[IpsoFacto]

I'm running a ViperXZ with a PC 890 & Super P.I.D.

I'm cutting a simple part out of MDF with a pocket around .6 deep. The problem: every depth I cut the pocket at seems to have "shifted" by about .2!
So it looks like the pocket has steps on one side and fine on the other.

Has anyone encountered anything like this? I'm programming my paths in X4 and controlling my machine with Mach3.

Thanks!

[kevincnc]

Sounds like your spindle is not square. Have you ever trammed it? Did you mean shifted .02" or .002", not .2"? If .2 you much have another problem.

[IpsoFacto]

That's the thing, my spindle is square and the shift is 0.2! Looks like something else altogether... I'm really scratching my head over this one. I'm going to try cutting the same pocket today and see what happens.

[ger21]

Do you mean the X or Y axis have shifted? If so, I'd remove the motors and turn the screws by hand to check for binding anywhere. If there's no binding, reduce the acceleration by 10-15% and see if it helps.

[IpsoFacto]

Gerry you're a life saver! It was the X that had shifted. Checked for binding and found none so I reduced acceleration by 10% and I'm back in business!!

[IpsoFacto]

Update: it wasn't the acceleration after all but that helped me diagnose the problem. I'm such a wanker! It was a loose coupling. Easing off the acceleration took some stress off the stepper so it looked like everything was fine. When I put in a bigger end mill the problem came back. All sorted now.

Thank again