I want to build a CNC router that will cut foam, balsa and depron of at least 6mm in width. I would also like it to cut lite ply up to 1/8" in width. I would like the cutting surface to be 24" x 36". I would like to use a high quality trim router or similar for the cutter.

Now I have searched ezone and the web for the last year or so on and off looking for the right machine. Everything I have found so far has too small a cutting surface and there are always warnings about don't try and scale up the design or use larger cutting tools.

Can anyone point me in the right direction for plans or a kit for a cnc router that will do what I want above? I don't want to break the bank on a commercial machine at this time but I don't have any problems with a modest investment (up to $1000 USD) UPDATED: I realize now that this figure isn't in the ball park... please disregard it.

Thanks,
Brendin

Try this Group
Yahoo Group CNC

I have a CNC foam cutter now and working on a 3D machine now.

Originally Posted by Xnaron

I want to build a CNC router that will cut foam, balsa and depron of at least 6mm in width. I would also like it to cut lite ply up to 1/8" in width. I would like the cutting surface to be 24" x 36". I would like to use a high quality trim router or similar for the cutter.

Now I have searched ezone and the web for the last year or so on and off looking for the right machine. Everything I have found so far has too small a cutting surface and there are always warnings about don't try and scale up the design or use larger cutting tools.

Can anyone point me in the right direction for plans or a kit for a cnc router that will do what I want above? I don't want to break the bank on a commercial machine at this time but I don't have any problems with a modest investment (up to $1000 USD)

Thanks,
Brendin

For a $1,000USD you'll need to design the machine yourself and drive it with all thread at a whopping 20IPM, if you're lucky. Figure out how long it would take to cut out a "foamy" at that speed! Heck, "real" leadscrews will be $400USD alone. CNC electronics are gonna add $400 more at the least. You'll bearing of some kind too! Check those out on eBay? Ouch!
Keep us posted if you decide to do it yourself or find a planset.

Dave

I quote from "Somethings got to Give". "We all want that dear. It doesn't exist".
If you double your amount, you may get close. If you make it yourself, you can possibly do it but you will need some luck in finding items cheap.

A machine as long and wide as you describe will have to be very rigid/heavy. MDF based machine will flex if built this long. Therefore a reinforced bed is needed. That means steel or Aluminum.

Don't be discouraged. You can do it. But be prepared to spend.


Bill

Originally Posted by HobbyCNC

For a $1,000USD you'll need to design the machine yourself and drive it with all thread at a whopping 20IPM, if you're lucky. Figure out how long it would take to cut out a "foamy" at that speed! Heck, "real" leadscrews will be $400USD alone. CNC electronics are gonna add $400 more at the least. You'll bearing of some kind too! Check those out on eBay? Ouch!
Keep us posted if you decide to do it yourself or find a planset.

Dave

I was just grabbing a figure out of the air...whatever the price doesn't matter all that much. I shouldn't have even posted a figure. I wasn't sure if I needed "real" lead screws. I suppose the resolution should be close to 0.0001". I didn't think the CNC electronics would be much more than $200 Dave... I guess the ones on your site won't work for a machine of this size then. I already have the PC and ATX power supply to run the electronics.

Ok let me post my question again and this time please do not take into account the price figure above. I am just looking for plans or a kit.

Brendin

Originally Posted by bgriggs

I quote from "Somethings got to Give". "We all want that dear. It doesn't exist".
If you double your amount, you may get close. If you make it yourself, you can possibly do it but you will need some luck in finding items cheap.

A machine as long and wide as you describe will have to be very rigid/heavy. MDF based machine will flex if built this long. Therefore a reinforced bed is needed. That means steel or Aluminum.

Don't be discouraged. You can do it. But be prepared to spend.


Bill

Yes...as I said I shouldn't have quoted a dollar figure...The fact is I have decided to build one and the money doesn't really matter at this point. I can weld a table up and put it on wheels... I already have the PC and ATX power supply to run the electronics. I have compressed air and vacuum (ghast pump) in my shop. It sounds like I am going to have to take a closer look at what is out there and engineer a modification of an existing design. I am also looking into buying a built table at this time as well.

Thanks,
Brendin

Originally Posted by Xnaron

I was just grabbing a figure out of the air...whatever the price doesn't matter all that much. I shouldn't have even posted a figure. I wasn't sure if I needed "real" lead screws. I suppose the resolution should be close to 0.0001". I didn't think the CNC electronics would be much more than $200 Dave... I guess the ones on your site won't work for a machine of this size then. I already have the PC and ATX power supply to run the electronics.

Ok let me post my question again and this time please do not take into account the price figure above. I am just looking for plans or a kit.

