Hafco Metal Master HM-52 CNC Conversion

[chich2]

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]

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]

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]

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]

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/showth...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]

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]

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.....

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]

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]

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 )

Russell.

[jkujawa]

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]

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

Russell.

[Adobe Machine]

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 )