a prototype board.

Funnily enough the connectors are about the most expensive part at 66cents for the 3way and 53cents for the 2way. The IC's come in at a whopping 33cents for the 4011 and 20cents for the PC817... lol. The Opto I used is just what is easier for me to get. Prices are in Australian dollars by the way.

Russell.

chich2
12-17-2007, 05:45 AM
Good one Russ!.......................................... AGAIN!
The board looks great!!!
I can solder it up if you can drill the holes in the board for me.

Absolutely awesome!!!!

Chich

epineh
12-17-2007, 06:27 AM
Hey Chich, I should be able to print the board this weekend, if not earlier. I am still waiting for a parcel of electronic stuff and of course the opto's are in that lot (chair)
The good news is that I happen to have a 4011 amongst my pile of stuff, so I don't have to order one in (and take more time)...not to mention the financial windfall :D

I will have the rest of the stuff so all we will be waiting for will be the opto.

Russell.

philbert
12-20-2007, 02:13 AM
chich,

How much did the VFD and motor cost you in the end, if you don't mind me asking? I am thinking of using a VFD setup in my own HM-52 modifications.

chich2
12-22-2007, 11:39 PM
Phil,
I belive the answers to your question is in posts:
http://www.cnczone.com/forums/showpost.php?p=292229&postcount=119
And
http://www.cnczone.com/forums/showpost.php?p=296825&postcount=131

Chich

chich2
12-27-2007, 07:02 AM
Last week, Epineh here at the zone pulled another terrific stunt. What he has done is supply and wire up a very impressive enclosure for my VFD and spindle selector. It holds my VFD and braking resistor, it has a selector switch on the front pannel which uses a relay to pull in the motor contactors for each of my spindles. It also has a relay to turn my coolant pump on and off via Mach3.

The front pannel has a main power indicator, a spindle selector and selected spindle indicator, a VFD fault indicator, and a VFD fault reset button. The lable stickers are temporary for now and I have to get some lids for the cable ducting.

Very happy with how it turned out,
Thanks Russ!!!! :banana:

Chich

epineh
12-27-2007, 07:42 PM
My ... that is a very nice enclosure...and it looks strangely familiar :D

Some duct lid will make it look a million bucks (or near enough)

Now you need a way of engraving some traffolyte labels for the front panel... if only you had access to some kind of machine rigid enough and with CNC control to be able to cut out some nice looking labels... I don't know where you could possibly find something like that ... :)

Russell.

RotarySMP
12-28-2007, 12:42 PM
Hi Russell,

Sorry, I wasn't clear, by bill of material, I didn't mean what it cost, but a list of the required components. What are the values of the resisters, caps etc please.

Thanks

epineh
12-28-2007, 06:50 PM
Hi Russell,

Sorry, I wasn't clear, by bill of material, I didn't mean what it cost, but a list of the required components. What are the values of the resisters, caps etc please.

Thanks

Ah, my bad... I think I will test the board before I put the exact components on, but I will post the component list and board layout just as soon as it works, I kinda got a little distracted last weekend but will get back to the board next week, which also happens to be next year :D

Russell.

RotarySMP
12-30-2007, 03:42 AM
No hurry, I think a number of us will be a little distracted this next week. :)

chich2
01-19-2008, 07:25 AM
Today I removed the back plate in the cabinet that holds all my spindle controlls. (This was done so I don't fill anything with metal swarf from cutting holes). I then went about mounting a 240V AC cooling fan to the enclosure. Firstly I stuck masking tape to the enclosure so when I cut the hole with the jigsaw I don't scratch the paint. I got a fan grill and filter from Jaycar and marked out the kinda round funny shape on the tape. I then took my jigsaw and cut out the hole. Next was to mark the holes and tap threads into the holes in the fan. All that was left to do was screw the fan and filtered grill to the hole.

Here's how it turned out.


Chich

SimjetAU
01-20-2008, 05:51 AM
HI Chich

I have been following your progress and you have supplied a wealth of info. I want to convert my X5015 mill in a similar way to you mill. I was looking for cheap ballscrews and I gather you got yours from Action. I havent found anywhere in your posts where you give an idea of the difference between now having ball screws as opposed to the original acme threads.

chich2
01-20-2008, 06:52 PM
Thanks for the post SimjetAU,
The difference between my acme threads and my ball screws are huge. Each axis is very easy to moove and the backlash is almost non-existant. Just depends on how much you pre-load the ball nuts. The acme double nut setup I had was very dificult to stay on top of the adjustments. Here's what I didn't like about it:

If there was say 0.02mm of backlash with the doubble acme nuts - then the machine would be ok to use but with still some drag but 0.02mm backlash.
If I were to try and adjust out 0.02mm down to 0.00mm well then that's a lock nut senario and nothing mooves. There is simply no clearence in the thread any more. The problem therefore is that you have to keep adjusting the nuts all the time because when they are set to a low backlash - they wear very rapidly. Then you have to adjust them again.

The ball screws how ever. I have adjusted them twice I think. The first time I went pretty light with the preload but found the machine was very springy then. In this I mean you culd turn the hand wheel very slightly and the axis would not moove. This is not back lash in terms of clearence but more so an issue of the nut loading up before something would moove.
To remedy this I simply increased the preload on the ball nuts..... (not crazy load. enough to do the job) Beautiful thing! The ball nuts take load and do not increase in drag.

To sum up. I realy like the ball screws. They were cheap (compared to ground and preloaded nut types which are approx $700Au PER NUT!) easy to install and work very well.

Chich

SimjetAU
01-20-2008, 07:20 PM
Hi Chick

Thanks for the quick response. Yes I like the pricing on your ballscrews...just to confirm that you get the ballscrews from Action?...If it was I will ring them today and get a set for my mill and do you think it was worth it to use the double ballnuts?...its just that this may make mounting on my machine a bit more difficult. A local here in Brisbane modified his X5015 with stepper motors and I have the steppers and also the toothed gears and belts already, these are all easliy got and not that expensive from Naismith Engineering in Victoria. I think I will get rid of the steppers and go for servos after doing a lot of reading on this site. Also I note you used optical encoders for your servos but I think the best would be binary encoders and these are usually built into the servos from what I can gather. What power (oz/per inch) servos do you have I dont think anywhere in your posts you tell us. My machine is a knee machine and Justin who did the similar machine used gas struts on the knee on his machine and it seems to work well. I suppose it depends on the weight of your job. I have some pics of his machine which I will post here. It was done about 4 years ago.

