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Rodm1954
03-10-2006, 05:48 AM
I have just finished the first machine and have already started on the second. I have been collecting bits for the second and third machines for quite a few months now so at least I won't be waiting on parts. I started cutting the steel base last weekend and hope to make more progress this weekend.

I will build the strengths of the last machine into this one and look at ways of improving some of the weaker areas as well. It will be a steel base with aluminum gantry and all the rails will be commercial products rather than do it yourself. The time and cost of fabricating your own linear rails is not worth it for me. I also feel that no matter how much effort you put into making your own they are likely to be of less quality than commercial rails.

Well that out of the way I thought I would kick this thread off with a photo of my first router and then one of the rails and ballscrew I have purchased for the second machine.

As happened on the first machine I do not have drawings and apart from a concept in my head this thing will evolve as I go so it should be interesting to see the end result. I don't seem to have the patience for drawing but can tinker out in the shed for hours so I figure I may as well do something I enjoy. :)

Rodm1954
04-30-2006, 08:14 AM
After my first post things stopped for various reasons but this weekend Nobott commenced in earnest. Totally changed my ideas over the last six weeks and have settled on a 400mm by 400mm by 100mm cutting envelope. The reason for the smaller machine is that it will take up less room and be easier to enclose in a soundproof vacuum cabinet.
This photo shows the steel base with the X axis ballscrew assembly fitted. The Y axis assembly is sitting on the temporary table and the linear rail will be fixed on the sides of this unit.
The sides have been extended above the table to protect the linear rails from sawdust and swarf.
The frame measure 600mm by 500mm at the moment but it will grow as the gantry is built.

Rodm1954
04-30-2006, 08:21 AM
This photo shows the frame with the temporary table removed. Perhaps it would have been easier to get a cast iron block and shape it. :)
I like a heavy base on machinery so I think I have achieved this as I can only just lift it now. Next step is to break it down, cut the bolts to size, shape the steel a bit and then prime and paint it.

Rodm1954
04-30-2006, 08:23 AM
Last photo for tonight shows the underside and ballscrew assembly. I might drop out the linear rails on this assembly as they will be doing nothing except add a bit more friction.

vacpress
04-30-2006, 06:20 PM
this looks very nice..

are those slides ebay finds?

paulC
04-30-2006, 07:01 PM
Looking good.
That is really solid.
Are you only running one rail along one side?
Paul

Rodm1954
04-30-2006, 08:26 PM
Vacpress
Yes the slides are Ebay items.

Paul
There will be two linear rails - one each side. I just popped the ballscrew assembly and one rail on the table for the photo.

paulC
04-30-2006, 08:44 PM
Paul
There will be two linear rails - one each side. I just popped the ballscrew assembly and one rail on the table for the photo.
Makes more sense to me now. I was missinterpriting one of your posts.
Your going to need to wear your steel caps when moving this puppy.
Paul

Rodm1954
05-07-2006, 06:13 AM
Perth was 22 degrees which is 72 degrees in our old currency :) so I wheeled the workbench outside and enjoyed the day. I had one of those days when you break taps and drill bits and put things down and can't find them but it was great being outdoors.
Oh yeah, it wasn't dream time all day and I did mange to get a bit of work done. During the week I stripped it down and shaped the steel a bit then sanded and painted. Assembly took a while as I had to make sure it was square. To make assembly easier I made up a few jigs out of MDF and used them as gauges.
I attached the X axis linear rails by tapping into the steel sides. So X axis is finished and next weekend I will make the aluminum gantry.
It was getting dark when I took the photo but you can see a bit of the garden setting I enjoyed all day.

Rodm1954
05-08-2006, 11:49 AM
A night in the shed and Y and Z axis are finished. I can't take any credit for the axis as they were purchased as complete assemblies but I did make the joining plate. :) Got to say this has been the easiest machine to build.
All I have to do is make a couple of sides for the gantry bolt this assembly to it and this machine is very close to being finished. I might even see some movement this weekend.

