I have a small K2 CNC desktop machine I use very occasionally.
I use Mach3 to drive a Xylotex driver, I create my files w/ Cut2D these days. I'm using a USB stepper into the parallel port of the Xylotex.
I use a circle in a piece of ply that is 9.0625". The ply is .5", I took .125" bites (climbing) and did a .001" final pass (reversing).
In my X axis, I think I'm very close to 9.0625" (maybe .003" over or so which for my applications is plenty close).
In my Y axis, I'm a little under, maybe .01". Still usable for my speaker-building stuff, just wondering if it could be better.
But the circle is slightly elliptical and I'm wondering if I could get it better.
This machine has acme screws and I guess my question is, is it possible that one acme screw could be .01" off over 9"? Or is that pretty unheard of.
Any suggestions on where to look for a problem like this. I'd love to find a FAQ on making final adjustments/dialing-in a machine, if there is one.
I have a dial indicator that resolves to .001" and has about 1" of travel. I also have digital calipers in 6" and 12" lengths.