Brendin

Our 3 axis 80oz-in package will not be "strong" enough. Even if it was, the $170 purchase price will still need to be added to for the transformer ($50USD) and a case ($30USD). @ $250 plus shipping charges will bring it close to $300. You'll need 125oz-in minimum, 187oz-in MUCH better. On your resolution of .0001", I'd be looking at something closer to .001".
Real leadscrews (not necessarily ball screws) are the only way to get decent speed for a router with 36" of travel.

Dave Rigotti

Originally Posted by HobbyCNC

Our 3 axis 80oz-in package will not be "strong" enough. Even if it was, the $170 purchase price will still need to be added to for the transformer ($50USD) and a case ($30USD). @ $250 plus shipping charges will bring it close to $300. You'll need 125oz-in minimum, 187oz-in MUCH better. On your resolution of .0001", I'd be looking at something closer to .001".
Real leadscrews (not necessarily ball screws) are the only way to get decent speed for a router with 36" of travel.

Dave Rigotti

Thanks Dave. Is your driver board designed to drive heavier than 80oz-in steppers? I just spent some time on ebay looking at linear slides and leadscrews... there is a fair amount to look at.

Found this HDPE design http://members.cox.net/walachcnc/plastic.htm

Does anyone know of a good source to buy the "true" or "real" leadscrews?? I'm in the same boat as Xnaron is and would like to DIY a larger unit for cutting Depron and Balsa.
Also, how much would one expect to pay for 200oz-in stepper motors?? <$75??
Would this stepper motor http://cgi.ebay.com/ws/eBayISAPI.dll...856922163&rd=1 be sufficient??

Thanks ain advance

Originally Posted by mrbaseballny

Does anyone know of a good source to buy the "true" or "real" leadscrews?? I'm in the same boat as Xnaron is and would like to DIY a larger unit for cutting Depron and Balsa.
Also, how much would one expect to pay for 200oz-in stepper motors?? <$75??
Would this stepper motor http://cgi.ebay.com/ws/eBayISAPI.dll...856922163&rd=1 be sufficient??

Thanks ain advance

Those are nice motors, but you will need gecko drives to drive them. www.geckodrive.com

Eric

Originally Posted by Xnaron

Thanks Dave. Is your driver board designed to drive heavier than 80oz-in steppers? I just spent some time on ebay looking at linear slides and leadscrews... there is a fair amount to look at.

Found this HDPE design http://members.cox.net/walachcnc/plastic.htm

"Size don't matter!"
3A per coil does.

Dave Rigotti

my router is 48" x 30" with 5" of z travel. I am using Nook ball screws for the the y and x axis. for a 5/8" dia ball screw .200 lead 4' long with the nut is approximately $100.00. I purchased my ball screws from www.reidtool.com. I just upgraded to a trim router on my system from a Dremel. I orginally used thomson rod and bearings and found that I was getting to much flex. I have since upgraded to THk rails. I am running Hobbycnc 125oz package. I am able to cut at 40 ipm. I have cut 3/4" baltic birch plywood in muliple passes approximate depth per cut .100". I have less than $1000.00 in my machine.

so I would say it is possible.

Rich

Originally Posted by balsaman

Those are nice motors, but you will need gecko drives to drive them. www.geckodrive.com

Eric

So one Gecko G210 Driver per axis right? Then I need a controller to provide the geckos with step and direction pulses... Any suggestions for what would work well with the geckos?

Thanks,
Brendin

Originally Posted by planeflier

my router is 48" x 30" with 5" of z travel. I am using Nook ball screws for the the y and x axis. for a 5/8" dia ball screw .200 lead 4' long with the nut is approximately $100.00. I purchased my ball screws from www.reidtool.com. I just upgraded to a trim router on my system from a Dremel. I orginally used thomson rod and bearings and found that I was getting to much flex. I have since upgraded to THk rails. I am running Hobbycnc 125oz package. I am able to cut at 40 ipm. I have cut 3/4" baltic birch plywood in muliple passes approximate depth per cut .100". I have less than $1000.00 in my machine.

so I would say it is possible.

Rich

Thanks for the link Rich... Very helpfull... Do you have any pics of your machine you could post?

Thanks,

Brendin

From Nook lead ball screw spec
"All ball screws are right hand thread. Made of high quality alloy steel, induction hardened
to RC 56-60. Flanges and nuts are made of carburized steel with ball tracks heat treated to RC 58-
60. Both ball screws and nuts have a protective black oxide finish. Ball screws will not deviate from
nominal lead by more than .004 inch per foot."

The last sentence " Ball screws will not deviate from
nominal lead by more than .004 inch per foot" ... What exactly does this mean? For every foot it travels it is withing + or - 0.004"?

Thanks,
Brendin