For those interested the X and Y axis travel is 400mm and the Z is 100mm. It is only a small machine but it will be ideal for engraving and decorative panels.
The rails on Y axis are 20mm and the rails on Z are 16mm. Ballscrews are 20mm pitch on X and Y and 10mm pitch on Z so it should be fast. I will try a direct couple with the motors but if the Nema 23 260oz motors aren't strong enough I have set it up to be able to retrofit pulleys. I will be running a Xylotex board and I have Mach3 and Vcarve software.

If you have a look at the first machine in this thread you will notice I have an engraved plate of the name of it on there. It is OBOTT which was a nickname given to me by a CNC group in Perth and it stands for "Our Brother of the Turnbuckle". If you look inside the base of that machine you will see I used turnbuckles to allign the sides. I have named this machine NOBOTT for the obvious reason that there is no turnbuckles on it. :)

Now before anybody says anything I promise to take my medication before I make my next post. :)

jb2060
05-08-2006, 07:51 PM
Hi Rod,

Very, very nice! This will be one fantastic machine.

well done so far.

cheers, Jason

Rodm1954
05-14-2006, 09:15 AM
Thanks Jason
Always nice to get some encouragement.

It is Mother’s day weekend so I was sure to cook the boss lunch and make the usual fuss. :)

I did manage to sneak out in the shed for a while and I have made good progress on the gantry. First I made a plate to connect the linear bearings. I cut the gantry sides and put a bit of shape into them and then assembled the gantry and Y and Z axis assemblies to it.

I just have the gantry sitting on the bench but I will lift it a bit and bolt a plate underneath that will pick up the X axis.

For something interesting yesterday I cut some dovetail templates out of 12mm MDF as a favor. I did them on my first router (Obott) and was pleased with the end product.

ger21
05-14-2006, 09:34 AM
That looks really nice.

Greolt
05-16-2006, 05:14 AM
Rod this looks like it is going to be a great machine and very accurate.

Your log on the ubeaut site is responsible for drawing my attention to the whole homebuilt CNC world.

I am now keen to build a machine and are gathering up bits and pieces.

Planning on similar in quality wise to your machines.

Probably with THK type rails. Cheap allthreads to get it going with then upgrading to acme or ball screws latter.
Thinking at this time to go for fixed gantry and moving x axis table about A4 size working area.

Anyhow keep up the log and I will follow your progress.

Greolt

LeeWay
05-16-2006, 06:47 AM
Good looking machines, Rod. I like the way the names occured as well. :)
Looks like this will certainly do what you need it to.
Look forward to seeing it in action.

Rodm1954
05-16-2006, 11:07 AM
Thanks Gerry and Lee. I hope it works. :) Greolt there are a few lurking from Ubeaut and Phillby has a build log on here. I have sent you a PM.

Tonight I finished off the gantry and connected X axis. First photo is the underside showing how I connected the gantry to the X axis ballscrew with a 100mm wide plate. The plate is just a piece of scrap but it is important to have a solid connection because it takes out the racking in the gantry. The bolt heads connecting the plate to the gantry are just rubbing on the table so I will have to either use countersunk screws or lift the machine a bit.

On this first assembly and with the ballscrew attached I can pull on the gantry and it moves freely along the entire length so the signs are good at this stage.

The other two photos are right side up and show some of the gantry detail. Next will be the table and I have been told of a good way to make it adjustable so I will try to incorporate it on this machine. If it doesn't work you will know in my next post. :rolleyes:

paulC
05-16-2006, 04:01 PM
Looking real good.
You've made quick progress and looks professional.
Paul

Rodm1954
05-17-2006, 05:39 AM
Thanks Paul
To be honest it hasn't been all that difficult because the ballscrew and slide assmeblies have helped. All I have done is put a bit of steel and aluminum around them.

Greolt
05-17-2006, 07:07 AM
Wow thats some pretty smicko gear you've got there Rod :rolleyes:

Sent you an email.

