Z Axis Drifting

[jroetz]

I seem to be losing my Z depth, it starts out at the right depth, then as the cut continues the depth gets less and less. I check my zero after the cut and I'm still zero'd out on the machine bed, any ideas on what the problem is?

Picture and file attached, TIA! 


6795-wedges.crv (96 KB)

[gerry]

I'm not sure of the material you're cutting, but you are cutting the full bit width per pass (0.25) @ 100 ipm. That could possible be the problem, but not likely. Your bit could be slipping in the collet. Do you snap the collet fully into the nut before adding the bit? The collet should snap into place with the face of the collet being flush with the collet nut. The collet should not be able to fall out of the nut if it's correct. Your Z axis could be loose, and you're losing steps.

[jroetz]

Material is PVC, it cuts like butter. How do I check for a loose Z axis?

[gerry]

Take the cover off the Z axis. There is a union there that connects the stepper to the spindle. Mark the position above and below the union. Are you chucking the collet correctly?


Collet installation

[Kristy]

If the zero remains the same as it is originally set, then the machine does not appear to have lost position, then the file may be the culprit.

The z-axis becoming loose is not suspected as the machine has not lost its z-zero point. However, changes in the spoil board surface may result in the material not sitting perfectly perpendicular to the z. We would recommend resurfacing your spoil boards.

If you need assistance or have questions, give us a call at [phone].

[jroetz]

Thanks everyone, it must have been the file!