Regards

Mark Kyle

www.kyle.com.au

chich2
01-21-2008, 08:00 AM
Mark,
Yes I got my ballscrews from Action Bearings in Breyside NSW. They are not like normal ball screws. They have a strange profile along the screw. Mine are not ground they are just hot rolled. From Memory they are something like acurate to 0.02mm per foot or something like that. Pretty good for me especialy because I will probably never need to be more acurate than that any way. Each nut has a bit of backlash in it so you will need 2 on each axis so you can pre load them apart to eliminate the backlash. You may get away with just 1 on the Z axis but 2 will guantee position.

I haven't had much to do with Binary encoders so I can't realy comment on the use of them.

I have no idea what the torque my servo's produce? I put them together myself and will probably soon change them all over to the same type of motor that's on my Z axis because I often get anoying trips on my current X axis drive because I think the motor on there now has a bug!

Chich

chich2
01-27-2008, 05:14 AM
The cooling fan is mounted in the bottom sucking filtered air in, and I wanted the hot air from the VFD and components in the VFD enclosure to vent out through the top. I removed the cover from the top of the enclosure and cut out a piece of preforated sheet metal to the same size and shape. I then took a new CHUX cloth and cut it the same shape to use as a air filter. I do not want dust entering the enclosure.

Here's some pix.

The first photo is just one of the cable gland holes I drilled in the bottom.

chich2
01-27-2008, 06:14 AM
This post shows how I attached my VFD enclosure to the main mill control cabinet. All I did was make a rear door for the cabinet from 1" box section pipe. Connect the door to the cabinet and then sheet it. After that I bolted the VFD enclosure to the door and reinstalled all the internals.

The last photo show's how I actually have the unit set up when I use the mill. I open the rear door fully so it swings right around and faces me. This way I can easily switch from the horizontal spindle to the vertical one simply by the flick of a switch. In the next few weeks, Epineh here at the zone will make me an interface circuit to go from my breakout board to my VFD so I can controll the spindles from Mach3. I hope to post pictures of it being made and details of the circuit when it is being made.

Chich

chich2
03-04-2008, 07:59 AM
Hello Zoners!!!!

It's been a long time since I last posted. Mainly because I haven't done much to the mill lately. Yesterday and today was different story though.

For a long time I have had a lot of difficulty tuning my X axis. The PID control on that particular axis has just about driven me nut's!!! :mad:
I have had Babind01 come over with an oscilloscope and even then we could not get X to behave.

I have 2 more bigger motors the same as I added to my Z axis so I decided to put an encoder on a motor and mount it to my X axis.
I firstly fiddled a bit more with my servo drive and then sat down for a while and wrote a g-code program to make the new mount. I used the Mach Wizzards and simply cut and pasted the bits I wanted into my program.

The program starts by drilling some 5mm holes in every position the milling cutter has to plunge.
Then I set a tool change and started milling.
Once all the holes were cut out, I used another Mach wzzard to face the entire face of the mount.
Then I clamped the mount on it's side and milled another hole for a cable gland to go into.

CNC RULES!!!!!!! :banana::banana::banana:

Here's some Pix. Same as usual.... hover your mouse pointer over the photo for a brief description.

Chich

P.S.
I am currently working on a new video to add. I will post it soon.

chich2
03-05-2008, 08:13 AM
Here is a video of my Mill making my new X axis servo motor mount. The vid starts off with a 5mm twist drill pilot drilling all the plunge holes that the end mill will take. Then a 6mm Ball end mill cut's all the slot's and holes. Then a 12mm insert cutter takes out all the smaller holes for cable glands and then faces the mating surface of the servo mount.

Enjoy,
Chich

<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/h0TMcbaVi3A"> </param> <embed src="http://www.youtube.com/v/h0TMcbaVi3A" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

Apples
03-08-2008, 08:18 PM
Chich,

How come you used a small 12mm bit for facing the whole bit of steel? Why didn't you use a larger bit, like a multi cut face mill thingy or a fly cutting attatchment?

Is it just because you don't have any?

Peter
Toowoomba

chich2
03-09-2008, 07:28 AM
Hey Apples,
Thanks for the post. Very good question you ask. It's actually funny because when I used that cutter I was wondering if someone was going to ask me that so top points to you!

The only reason I used such a small diameter cutter (12mm) was because I wanted the cool pattern you get form multiple passes. I have got a 18mm and a 63mm insert cutter as well but decided to give the 12mm a go as it was still in the machine and zero'd.

Cheers,
Chich

Apples
03-10-2008, 06:49 PM
I've been reading up about warpage and distortion with machined parts. People tell me that like what you are doing in the video will cause the box steel to warp and stress bend out of shape.

Have you noticed any of that? Surely by machining it the surface will be flatter that what it was originaly even if it does warp a bit.


Could you cut faster than that with your machine? When you cut the holes/slots out, it was very slow. Could you cut faster? Same with the surfacing, could it have cut faster?

Peter

chich2
03-12-2008, 05:35 AM
Apples,
Yes the RHS (Rolled Hollow Section) does warp. There is an amazing amount of stress in RHS and when you cut pieces out of it the stresses are relieved and therefore it warps. I found this happened to my Y axis motor mount when I made it. For example, take a quick look at what happened in this thread on page 6, post 62, photo number 3. You can see how much the side of the RHS "bowed" as it was cut out of the section.
I didn't wory about it too much because the warped amount on the flat milled side can hardly be seen with a straight edge. Very small.
The new part in the vdeo on post 224 didn't warp at all. What you say is exactly right. The machined surface on this mount is definately flatter than the original surface.