Greolt

Rodm1954
05-28-2006, 06:04 AM
Progress on Nobott (Son of Obott)

The second attempt at the table adjusters has worked well. I have attached steel flats to the underside of the MDF and have used a sort of push pull method. A thread in the flat bar allows a screw to push the bar upwards when turned. A second screw which is in a through hole into the frame is then used to lock it down. Probably best to look at the photos as it is hard to explain. What I have is a matrix of adjusters at close to 200mm centres so there is plenty of adjustment to get the table flat.

I also fitted some of those Ikea style knock down connectors that have a coarse thread on the outside and a 6mm thread on the inside. You screw them into the MDF with an allen key and I have found them ideal for clamping jobs to the table. See photo.

I made brass bushes to fit the couplings and motor shaft and then connected the motors to the mounts on the ballscrew. I also turned up aluminum knobs (wheels?) for the motors with a knurled section so that it is easier to manually move the axis. You need to purchase the motors with shafts extending out both ends to fit these. I find this handy particularly when setting up Z axis to zero on the material being cut. I cut and fitted a 12mm aluminum plate to the Z axis ready to mount the router.

The Xylotex driver board is mounted so with a bit of luck I will be able to fit the cables and see some movement this week.

Obott

While playing around with Nobott I ran a VCarve job on Obott. It was just a test to see if my vector conversion worked and the logo came out alright. It is on MDF and I have slapped some artist colour into the engraving to make it easier to see. I am impressed with VCarve as it uses a lot of Z axis movement to get the sharp corners. I used a ½ inch 90 degree V bit for the job.

Rodm1954
05-29-2006, 10:26 AM
Just a quick update. Connected the X axis up tonight and I still can't believe it but I got 15 metres a minute or in the old currency 590 inches a minute (I think). The 20mm ballscrews are the reason for this but it is quite unexpected as I thought the 260 oz steppers wouldn't have enough torque to drive it this quick.

I expected 2 metres maybe 3 tops but this has blown me away.

With only 400mm of travel the reflexes have to be quick to shut it off.
Surely you can't cut at this speed can you?

I will post later when the adrenalin has been adequately diluted. :cheers:

Greolt
05-30-2006, 12:34 AM
Won't loosing steps be an issue with that rate and those steppers?

I bet you end up gearing it down :)

Greolt

Rodm1954
05-30-2006, 08:16 AM
I got the Y and Z axis hooked up tonight. Interesting that Y could easily handle the same as X but Z could only :) manage 8.5 metres a minute.

The Z ballscrew is 10mm pitch which is half the X and Y pitch. It confirms what I have read on this forum that the steppers have all their torque down low and it drops off rapidly once the critical point is reached. The higher pitch of the X and Y axis produces the speed.
I have attached a short video of it air cutting the famous Mach3 roadrunner.
Hope you enjoy it.



Hi Greg
The machine is too fast for my liking anyway. :rolleyes: I have sent you a longer video so you can see it running. At 15 metres a minute the motors are strong but the bench needs to be beefed up a bit. :)

I am just a weekend shed nut so I am not qualified to make a prediction but my gut feeling is there is plenty of torque in these motors to deliver a respectable cutting speed without gearing.

I suppose part of the pleasure of building a CNC machine in the backyard is the trial and error - usually more of the later but sometimes you have a win. :)

Rodm1954
06-11-2006, 07:48 AM
A couple of weekends work and not a lot to show for it. These projects can be time consuming and the detail takes ages to complete.

Last weekend I made the trolley / bench to mount Nobott but I still have the hood and compartment to fit out for the computer and electronics. I made it all from salvaged material so it took a while to work around the defects.

This weekend I mounted Nobott and leveled the table with a dial gauge fixed to the Z axis. My adjustable table system did not work well and I ended up with dips between the fixing caused by stressing between the bolt pushing down and the through bolt holding it to the table. I ended up putting in another series of bolts between the fixings and I have now managed to get the table flat. I can't recommend this method as it really didn't work out as well as I planned it and it took ages to get it right.

