Desktop CNC Router

[cfellows]

For a long time I've been contemplating building a small CNC Router.  I've never started one because I already have a CNC milling machine and didn't see the point.  However, I ran across this little gem recently, and it is so darn cute, I decided to build one just for the fun of it.

http://makeyourbot.wikidot.com/mantis9-1

The original has an overall footprint of 10" x 10" and a work envelope of something like 7.5 x 4.5 x 2 or so.  It uses 3/8" hardened shafts and bronze bushings for the linear rails.  It's dirt simple to build and uses some rather unusual  (and cheap) methods for fastening things together.  Looks like it could be built with nothing but a table saw and drill press.

Mine will be a little bigger, having a 12" x 12" footprint with 1/2" hardened shafting for the rails.  And, since I have machine tools, I will employ them where I can to make things a little more accurate and rigid.  I do, however, plan to follow the original idea of keeping it simple and cheap.

I've ordered the shafting and bronze bushings from McMaster and have cut out the frame from 1/2" baltic birch...



I spent a lot of time getting everything as exact and square as I could.  Should make things easier later on. 

Chuck

[Brass_Machine]

Hi Chuck

I will be watching this one. Very interested in building a CNC router myself. Probably a couple of them really.

Eric

[dawesy]

Looks likes good project. Watching with interest

[Rubes]

Hmmm...if you make the sides full sized, rather than the "L" shape, then just make a slot along where the table moves, it would allow you to do longer pieces.
Looks like a fun little project.

[cfellows]

So after some noodling I've settled on some design details and been slowly putting some things together.  Here's what I've got so far.



The overall footprint is 12" x 12".  The rails are 1/2" hardened shafting.  The bearing assemblies are made up of 1/2" ID x 5/8" OD, graphite impregnated bronze bushings pressed into short lengths of electrical conduit.  The conduit was probably not a good choice since tolerances on diameter, roundness, and straightness leave a lot to be desired.  But, in these short lengths, it works pretty well.



The leadscrews are 1/2" x 10tpi acme threaded rod.  The nuts are made from 3/4" diameter delrin drilled and tapped to 1/2 x 10TPI and pressed into 7/8" OD aluminum tubes.



I also received my 400 watt, air cooled spindle motor.  I'm pleasantly surprised with how little noise and vibration the motor has.

Chuck

[backofanenvelope]

Sitting quietly at the back of the room, looking forward to seeing this progress..
Tom

[vtsteam]

Chuck, It looks like the conduit covered linear bearings are shorter in some photos than others. Is it that they are different for X and Y? How much travel will you have left after allowing for the bearing lengths?

I'm liking this build and your nut and bearing methods.

[gmac]

Hi Chuck;
I'll be following this one! I've been looking at these desktop routers thinking it would be a cheap, simple way to getting into CNC. I considered building either the MYDIYCNC Sprite or the Shapeco (rather than buying a kit, just make something similar myself);

http://www.mydiycnc.com/content/new-sprite-desktop-cnc-machine-turnkey-system
http://www.mydiycnc.com/sites/default/files/MyDIYCNC%20Desktop%20CNC%20Machine%20Kit%20Assembly%20Instructions.pdf

http://docs.shapeoko.com/

After pricing materials, I concluded that maybe the money was better spent on materials to convert my X2 mill to CNC. I'd be interested in your comments/findings on each path - before I go and do something stupid !

Good luck with the project.

Cheers Garry

[Joules]

Go for STUPID Garry, thats what makes life interesting.  Nice thread Chuck look forward to your documented guide.