To your question on the feed rate of my cutters in the vid. It is quite easy to calculate the feed rates and spindle speeds for machining this job out. Yes my machine can go much faster but I would have destroyed the cutter. The first cutter I think your refering to is a 6mm solid carbide 2 flute ball end mill cutting the slots and holes. The cutter wasn't in the best shape when it started this job but it did the trick. If I had coolant running on my machine, I could run the spindle faster and therefore run the feed faster. But I don't use coolant because it makes a mess. So I go slower and keep it dry. The blue chips are a sure sign that this little cutter isn't going so well.

The 12mm insert cuter however is a different story. Yes I could have run flat out (3200rpm) on the spindle and adjusted the feed to suit no problem. VERY robust cutter!!
The manufacturer of this cutter and insert rates the cutting speed at 190m/min with a feed of 0.08mm per tooth. That's 5042 rpm at a feed of 403mm per minute. (15.88ipm)
I assume the manufacturers details are with the use of coolant and my spindle can't even go that fast so I just took it easy.

Hope this has helped,
Chich

chich2
04-01-2008, 09:42 AM
Finaly got to put the new motor and motor mount onto the X axis. I had to re-calculate the pulley sizes because the new bigger motor I put on spin's much slower than the old motor. I boared out the new pulleys an fitted them to the machine.

Here's some pix.

chich2
04-01-2008, 08:12 PM
Now that the new servo is mounted I thought it was time to test it on a long job. I milled a 3D face out of a piece of pine I had in the shed. The servo worked well. This is about 6000 lines of code. The 3D face came out good.


Chich

chich2
04-17-2008, 09:22 AM
Here's a short movie of the machine milling out the face.

Chich

<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/JdU90AQLH8c"> </param> <embed src="http://www.youtube.com/v/JdU90AQLH8c" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

epineh
04-17-2008, 05:18 PM
That is cool !

Also one of the biggest wood routers I have seen in a while :D

Russell.

yosefi83
04-18-2008, 03:22 PM
Nice work chich2!
Tell me please, how do you guys make the 3D CAD files? I'm planning to make some chess and I'll need to 3D mill the knights. Any idea how to do the CAD?

Thanks,
Daniel

chich2
04-22-2008, 02:36 AM
Hello Daniel,
Thanks for the post. Welcome to CNC Zone. The program that made this file was MillWizard from Delcam. Go to http://www.millwizard.com
It's actualy a good question you ask because I find it difficult myself to find CAD CAM solutions that are freely available to Hobbiest's. I tried the Alibre trial software and fell in love with it straight away. It's also HEAPS cheaper than most or ALL of it's competitors. Still too expensive for Hobby people like me. It's a shame.
There is a whole section in this forum on CAD CAM so maybe take a look there for some solid answers to your CAD CAM questions.

Thanks
Chich

yosefi83
04-23-2008, 02:17 AM
Hi Chich,
Thanks for the answer. Actually I was asking about how to produce the 3D model and not about the CAM. Do you start with a 2D picture and than convert it somehow to a 3D model?
I am a mechanical engineer and work with several CAD programs and know how to build 3D geometric shapes, but have now idea how to produce 3D artistic figures. What I know for sure is that the engineering CAD software that I use (Unigraphics, Cimatron) is not suitable for this kind of work!

Thanks again,
Daniel

chich2
04-25-2008, 08:14 AM
Daniel,
I own a Roland 3D digitiser. It is a very old machine and it's very slow but it's nice and accurate. It produces nice clean 3D scan's of organic shapes. Otherwise you will find 3d surfaces on the net here and there. The new scanners are optical and super fast. There is a thread here somewhere with people that have trialed the cheap optical 3D scanners. Maybe take a look there.
For organic shapes using CAD try ArtCAM from Delcam. They have some short video's on their website showing how to make an embossing stamp and also how to make a coin and things like that. Pretty sure they have a trial version if you want to give it a go.

Hope this has been helpfull,
Chich

yosefi83
04-25-2008, 08:54 AM
Thank Chich!
I'll look at ArtCAM.

Daniel

chich2
06-24-2008, 07:37 AM
For a long time now I have been putting up with poor repeatabitity on my Z axis positioning. In previous posts you can see where I removed the column from the base and blued and scraped them to fit. That only half fixed the problem. The next problem is caused by a silly design in the base of the machine. The area under the column is actually hollow. To make things worse, there is no webbing in the base under the front section of the column. (I have cut a hole in the top of this casting to insert my air cylinder which would weaken the base as well)
You can see in picture 2 where I have drawn a RED line to show where the casting goes. What happens is when the servo pushes the knee up, all that happens is the column flexes backwards and the knee doesn't actually moove up the column. I have drawn the flexing in YELLOW.

To correct this I was going to make an entire new base with lot's of heavy webbing. I decided not to do this as it will use a lot of steel and I'll also be left with a base that will be wasted. Instead I have decided to brace the column directly to the screw. You can see in photo 3 what my plans are. The 2 gusset strutts, one either side, will be very heavy to minimise flexing and they will be bolted tightly to the column. Everything else will be welded.

chich2
06-24-2008, 08:01 AM
So off to the drawing board I went. I cut up some steel and ground all the surface rust off. I then set up 2 of the rough cut gussets on the table of my mill and milled them to length with the horizontal spindle. Next was to face one end of a piece of 4" ASAB (hollow bar) in the lathe and sit all the pieces together to see what it looks like. The hollow bar will replace the cast tube that holds the ballnuts. This tube will be gusseted to a heavy base. The base and gussets will attach to the 2 strutts that go back and bolt to the column. The last photo is how it will look except the photo only shows one strutt in position, leaning on the bin. All of this straight steel is solid and very thick. Hopefully this works.

Tomorrow I'll tack weld everything together and fit it to the machine.