I milled the mount for the router from aluminum blocks and have fitted it to Nobott. I ran a few trials at 300 inches per minute and the machine didn't miss a step. The router wasn't up to it though and I think it was dragged along rather than cut the path. Way too fast for my liking and I am glad I can slow it down through the software to a speed that doesn't raise my heart beat.

Just for fun I will capture some video of it cutting at this speed and post it here for those interested.

I still have to make the sound and vacuum hood, mount the computer and driver boxes and route the wiring.

ger21
06-11-2006, 08:56 AM
You should have no trouble cutting at 300-400ipm, but you'll need to take light passes (~3mm) so as not to overload the router spindle. At high speeds, for best results, use spiral upcut router bits, and not endmills made for metal. They cost a bit more, but should work much better. If you can get them, 3 flutes would be even better.

We use these. http://www.vortextool.com/standard/productDetail.cfm?groupID=264
If you buy 4 of the 1/4", you get a 30% discount. Don't know what the shipping would be to you, though. :)

Rodm1954
06-11-2006, 09:04 AM
Hi Gerry
It is more the operator that is the problem as I am used to cutting at much lower speeds on my first machine and I am not comfortable with the higher speeds yet.
Thanks for the tip on router bits.

Rodm1954
07-02-2006, 06:09 AM
Well I finally have got something to show.

I finished the sound hood and mounted it on Nobott. I spent all of today fitting the monitor, keyboard and routing the wiring. The wiring takes ages to clip down. I learnt from my first machine not to put the monitor and keyboard below the cutter or it becomes a dust magnet.

The cabinet is pine frame with 6mm MDF sheeting. Two acrylic windows on the side and at front and a third made from a diffuser to let a bit more light in.

Half of the top lifts up and there is full access at the front and a smaller door at the rear so I can still use long lengths on the machine.

It has reduced the noise of the router considerably so it hasn't been a waste of time. Now that I have the box on top I will have to work out a vacuum system as there won’t be much escaping out of that cabinet. :)

Rodm1954
07-10-2006, 08:16 AM
I made the vacuum attachment using my first router Obott to machine some aluminum.

The first photo shows the plate after machining and the port connecting the two chambers.

Photo 2 and 3 shows the unit assembled and photo 4 shows how it will fit to the router mounting (minus the clamp). It works very well and thanks for the idea from the collection of posts on this forum.

Well that is Nobott finished. Obott has hundreds of hours of cutting on the clock and is holding up well so I hope this one is as robust and reliable.

I have really got the bug on building these machines and number three will be started this weekend. I already have all the rails and ballscrews and a design in mind for an X of 300mm, Y of 200mm and Z of 75mm. A small unit I can sit on the computer table inside and play with.

Thanks for all the positive comments and encouragement and see you shortly on a new thread with machine number three. In the tradition of my machine naming convention I have chosen Jabott for the next router. Just Another Brother Of The Turnbuckle. :)

diarmaid
07-10-2006, 11:49 AM
Well done & great build Rod. Looking forward to the info on Jabott! :) L8rs.

epineh
07-11-2006, 05:13 AM
Nice work Rod.

Russell.

Rodm1954
07-11-2006, 06:00 AM
Thanks for the comments.

It is good to be able to contribute somethig to the forum as I would not have had the confidence to start without the knowledge I got from here in the first place.

paulC
07-11-2006, 08:54 PM
Love the vacuum attachment.
I keep thinking about using brushes as part of a solution, but what you have done would be much simpler. If you don't mind I have a few questions.
What are you sucking with? a shop vacuum? How high above the workpiece does it continue to collect dust? Does it hinder bit changes?
That Ozito router is similar to the one I'm using on my second machine. Are you happy with only one clamp at the neck? I was thinking of a second clamp higher up around the body of the router but it would, of course, save time and effort if its not required.

Paul

Rodm1954
07-12-2006, 02:05 AM
Hi Paul
Yes using a shop vacuum. There is not much suction 25mm out from the port but I expected that. The diameter of the port is about the same as the hose so the suction is similar. I haven't fitted it up properly yet but I expect to have to use a brush. I will mount it permanently to the underside of the router mount as I can still get a spanner on the shaft.

