[complete] 3-axis CNC router

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rsilk
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Joined: Wed Dec 01, 2010 11:55 am

[complete] 3-axis CNC router

Post by rsilk » Sat Dec 11, 2010 11:34 pm

My main project last winter was this guy - a 3-axis CNC router. The idea is to take a standard off-the-shelf wood router and move it in 3 dimensions under computer control to carve out stuff. CAM software converts standard CAD drawings or vector images into a series of toolpath instructions (move to xyz, etc) in a language called G-code. That gets fed into control software which reads the G-code and spits out step and direction pulses on the parallel port to drive the stepper motors on the axes.

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More pictures here: http://www.flickr.com/photos/56956316@N ... 579909196/

A video of the machine routing a test circuit board: http://www.youtube.com/watch?v=1aDL3KjyMjY

FingerTech
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Location: Saskatoon, SK.
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Re: [complete] 3-axis CNC router

Post by FingerTech » Sun Dec 12, 2010 12:46 am

Very nice machine! Great to see you can get such precision from MDF construction. Was the circuitry from a kit or your own?

rsilk
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Re: [complete] 3-axis CNC router

Post by rsilk » Sun Dec 12, 2010 12:08 pm

It has a bit more flex than I'm happy with, but I think that's due to the way I built the axis carriages. Once it warms up I've got a few mods to make which should stiffen it up some more. The driver board itself was a kit from hobbycnc.com, but I scratch-built the (very basic) power supply.

mattf
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Re: [complete] 3-axis CNC router

Post by mattf » Thu Dec 16, 2010 4:21 pm

very cool!
Are you using emc2 or Mach3?

What tool did you use for isolation routing? Where did you buy it? Did it require much cleaning up a after?

Here is the only PCB I have milled (it required a fair bit of cleaning up the ragged edges of the traces):
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It's a breakout shield for an arduino to connect servos, serial, bluetooth and LCD:
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I did it on my converted harbour freight special:
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-Matt

rsilk
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Re: [complete] 3-axis CNC router

Post by rsilk » Thu Dec 16, 2010 4:38 pm

I'm using mach3 to drive it at the moment. I used a tiny little engraving bit from precisebits.com to do the milling. That's mounted into an aftermarket 1/8" collet (also from precisebits) on a bosch colt trim router. That was a while ago, but I don't remember it needing too much cleaning up. A quick scrub with some steel wool cleaned up the jaggies. Looks like you've got quite a bit more accuracy on your mill, which is not too surprising. I'm still dealing with some flex and backlash issues.

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DigitalOSH
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Re: [complete] 3-axis CNC router

Post by DigitalOSH » Fri Dec 17, 2010 1:00 am

Just jumping in completely uneducated here, but what's causing your flex issues?

rsilk
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Re: [complete] 3-axis CNC router

Post by rsilk » Fri Dec 17, 2010 1:20 am

A weak design on the axis carriages, mostly. This image shows it pretty well in the y axis -- there's not a whole lot to keep the top and bottom pieces from racking. I probably need to make a C-shaped piece that wraps around the leadscrew and connects to those pieces to keep them square. The other source of flex is that MDF just isn't as rigid as it looks. I should be able to reinforce some of the longer pieces to compensate for that.

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Odemia
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Re: [complete] 3-axis CNC router

Post by Odemia » Tue Jan 11, 2011 10:32 pm

Beautiful!!!

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