Chich

chich2
06-25-2008, 09:35 AM
Today I welded up the parts I machined yesterday. Then once it cooled down I fired up the mill in Horizontal mode. In this mode X is still X but Y and Z are swapped from the Vertical configuration. In Horizontal mode the axis are set up in relation to the spindle, as they should be. I clamped the new base to the table and faced it off with my 50mm cutter. After that I used a Mach3 wizzard to pocket a 40mm hole right in the middle of the plate. This hole is for the ball screw to poke through like the standard one does. After the machine had bored the 40mm hole I decided to take it out to 52mm for more clearence incase I need it in the future. A Mach3 wizzard was used for this again.
I realy like using the Horizontal spindle.
Firstly I run oil in the horizontal spindle and it flows to both bearings. Because of this I can run higher than normal spindle speeds on this spindle than the verticle one. With the bigger 2.2Kw motors I can drive the cutter without the risk of stalling it.
Secondly the Horizontal spindle is realy rigid!
Thirdly when you cut a deep pocket, the chips simply fall out!!!! unlike a verticlal pocket where I need air or coolant to blow the chips out.

Any way here are some pictures and a video will follow in my next post.

Chich

chich2
06-25-2008, 09:38 AM
Here is the Vid


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Chich

chich2
07-04-2008, 07:31 PM
Yesterday I cnc drilled the hold down bolt holes in the brace. I then clamped the brace onto the machined surface and faced the top off parallel. After that the knee was raised to full height and locked off. I left the air pressure on the cylinder for added safety to keep the knee from slipping down and then removed the standard Z nut support. The new one was then put into place and measured off against the column. I then drilled and tapped 2 holes and bolted the brace down. All the other holes were then drilled and tapped using the bolt patern in the new brace as a template.

Today I'll machine the brace strut's and fit them to the machine.

Chich

chich2
07-05-2008, 09:40 AM
Today I CNC milled the hole in the hollow bar bigger to give the ball nut a bit more clearence. I could only go down 24mm until the depth of cut came close to the shoulder on the shank of my insert cutter. After that I dug out me old boring head and took the hole down to depth. (45mm)
Next thing to be machined was the angle on the bottom of the strutts. I clamped both down together on the table and cleaned up the face with the horizontal spindle. After that I drilled the bolt holes in the strutt's.
I drilled 1 hole in the column and sat 1 brace into position.

That's it for now,
Chich

chich2
07-06-2008, 08:30 AM
Next was to draw around the strutt with a pencil and mask around it. I then chiped away all the filler / grout where the strutt will bolt on to the column. This was done on both sides of the column for maximum grip of the strutt to the column. Once scraped and a heavy go over with a wire brush I gave the surfaces a de-grease and a light coat of Zinc undercoat to prevent rust.
I then de-greased all of the other parts of the brace and hosed them off with clean water. An LPG torch was used to heat all the parts up warm to touch to drive off any moisture. This was followed by painting all the brace parts with the same Zinc undercoat and then bolting it all to the machine once the paint had dried. I drilled and tapped all the holes into the column M10X1.5 and did the bolt's up tight.

Now that the Z nut brace is square to the screw and the strutt's are in position, all that needs doing is to weld the strutt's to the base.

Chich

chich2
07-08-2008, 09:40 PM
I welded the Z nut support and strut's together yesterday and masked it all up ready for painting. First was a coat of super etch as an undercoat. This went over the zinc as it turns out the zinc is not compatible with the 2 pack top coat I wanted to use. The super etch was allowed to dry for a day. I got some paint colour matched to the machine in a 2 pack paint. I mixed some up and painted all the brace steelwork.
Today the paint is dry so I removed all the masking tape and paper. I could not wait to see the final outcome with a dial indicator on it and see how it went. So far it seems there is NO flexing occuring whatsoever but I find that a little hard to believe. I will be doing some test this afternoon to see for sure.

Here's some pix,

Chich

cjmerlincnc
07-26-2008, 01:28 PM
Hi Chick2, I've been reading your post since a year ago I happened to
purchase a similar mill to yours, a ZX7550 what ever that is.

It just has the vertical spindle and the usual Chinese finishing touches.
The only obvious differences I've noticed is the Z leadscrew nut housing is tapered on mine and is 5 1/2" in diameter on the base, there is a rising in the floor casting of about 1/4 inch high for it to sit on, so mounting an air ram is going to be tight.

Having a poke about in the suds sump in planning to cut the hole for the air ram I noticed that the area under the column on mine is solid all the way to the floor with a 4" x 5" hole through to the center of the column.

I'm now at the stage where I need to do the knee mods for the ram and I'm a bit reluctant to go at it with the angle grinder although I know it has to be done to get the ram in.

I also have the added problem of not being able to get the knee off the column to work on it as I do not have any lifting gear or strong beam to throw a rope over to carry the head off the column.

I think with patience, cunning, skill, whatever, I should be able to get the grinder in there and remove that casting rib.

Just a question, have you had any adverse problems due to cutting that vertical rib from the back of the knee?

Also, I'm planning to get oil to all axis, the z axis has no oiling points on mine and due to not being able to remove the knee is going to cause me a headache but I do have ideas so fingers crossed.


Keep up with the good work it has been an informative and enjoyable pleasure reading your project posting.


Cheers
John

breck
07-27-2008, 02:56 AM
Hey Chich, looks awsome! I got on this great forum because I am building a cnc router and find you 5 minutes down the road. Andrew said you had retro-fitted a mill but didnt realize you were on here. When are you home next? I will give you a call,I have been meaning to for ages. I'd love to have a closer look. Breck

epineh
07-27-2008, 05:13 AM
Hey Chich, looks awsome! I got on this great forum because I am building a cnc router and find you 5 minutes down the road. Andrew said you had retro-fitted a mill but didnt realize you were on here. When are you home next? I will give you a call,I have been meaning to for ages. I'd love to have a closer look. Breck

Hey Breck, well either you are 10 minutes from me or you live practically next door (I live about 5 mins from Chich), I think we should catch up as well, good to hear of another local getting addicted to this stuff :)

Cheers.

Russell.

breck
07-27-2008, 07:15 AM
Hey Breck, well either you are 10 minutes from me or you live practically next door (I live about 5 mins from Chich), I think we should catch up as well, good to hear of another local getting addicted to this stuff :)

Cheers.

Russell.