I will be relying on the brush to bridge the gap. The brush will be designed to be quickly detached (rare earth magnets?) otherwise it will not get used. I have tried for two nights using search on this forum to find the link to a supplier but no luck yet. I was sure I saw a post about it somewhere.

The router mounting is a 20mm thick block and provides ample support. I was in a hurry when I machined that vacuum port and I cut it at 1200mm/minute and 3mm deep cut by mistake. The only thing that looked like failing was the under powered router itself so I am happy with the mounting.

rpage
07-12-2006, 11:54 AM
nice table! wish you had plans for this one. I have a plasma table and could cut most of the parts :)

Looks really nice!

paulC
07-12-2006, 05:06 PM
I will be relying on the brush to bridge the gap. The brush will be designed to be quickly detached (rare earth magnets?) otherwise it will not get used. I have tried for two nights using search on this forum to find the link to a supplier but no luck yet. I was sure I saw a post about it somewhere.


I saw a link somewhere too. Can't find it but found this:
http://www.mcmaster.com/
Search for Conveyor strip Brushes
Must be plenty of suppliers in Australia though.
I'm using some brush from a draft stop at the moment. The bristles are a bit short but better than nothing.
Paul

paulC
07-12-2006, 05:59 PM
The router mounting is a 20mm thick block and provides ample support. I was in a hurry when I machined that vacuum port and I cut it at 1200mm/minute and 3mm deep cut by mistake. The only thing that looked like failing was the under powered router itself so I am happy with the mounting.

Just out of curiosity how do you cut aluminium?
I cut 150mm/min 0.5mm deep with a spiral upcut bit and compressed air for cooling and chip removal. Never sure how fast to push it so would be interested to know if you are going faster.

I broke a 3mm bit when I cut 3mm deep by mistake. :(
Thats what I get for trying to be clever and using variables and M98 subroutines. I tripple check now.

Paul

Rodm1954
07-12-2006, 08:27 PM
Hi Rpage,
Sorry I don't have plans. I prefer to be in the workshop than behind a computer so it is usually measure and fit as I go. :)

Hi Paul,
Thanks for the link. I have found aluminum unprectictable and mainly due to getting a lot of mine from scrap merchants. I use carbide two flute mill cutters and have broken a lot of them finding the right feed rate. It is funny as they will sometimes handle one job fine and then the next job they snap half way through the job. I can only put this down to poor material and gumming up of the bit but I am not an expert.
250mm/min cutting speed and 0.5 mm cutting depth is pretty much the starting point for the 3mm bits. I spray WD40 on the job as I go but it does take a while to clean up afterwards. I put a cover sheet on the table to protect the table top. The vacuum port I used a 1/4 inch carbide mill cutter because there were no sharp inside corners and it was quicker to cut the pocket with the wider bit.

paulC
07-12-2006, 09:47 PM
Hi Rpage,
I use carbide two flute mill cutters and have broken a lot of them finding the right feed rate. It is funny as they will sometimes handle one job fine and then the next job they snap half way through the job. I can only put this down to poor material and gumming up of the bit but I am not an expert.


I was using wd40 at the start but switched to compressed air. The secret is not recutting chips, you really have to get them out of there when running a router or they melt and bind to the cutter, then bang its broken. You also don't get the problems with oil every where, but my wife is about to kill me for trapsing aluminium flakes through the house every time I go in from my garage. I also get a much cleaner cut. Give it a go and tell me what you think.
The problem I have at the moment is standing with a compressed air duster gun for long periods. I need to strap it in place on the machine pointed at the cutting area somehow.
Paul

ZipSnipe
07-12-2006, 10:50 PM
Truly inspirational Rod, nice, very nice!!!!

rpage
07-12-2006, 11:44 PM
bummer :( very nice looking machine, you do nice work!

