# Yet another Homebuilt CNC Router



## geotek (Mar 4, 2012)

I built this machine to replace the 6040 type machine I had been using. I built it for high precision, so that I can mechanically etch circuit boards as well as more normal woodworking tasks. One end of the table has an apron where workpieces may be attached for routing on the ends. The gantry of the machine can be remounted about 6" from its normal position, allowing the spindle to overhang the end of the bed by up to 3".
The machine uses 5mm pitch ballscrews, which tend to limit travel speeds, more enhances accuracy and stiffness.

Snapshots of the machine:



















Here's a somewhat boring video of it doing some V-Carve work:
Home Made CNC Router - YouTube


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## geotek (Mar 4, 2012)

I've had a few questions about where to finds the kit, etc. This machine was built from scratch. I got the ball screws, slides, and electronics from vendors on eBay, but all the mechanical parts were machined in my shop. The machine was pretty much designed around material I had on hand. If you look real close at the end plate where the Y-axis motor is mounted, you can see a date code on the aluminum of April 1999. 

Things I would consider changing are: I thing it would have been better to use ball screws of 10mm pitch for the X and Y. To get 100"/min, my motors must run at 500RPM, which can lead to resonance problems. I would also have used NEMA-34 motors for the X and Y. The longer lead would require more torque. 

I have now run some tests on machining printed circuit boards, and it is very precise. This was one of my major goals. The speed is only an issue because if I have to traverse the entire 48", at 80"/min it seems to take forever. 

Improvements: I think the first thing I will do is swap out the 1.5KW spindle and replace it with a 2.2KW spindle. When I built the machine I had a spare 1.5KW unit sitting around, so that's why I used it. The VFD is rated for 2.2KW, so I'm all set. I don't need the power, but the step from a 1/4" collet to a 1/2" collet would be very helpful.

One other thing. The name RoboChop came from a project I started about 25 years ago. At the time I wanted to build a CNC plasma cutter. I didn't get very far. Parts seemed much harder to get back then. The move Robo Cop was popular, so I thought the name RoboChop would be good. I still like it.


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## jlord (Nov 16, 2009)

Nice machine.


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## jlord (Nov 16, 2009)

What size is the table? 

How much would you estimate the cost to build machine to be?


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## geotek (Mar 4, 2012)

The table is 31.5 x 57", the travel is 27 x 48.5".
The cost, the parts I purchased probably came to almost $2K, but it you had to price out the 200# of aluminum and all the machine work, the would add up quite a bit.


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## jlord (Nov 16, 2009)

Thanks, George.
It looks like a well put together machine.


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## NonCnfrmstsUnite (May 28, 2013)

*Home-built CNC machine firmware?*

This is a really awesome machine! I read that you got the electronics from ebay. Did the controller board you used already have router firmware on it, or did you have to find or write your own and upload it? What firmware are you using?


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## geotek (Mar 4, 2012)

No firmware needed. This machine is run by Mach3, Mach3 is a program that produces all the direction and step pulses through the parallel port of a PC. All that is needed is a computer running XP, a breakout board, and some stepper motor drivers. My previous machine used a Gecko G540 which has the breakout and four axis of drivers all built into a single package. 
Thanks to Mach3, the electronics is very simple.


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## laurent_parti (May 15, 2013)

Nice machine, congratulations !


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