Hi Russell, I am the other way I think (Bellenden Ker). And if I am right, I think Andrew has spoken about you as well. He was going to give me your number I think, so I could come and see your router but we never got around to it. He is the reason that I "got addicted" so to speak. I can do the fabrication side of the router no worries but I am going to need his help with electronic side as I have no clue. I got a good few days on the school holidays so got in and have the frame 80% done, X and Y are sliding nicely still thinking about how I want to attack Z. I'm really getting into it and am lovin it! Isn't it funny whats just down the road, and Chich as well. We should catch up soon. Breck

epineh
07-27-2008, 08:20 AM
Hi Breck, I think we could probably help out a little with the electronics, I will PM you my details. Are you going steppers or servo's ? (I could help more with servo's :D)

Cheers.

Russell.

chich2
07-27-2008, 08:28 AM
John,
(cjmerlincnc) Thanks for the post and the question. To try and sum up your question as quickly as possible I guess my reply to you will be:
1. Because your machine does not have a Horizontal spindle I would not bother automating the Knee. I only did it because I also have a verticle spindle and wanted CNC use of both spindles AND I have huge runout on my Quill from factory. If your Quill is a good fit when it is extended all the way out and has no radial movement then I recomend you CNC your quill. In this case, when milling a job you would set up your knee in roughly the correct possition and lock it off so the quill does the actual CNC movements.

2. From your description, your base is made a lot better than mine so I'd be hesitant cutting holes in it. If I was to do this again to a HM-52 think I would make a drive mechanism that connects directly to the sides of the column and drives the knee off the column rather than the base. Then flexing and leverage would therfore be eliminated. I think it would be made to fit snug against the column and knee so it is rigid and VERY direct acting in it's movement. The weight of the knee would be offset by counterweights on roller chains up and over the column, with the weights hanging behind the column just like the head does on an industrial CNC machine.

3. I have not seen any adverse effects from removing the vertical rib from the back of the knee.

Hope this has helped you. Feel free to ask more questions if you ned to.

Chich

chich2
07-27-2008, 08:41 AM
Hey Brek,
Small world huh? Been a while since we crossed path's. And now were Yarn'in on an international forum. BIZZARE!!!!! Yea home made CNC gear is pretty addictive!!!!! I see you have chatted to Russel in the thread as well........:D Great bloke to know when it comes to affordable CNC drives. :stickpoke Russ has successfully designed and built his own srevo drives which do a great job driving his CNC router. Nice rigid machine too.

I sholud be home again this weekend if all goes well. Andrew will tell you where to find me.

Chich

cjmerlincnc
07-27-2008, 05:26 PM
Thanks Chick2 for your quick response. You put forward some very good points. I like the idea of driving the knee from the column. I'm pretty set with the ram idea because it's easy and simple to do and later I plan an auto toolchanger and need all the space on side of the mill for it plus the quill wouldnt be up to continuous daily milling for too long before it got sloppy. The counterbalance knee idea is probably the best method but involves a hell of alot more work and design if I want to keep the swiveling head arrangement. I'm planning putting a high speed (10k rpm) head on the other end of the ram for small 3D work.

I'm currently sorting the knee oiling situation.


If I get anymore questions I hope you don't mind if I send you a PM as I dont
want to mess up your excellent build log/posting.


Cheers
John

chich2
07-27-2008, 06:53 PM
John,
I would like to see a thread with your tool changer when you build it. I think the CNCZoner's here would also like to see a thread of your machine conversion. Great idea for the high speed spindle on the ram.
Yes please PM me with questions if you have them or post them in the thread if you feel someone else may also be interested in your question.

Chich

chich2
08-05-2008, 08:23 AM
Hello ZONERS!!!!

Here is my latest work with the converted HM-52. The brace job on the column has worked a treat and I have been doing some cool stuff with the machine. Here is my latest job. It is a cooling water jacket off an old Mercury outboard motor my dad is restoring. He said the part is no longer available from the manufactuer any more so I said I'd make him one.

First thing to do was measure it up. I did this with a height gauge, and used my table as a surface plate. I measured every single thing I could along the part's X and Y lengths. This made it real easy to draw later. I downloaded the trial version of CADEM's milling program CAPSMILL. The software is easy to use but from my experience it has lots of bugs!!! Could just be my PC too as I havent tested it on another PC. ANYWAY, CAPSMILL generated the toolpath and away I went.

Chich

chich2
08-05-2008, 08:31 AM
Here are some Vid's of the job.

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<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/aJI7I3yUBh0"> </param> <embed src="http://www.youtube.com/v/aJI7I3yUBh0" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>



Chich.

cjmerlincnc
08-05-2008, 09:58 AM
Hi Chich2, Nice work mate. Yes I do intend to do a project log of my mill. I've got lots of photos as I've progressed and as soon as I've completed the axis's I'll start putting a log together.

Keep up the good work.

Cheers
John

epineh
08-10-2008, 06:20 AM
Awesome job on the water jacket Chich ! You will have to make another one to sit on the mantlepiece :D

Russell.

evo4wrx
09-10-2008, 11:20 AM
Hey been slowly getting everything together and taking some of your advice from a previous email...would I be better off to convert the quil rather than the knee to get my Z axis?? Its the same Hafco as your except the 3 phase version. I see what you mean by the base flex....

FPV_GTp
09-10-2008, 11:52 PM
wooooooooooooooo CADSmill is not cheap CAPSmill 1350 +VAT


Nice work chich2

cheers

chich2
09-11-2008, 08:01 AM
evo4wrx,
Good question you ask..... If you are never going to use your horizontal spindle for cnc (which I do use mine for a lot!!!) then DEFINATELY Z the quill. You will have to do some work on the quill run out as it is very poor on these machines. The use of a product like MOGLICE http://www.moglice.com/ will save you a lot of trouble and it's something that you can re-do if it wears out. Have a quick look at how they fixed a quill on a horizontal boring machine http://www.moglice.com/newsite/appexamppages/rebuildingmach/ingerappexamp/ingerframes/ing1frame.html Only Z the knee if you are going to use the horizontal spindle like me. Looking forward to see a thread on your build when you start.