Rodm1954
07-13-2006, 05:27 AM
Thanks Zipsnipe and Rpage :cheers:

Paul,
I am glad I am not the only one getting into trouble for spreading aluminum glitter everywhere. :)
I'll try the air and see how it goes as what you describe it exactly what is happening to me.
Trick to overcome is how to use compressed air and vacuum at the same time. I had intended to hook a 4 inch port to the sound hood and use my dust extractor but I was told the chamber was too big for it to work so that is why I went for the shop vac. At least it will all be contained in the sound hood on this machine so I am part way there.

Rodm1954
07-16-2006, 07:04 AM
The vacuum attachment was not working as well as I wanted so I made an adjustable mounting so that it could be placed closer to the cutter.
See photos for details.

les99
07-16-2006, 12:25 PM
Very nice Rodm, I'm seriously thinking of doing something like this myself. What level of accuracy do you get with your first machine?

Rodm1954
07-16-2006, 08:54 PM
Hi Les,
I am sorry but I can't give you a tolerance as I have never measured a part after making it. I know it is very accurate as the parts I have made have fitted perfectly such as the tube in the vacuum head and dovetail template.
Repeatability is excellent as multi pass cuts do not show any visable deviation in the job.
I don't think it is as good as a commercial mill but for the work I do it is far more accurate than I can make.

CNCfun&games
07-11-2008, 09:04 PM
Hi Rod,

This is some great stuff. Sorry I missed the first showing!!
Just discovered this thread today. Have been researching routers
and found your project!

Looks like you are an expert on V Carve too!

Got hung up around the Bridgerort Forums & missed all the real fun.

The way you incorporated the vacuum attachment into the Z axis is
fantastic. Nice bit of machining also....
Regards....W. Smith

Rodm1954
07-12-2008, 12:14 AM
Hi CNCfun&games,
I didn't realise I have been making machines for as long as I have. :eek:
I have lost count of the number of machines I have built now but it must be over ten and I am still learning new ways of doing it.
I still have my first machine but have rebuilt bits of it along the way. I don't think I will ever get rid of that one as it has that sentimental value. :)
Vectric is excellent software and very easy to get started with. It has done all my machining designs and recently I got the Cut3D sodtware. I can highly recommend their product.
Funny as I have changed my habits too and hang out in the mill threads. :) Your casting work over there is outstanding and somerhing I can only dream about for now.

CNCfun&games
07-12-2008, 06:43 PM
Hi Rod,
Have you used a Rack & Pinion Drive on any of your Routers?
My first moving gantry machine has 54" X travel & don't know
if any speed above 150 IPM is even necessary. What do you think?

Will probably also use V Carve on this machine.

The machine is configured like this.......

W. Smith

Rodm1954
07-12-2008, 10:19 PM
Hi CNCfun&games,
I haven't installed rack and pinion myself but have played around with a couple of commercial machines that have had it fitted. It seems to work well and elimates racking compared to a central ballscrew.
Speed is good but it tends to be over rated sometimes. Unless you fit an expensive high powered high speed spindle you can only use the extra speed for rapids. High rapid speed is great but there are limits becuase of the intertia created by the high speed and sudden stop. Generally you have to slow the acceleration down so if you are doing short rapid moves as in carving you really don't get the full benefit of the highest speed. If you are doing a rapid move from one end of the machine to the other then obviously it will count so it depends on what type of job you do as to the gains.
150in/min is quite respectable and in the range that should not be affected too much by what I describe above.
The little machine in this thread was very quick and I ended up slowing it down in the motor tuning because I could not react quick enough when something went wrong. Age tends to do that to us. :(
I like your design and don't be tempted to fill in the sides. There is a lot to be gained in set up time if you can cross clamp on the table.

CNCfun&games
07-13-2008, 05:35 PM
Rod,


Had not thought about the clamping problems associated with enclosing the sides.
I made the X axis 54” so I could slip a 4’ x 8’ sheet of plywood in under the gantry
and engrave the whole thing in 2 passes. I also made a note of your experience in
leveling the bed and will try to address the adjustability problem .

Appreciate your input: You are saving me a lot of headaches!!

W. Smith