Question Oblong Circles

Hi,

I am trying to cut out some small washers/flanges out of acetal, dia. 14mm. However, the circles are coming out a little mishapen. At a guess, the Y axis stopped for second and the X continued so there's a little straight section but I have cut out a second set, changing material position and zero positions etc. and get the same issue. Hoping someone else has encountered this before and has a solution or possible solutions thanks.

Hi Evan,

This could well be due to your backlash settings being incorrect - are you using UCCNC and UC100 to drive your machine?

The correct setting are quite difficult to achieve because you are looking for errors of the order of a few 10's of microns - I was fortunate enough to have a small microscope with a calibrated graticule to view some test patterns.

Peter

more likely that the headless set screw or the pulley that drives the tread might be loose:

Evan check this too: https://www.stepcraft-systems.com/en/servie-and-support/stepcraft-forum-uk/software2/2307-difference-between-constant-mode-and-exact-mode

If you want full precission, go with Exact Mode.

Thanks jvalencia, I changed to Exact Stop mode on UCCNC and has made an improvement on the 'roundness' of the circle but looks like it might indeed be the backlash as the errors would be at the points of axis reversal. A bit more tinkering to do, thanks for all your help.