HPV GTp,
I was using the trial version of CAPSMILL but it has expired now. I won't be purchasing it because, like all CAD CAM programs they are just too expensive for home hobby people like us. Be great if there was a good bundled program out there free for non proffit people like us. That so far has been the most challangenig part of home CNC I have found. It is a real problem. I am begining to understand the position software hackers play in the under world!!!!!!! Not that I support them in any way.

Chich.

chich2
09-21-2008, 10:13 PM
Well Zoner's I've been in the shed over ther week end and I started making my horizontal spindle lathe conversion. The plan is to have a thick plate that bolt's down to the table which holds a gang of turning tools. When I need to cnc a small turning job I'll simply bolt the tool gang down and zero the first tool on my touch probe. The tool table will have offset's for each tool so I should be able to call on which ever tool is in the gang.

Please note that the tool gang plate will take me some time to make so I'll just show where I'm up to.

I was going to simply use a collet chuck to hold the material that was to be cut for each job but the problem is I would be limited to the maximum collet size in my ER32 range which is 20mm. That's big enough but the next problem with using a collet chuck is that once the job is finnished, there is that little bit of stock left in the chuck. Since the drawbar holds the collet chuck in the spindle, then the longest piece of bar I can hold is what ever fit's up inside the collet chuck. If I was doing say 100 item's of something then I would be left over with 100 little bit's of bar that I can't realy use and therefore be waste!

SO I decided to attach a small 3 Jaw chuck to the horizontal spindle using a backing plate. The backing plate has a 30mm hole in it the same diameter as the 3 jaw chuck and the large end of the spindle taper. The spindle has a through hole 17.5mm which normally fit's the drawbar. Using the 3 Jaw and backing plate means I can now hold a much longer piece of stock than what I could with a collet chuck, therefore less waste.

I started by cutting a piece of 150mm X 32mm (6" X 1 1/4") high tensile flat bar from the rack and put it in the mill to make it round.

This stuff is tough. It's called something like RESIFLEX or RESOLFLEX. (It is used to make ripper tynes for earthmoving equipment). Finish came up nice and had to keep spindle speed low.

Here's some pix. Hover you pionter over the thumbnail for a description.

Chich

chich2
09-22-2008, 12:11 AM
Next I placed the blank into the lathe and machined it to fit the mill spindle. Because the hole centres for the mill spindle are bigger than the hole in the chuck, the chuck covers them up when it's bolted to the plate. So I had to make the plate with enough space bedhind it to get the bolts through the plate into the chuck. The spigot on the back of the plate was machined to be a neat fit onto the spindle. I removed the drive dogs from the spindle and pushed the plate onto the mill.
Chich

chich2
09-22-2008, 12:30 AM
It was then time to bolt the plate to the spindle.
I made a g-code from the Mach3 wizzards to counterbore and drill the 4 holes that secure the plate to the spindle.
I should make a mention that there is a realy cool wizzard in Mach3 that find's the center of a circle if you indeify 3 points allong the circle. VERY Usefull. I use my touch probe to simply touch anywhere on the circle. Selct it as point A. Then touch anywhere else allong the circle. Select point B. Do the same for point C and then click the "Go to circle center" button and the the machine drives to the center of the circle. AWESOME!!!! No more finger dial for me!!!
ANYWAY,
After the counter bore I drilled 11mm holes through to accomidate for the mounting bolt's and put a small chamfer on the holes with a counter sinking bit. Following this was a quick clean and then I bolted the plate to the spindle with four M10 socket head cap screw's

Chich

chich2
09-22-2008, 07:06 AM
I had to do the next bit a bit weird because I only have right hand turning tools and havent got my variable speed spindle set up to go in reverse.
I clamped a right hand turning tool to the table and used a Mach3 turn wizzard to face and recess the plate. You can see the finished product in the last photo. I realy enjoyed seeing the machine turning by itself.
I am currently putting together a video of this face plate job that I will post in the near future.

Chich

chich2
09-22-2008, 07:07 PM
The pictures realy tell the story here.
Once the machine had finished machining the face plate, I jogged the table and tool out of the way and placed the new 125mm 3 Jaw into position. All that is left to do is drill the mounting holes and bolt it on.

Chich

SpeedsCustom
09-22-2008, 10:04 PM
Thats really awesome :) Nice job!


-Jason

Mallala_John
09-23-2008, 02:07 AM
Saw your post and thought I would say my bit. I too am a nooby in the milling & turning game and I have been following chich2 with great interest. I am continually amazed at his skill and ingenuity. With such inspiration I have enrolled in a TAFE course earlier this year and am having the time of my life. It is great thoroughly recommend it.

John

chich2
09-23-2008, 03:03 AM
Jason,
Thanks Mate!

John,
Thanks for the kind words. GREAT to hear you are going to TAFE and enjoying it. It's a very constructive trade / Hobby to be involved in. There's no end to the possibilities to what you can do. I see it's your first post here at the ZONE!!!!! Congrats and welcome!!!!!!!

Chich

chich2
09-23-2008, 03:14 AM
The last part of mounting the chuck simply involved CNC drilling 3 mating holes in the plate to suit the chuck and then bolt the chuck on.

You can see the through hole in the spindle in one of the pix.



Chich

P.S. Video Is on it's way!

chich2
09-23-2008, 08:21 AM
Here is a video of most of how the plate was made and the test running of the spindle with the chuck on it.

Hope you all enjoy.

Chich


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chich2
11-01-2008, 08:17 AM
Up until now I have been powering my mill servo motors with big lead acid batteries. It has worked very well up until now. I have been trying to tune my servo's to their optimum but I could never really get it right. The main reason was that I simply wasn't giving them enough volts. The servo's couldn't react quick enough to be able to tune them properly. Epineh and Babinda01 told me to increase the voltage so that's what I did. I simply added 12Volt batteries until I got the motors to react the way they should. In the end I had five twelve Volt lead acid batteries hooked up producing about 63volt's. The servo's then became a different beast then!!!!! Very solid and very responsive. Scary thing was that I was sitting on about 400 amp/hours!!!!!!! Very scary! Epineh gave me a BIG resistor and a momentry switch whick I connected to protect against this huge current inrush on power up.

