I found some instructions for calibrating machines that said to use a movement gauge and I don't have one
I do have a cheapie digital calipers, though.
I was thinking, if I have 10-15 parts in the 4" or 6" square range and they are all consistently undersized, and I calculate the difference in the size I actually got, and the size I anticipated, couldn't I just compute an adjustment to the "steps per" unit for that axis?
I realize this wouldn't be ideal, as I'm including any error in the spindle and the bit I'm using, but the parts I'm getting are pretty consistently undersized by approx. .01" per 4" using two different routers and two different bits now.
Any other suggestions?