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Small CNC Machine help?!! Answered

Looking into building a CNC maybe 15 x 20 inches working area, and need help:O Ive seen several instructables about it but still not sure which type of motors to use and why, where to buy the circuitboard OR how to program a DIY one, what are the 4th and 5th axes, and will it be expensive? Also are there any other hazards i should think about during the build? Any help would be greatly apprecited, thanks.



Best Answer 9 years ago

I'm a programmer and I always favor the progressive methods of development. I would advise: Arduino, Modified servos and some draw sliders. Once you have an x/y table you can implement a foam cutter or such and progress on from there. It's something I have been meaning to do but always seem short on either time or parts. If you go down the stepper motor road you need additional circuitry and things making it a little more complex. Sticking with the Arduino idea there is a motor control board that can be literally plugged into the top which I believe would be suitable. What I find a problem is that the USB connection is via a virtual com port, which means it doesn't appear as a USB gadget. On a practical level I don't think its a problem. Also, failing that there is of course the Make controller, and a variety of other platforms (These two are the ones that come to mind at the moment) Motors: Servo's are cheap and easy to interact with, Stepper motors less so. Servo's would probably be quite imprecise but i have seen implementations that look okay (You'd probably want a servo modified for continuous rotation connected to a threaded bolt to move the x/y table), stepper motors are a lot more precise, in that rotation can be controlled in fractions of a rotation, normally 3,4 or some multiple thereof. Control: You probably want a USB/Serial computer connection for control purposes, the aforementioned Arduino and Make controller have this functionality. Implementation: Just go with a nice simple solution. The slider components from draws look okay as a first attempt solution. A long bolt connected to a servo and a nut (unable to rotate) fixed to the slider is the easiest way i can think for simple linear motion with a degree of control. try using a heating strip to cut foam, or even a pen to draw out shapes (at first) to get something running. Just go easy, get something simple running and either modify it or reuse the components and make progressively better designs based thereon. Hope this helps, Drew

3axis is enough, thats left and right, up and down and to the front and back. With more axis you will make it TOO complex! Don't do that. Start with 3 axis and then you'll understand why I told you not to work with more.

Just start with the 3-axis, possibly even 2-axis, and work up from there.