Z depth changes during cut

I am doing a pretty basic dog catch all cut but keep having an issue when I get to the portion of the cut that uses a 60 degree V 1/4" shank to cut the dog’s face from the bowl. I set the Z, everything starts to cut perfect, but about half way into the cut the Z axis gradually gets higher and higher until the bit eventually is doing air cuts. The bit is snug and doesn’t move in the colet and my wasteboard is level. Any ideas what the heck is happening?

Hi Luke,

When you change bits to the 60 how and where do you set the Z height. Are you probing the surface that is being cut or are you probing the top of the material?

After the issue happens if you lower your z to 0 in about the same spot that you probed for z0 is it touching the surface?

To me it sounds like the bit is changing position in the collet. You could try measuring the distance the bit sticks out from the collet before you start the cut and then after to make sure it is not that.


Check your spindle is tightened in the clamp of the bit is not moving. Unlikely you are loosing steps so something is slippng.

I did the latest update and haven’t had issues since… fingers crossed. I think I was losing steps. I’ll keep you posted! Thanks