So I have everything working, mostly. I set up a file with estlcam, linear pocketing, 8mm/s and 4mm deep. Plunge is 5mm/s, stepover on this one was 80. It appears that there was enough slack in the belt to allow it to pull the tool in when it was cutting a certain way. In the future I will probably need to use about 45% stepover to work around that. The problem with this cut though, is it seems like it list about 1 mm of z each time it started a new cutting routine. I.e. it would create the first pocket at 4mm of depth, the next pocket would be somewhat deeper, the next series of cuts would be deeper still, etc etc. Until the cleanup cuts at the end seemed to be about twice the depth as I had started out at. When the machine returned home at the end of the cut, the readout had the z as 5 mm, and it was about 1mm below z0 that I had set in the beginning.
It actually lost so much that it hit the piece during travel.
I wouldn’t think this would be an estlcam issue, since the readout seemed to think it was 5mm above zero at the finish.
For the record, I checked the z axis couplers for tightness…