Now that I know I need at least 60Volts and my servo drives are good for 80volt's it was time to design and build a mains power supply. Babinda01 and Epineh spec'd up all the components and I purchased them all for Jaycar in Cairns. The other day before coming back to work, I put it all together and tried it out.

Here's some pictures.


Chich

Mallala_John
11-01-2008, 09:36 PM
That looks a very good job chris. Hope it works OK.

I have my HM52 up and running now and trying to get to grips with it.
The machine is great but the operator...............ugh!

John

chich2
11-02-2008, 05:25 AM
Thank's John.
I believe if I was to convert another one of these mills I think I would purchase 2 linear rails and attach the knee to the column using the rails. I would then attach the knee ball screw to the column not the base and counter balance the knee with roller chain and either a counter weight or pneumatic ram. The roller chain would track up the coulmn to a sprocket or roller then back towards the back of the machine. Here is a picture of how I would definately do it if I did do it again.

The red thing on the knee is a solid brace that connects to the knee. There are 2 red rollers on the column that the yellow chain goes over. There is a red counterweight (that way you don't need to run a compressor as well). The green ballscrew goes between the red knee brace and is positioned very close to the column. There are 2 purple linear guides between the knee and the column.

This I believe would make the most accurate setup.

Chich

epineh
11-02-2008, 06:08 AM
Nice work on getting all that into the enclosure Chich :)

It will be interesting to see how the higher voltage goes to improve tuning, should get that beast ready for some production runs :D

Cheers.

Russell.

Mallala_John
11-02-2008, 09:43 PM
Yet another clever solution Chris. I think it will be a long time before I attempt anythink like that. I feel I need to learn more on the basics of milling before I introduce complications.

Regards John

John Gargano
11-28-2008, 11:26 PM
I have read this entire thread and I am just in awe of the creativity, technical know-how, ingenuity, work ethic, engineering ability and documentation skills that have been exhibited. How uplifting! It was also great to see the spirit of cooperation and interest exhibited by others who made significant contributions to the effort.

I feel like I should print out this entire thread, make a book out of it and take it with me where ever I go. Then, whenever I become concerned about the absurd condition our planet is in - as it relentlessly portrayed by the media on TV - I will take out this thread to reinforce my strongly held belief that there is an entirely parallel universe of people (like you guys and others who have made similar contributions to the CNC Zone) that have exhibited the discipline to learn about difficult and complex undertakings and engage in all types of efforts to solve problems and relentlessly strive towards improvement of themselves and their surrounding conditions. Its not just about machines and electronics what has been exhibited here is pertinent to everything the world should be about.

The work shown here is exemplary of the finest and highest achievements of which good and decent people are capable. Keep it going and thanks for making the world a much better place!

JG

oceanvision
12-07-2008, 03:42 AM
Read through your project, quite involved, what was the total hours and cost to convert to cnc. I have just put down a deposit on a HM-52G total price AU$4800 , before a price rise of about just under $1000. i decided because it has geared head lower low speed ( for 316 stainless machining )speed and 3 phase, the only down side is slower top end speed,i would of liked a larger machine but but my work scope does not justify cost and i still have to buy tooling. Whats your opion of the HM-52 versus the HM-52G, my other gear is a hafco CL68 lathe. Quite impressive bit of engineering there by the way.
Miles

chich2
12-15-2008, 04:06 AM
Hello again. Sorry for not replying sooner. Thanks for the kind words John.

Oceanvision, I see that is your first post. Welcome to the zone!!!! Congrat's on purchasing a machine. I think the HM-52G is the way to go if you need to change spindle speeds often and you don't have a Variable Frequency Drive. The geared head would be great for that. Standard motor on the HM-52G is 1.5Kw from memory.

I havent spent more than $10,000AU on the mill. That includes the purchase price of the machine. The time I've spent on the conversion is huge!!!!

Chich

chich2
12-15-2008, 06:29 AM
Well my new power supply work's great. It produces a no load voltage at 76Volts DC and about 73 Volts DC under load. It has a maximum load of approx 12Amps.
Now that I have a higher voltage I was able to PID tune my X and Z axis servo's which have the bigger brown motors. This led to over heating of the Y axis which has the smaller Black motor. SO I prepaired another brown motor to replace the black one. I machined up 2 small stub shaft's to be a light tap fit and grub screwed and loctite'd the stub's into the hollow motor shaft. Then I set up the rotor in the lathe and machined the stub's true and to size.


Chich

chich2
12-15-2008, 06:44 AM
Once the motor was put back together and the encoder was mounted it was time to design a new mount for the servo motor and mill it out.


Chich

chich2
12-17-2008, 06:35 AM
Here are some photo's of the General layout of my mill and PC. You can see the smaller black motor on the Y axis. The next photo's show the Y axis mount with the servo bolted to it. The last photo's are of the Servo mount on the Mill.


Chich

chich2
12-22-2008, 07:48 AM
Don't worry...... It's only a cheap wood router I got from Bunnings. I plan on using it for wood jobs and also VERY light engraving work. I think I paid about $25 dollars AU for. It has a switch that latches on and a variable speed dial to go from 11,000 to 32,000 rpm. From memory I think it's about 750Watt. First thing I thought when I saw it was STICK IT TO MY MILL!!!!! :idea:
So I went about making a bracket to fit the router. A piece of 100mm X 100mm angle iron was used as the mount. Using the horizontal spindle, I CNC milled a hole in it to fit the original router base clamp. Then I faced the angle iron nice and square. I turned up 2 locating bosses in the lathe. These bosses fit neatly inside the horizontal arbour support bearing. One is parallel and the other one has a shoulder on it to clamp up tight on the support. With these arbours I can tilt the router side to side if needed. I also used a button die to run a thread down a 12.9 grade 10mm cap screw.

The last photo show's all the components.

Chich.

chich2
12-22-2008, 08:05 AM
Once all the components were made it was time to fit it to the mill. First photo show's how it all goes together. On the right of that photo you can see the hole in the horizontal arbour support that the bosses go into.

With the router set up like this I can position the dovetail ram in and out and at any angle I need and also slide the Arbour support along the ram. X,Y and Z axis setup are the ones used for normal verticle milling.


