Build Your Own CNC

Build Your Own CNC Building your own low-cost CNC (computer numerical control) machine is easier than ever, thanks to free software available today, according to Jim Wilson and Gregg Carlson, retired extension educators. They’ve built CNC plasma torch tables and a CNC-guided wood lathe. “When I look at FARM SHOW subscribers, I expect 15 to 20% could build a CNC table and make a business out of it,” says Carlson. “Anybody with a farm shop could fabricate a table. Whether salvage or new, a CNC table will cost you less than $200.” “The stepper motor, controllers and power supplies run less than $300 for the CNC itself,” says Wilson. “Compared to a commercial CNC machine, that’s chicken feed. The things you can do with it are incredible. The cost is almost nothing. CNC tables need to be available to any maker.” When Wilson and Carlson aren’t using their own CNC machines, they teach vocational agriculture instructors how to build and operate their own, and they pass on their knowledge. Carlson got the bug when he bought a small, commercially available CNC router more than 15 years ago. It impressed him enough that he decided to build his own table. Along the way, he discovered how inexpensive the components are, how to access free software online, and helpful paid software packages. “I use both free and paid software, but you can build all kinds of things with free software,” says Carlson. “The first thing is to assemble and build the hardware. The second concern is learning the software.” Carlson has assembled a series of PowerPoint “cookbooks” that outline the steps to follow. He and Wilson are seeking ways to make them available for download in digital format. One example of the simple components needed for one of their tables is roller skate bearings. “They’re the heart and soul of the table,” says Carlson. “We built a frame for them to run on.” The bearings allow the tool to move back and forth across the table and up and down along its length. The hardware needed for the CNC consists of an Arduino microcontroller ($10 to $26), a stepper motor, and a converter and controllers. The controllers tell the stepper motor how far to turn (travel on the table), in millimeters or thousandths of an inch, for accuracy. When a friend asked whether they could adapt CNC for his wood laser, they responded, “Why not?” It’s since been used to produce spiral legs for Wilson’s new dining room table and wood gears for an all-wood clock. “Using a freeware program, I wrote a program to cut the wooden sprockets,” says Wilson. “That’s the kind of stuff you can do with this,” says Carlson. “It’s so powerful. With free software like Library CAD, you can take an idea and put it into code.” Wilson and Carlson haven’t stopped at CNC for routers, plasma cutters or lathes. “We each just bought CNC-ready laser engravers for only $130,” says Wilson. “The resolution is phenomenal. A lot of this stuff can be done very inexpensively.” Contact: FARM SHOW Followup, Gregg Carlson, Brookings, S.D. (gregg.carlson@sdstate.edu) or Jim Wilson, Bruce, S.D. (jrwltd@itctel.com).

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