Chich

epineh
12-22-2008, 05:28 PM
That is cool Chich, looking at the last photo, do you think it will all be rigid enough to cut timber ? :D

Russell.

chich2
12-23-2008, 06:13 AM
Good question Russ. I was itching to make a small sign for my niece for Christmas so I took a piece of wood and clamped it in the vice. I milled out the text and then gave it a light sanding by hand. Next was to paint the milled out text and allow the paint to dry. After the paint dried I sanded it back to just leave the paint in the grooves.

Chich

epineh
12-23-2008, 06:24 AM
Hey Chich, looks like the mill held together under the pressure :D

Nice effect with the paint, I like how it got into the grain..very nice !!!

Cheers.

Russell.

chich2
01-25-2009, 06:42 AM
Yea Russ the paint in the wood was an un-expected effect.

Here is a quick video of the mill running with the router on it.

Chich

YouTube - Hafco HM-52 Routing wood

chich2
01-28-2009, 06:29 AM
A while back I made a backing plate to fit a 125mm 3 Jaw chuck to the horizontal spindle of the mill. Last week I needed to make a few parts so I put the 3 Jaw back on the mill and clamped a tool down to the table.

Here is a Video of my mill in action, CNC turning.

Chich

YouTube - Hafco HM-52 Converted to CNC lathe

LeeWay
01-28-2009, 09:00 AM
Very versatile machine. If I was looking for a used machine, I would narrow my search to get one like this. There ain't much it won't do. ;)
Congrats.

chich2
04-17-2009, 07:05 AM
Thanks Lee.

It's been a long time since my last post. I have been doing many jobs with the mill. Here is a job I did a while back for my mate Murph. He has a spear gun for catching ocean reef fish. The top of the gun has a groove in it that the spear sit's in. Murph purchased a moulded plastic guide for the spear to go through and this plastic giude is supposed to go over a cylindrical stub on the end of the gun. The gun was too round to go through my lathe spindle so we decided to mill it with the horizontal spindle of my mill.

Here's some Pix.

Chich

Zhyyra
06-29-2009, 03:04 PM
I'm very impressed. You did a great job converting the machine. Nice and versatilel. hope it gives you many years of pleasure.

chich2
07-01-2009, 07:55 AM
Thanks Zhyyra.
Here is a quick video of the mill doing the job in the photo's above.

YouTube - Hafco HM-52 Milling Spear Gun

Hope you all enjoy,
Chich

amacf1
10-19-2009, 08:06 AM
Hi Chick2
Like everyone else I am very impressed with your post. I too have purchased the HM52 with the view of converting it to CNC. I have a fair bit more researching but hope to make a start in the next three months - I already have made up my mind to go for ball screws - there is a manufacturer in Sydney so will take the time to visit them. In a nut shell what was the bigest point in your project you would do differently if you were to do it again?

Thanks again for sharing your project - well done.
amacf1

chich2
10-19-2009, 08:43 AM
amacf1,
Thanks for the post and thanks for the kind words. "In a nut shell" If I would do it again i'd do the knee differently. I have detailed this in post 279. Set up in this way I believe you would get a VERY accurate Z axis. I forgot to say that you'd need a servo with a brake too if you did set it up that way.

Have a quick read of post 279 and if you have any further questions dont be afraid to ask.

Chich

amacf1
10-20-2009, 10:09 AM
Hi Chich2
Thanks for the reply. I have read your posts again and am inspired. I have printed them all out and put them in a folder. I will also have another look at the knee issue. Also would you retain the handles if you had your time over?
I was also impressed with the engraving (Router) attachment and how you fixed it to the overarm support. I will follow your progress. Hopefully I will start soon.
Best regards

chich2
10-27-2009, 08:47 AM
amacf1,
Yes I would definately keep the handles. Some times I simply need to drill a hole in something so I dont even use any of the CNC part of the machine. I just start the spindle and drill the hole by hand like you would on a drill press. 1 off CNC jobs usually take me MUCH longer than what it takes to mill the job manually. I made sure my mill conversion was to keep my mill manual and CNC.

Be sure to take plenty of photo's and start a thread when you start your conversion.

Chich

amacf1
10-27-2009, 09:55 AM
Thanks again
I have a meeting with CNC Technix this Friday. I remember a quote you made in one of your posts and that was - be prepared to spend some money. I agree with that sentiment. Without just splashing money around I am prepared to fork out a bit of money. I am looking at the MultiTEK Controller PRICE $2695.00 + GST + Freight (Excludes Motors and Mach3 software). I know this is getting up there but in the big picture of things I think I will go that way. My next job is to calculate the mass, force and torque require to move the table and knee so as to obtain the correct size servo motors. I have heaps on the go at the moment but I will start a thread when I do - hopefully next week - like most people "work" gets in the way. Once again thanks for the info - You have set a high benchmark to follow but you sure have ironed out some issues I might have/will encounter.
Kind Regards
amacf1 (fellow F&M Tradie)

amacf1
10-29-2009, 05:10 AM
Another question (forgive me) - In preparation for a meeting with CNC Technix tomorrow - what size servo motors would you go for if you were to undertake the project again. Basically it will be the same conversion as yours Chich - I will need three for the HM 52 - I am going for your idea of the knee counter balance - I still have to calculate the torque required but thought you or some other readers will have an answer based on experience.
Regards
amacf1

chich2
10-30-2009, 07:56 AM
amacf1,
WOW that is a MUCH higher price than I paid for my servo drives!!!! It has been a while since I purchased my drives but from memory each Tek10 drive cost about $250 each. $120 for the breakout board , realy board $65, and opto board $50. About $1300 all up as I purchased 4 drives.

In your post you mention "CNC Technix" Do you mean "CNC Teknix"?

Im realy sorry but I cant answer your question on what size servo's to run because I made them myself. The first servo's I made worked for my X and Y axis but was not strong enough for the Z axis. The second lot of servo's I made did the job easily. If you place linear guides on your column for the knee to run up and down on and counter weight the knee then you may get away with using a smaller servo.

Chich