Radial Digitizing only one Z depth?

[frijoli]

Error always in the same section of the ring, hence thinking kinematics of the probe plus backlash in the screws.

Rotate the probe 90 degrees. If the error moves, it's in the probe. If it doesn't it's backlash

[adatesman]

Error always in the same section of the ring, hence thinking kinematics of the probe plus backlash in the screws.

Rotate the probe 90 degrees. If the error moves, it's in the probe. If it doesn't it's backlash

Excellent suggestion. Thanks!

[adatesman]

Back at it. First, checked TIR on the probe. Is actually at 0.0005" TIR (+/-0.00025). Not going to mess with it at the moment, as fiddly and error I'm seeing is much larger.

First, ran the machine around to get the ways lubricated. Next, mounted the ring gage and bore probe to find center, which I set to 0,0,0. Another bore probe to confirm, then 3 attempts each with the LED front, left, back, right.

Error front/back and left/right match closely, but not off from each other. So clearly a kinematic thing going on. But much less than the wall following error I was seeing, so backlash also likely contributing. Will keep poking.

Oh, I spent a goodly amount of time with a 0.0001" Mit indicator and gage blocks a couple weeks back while bringing the probe online, and trust my screws to be good. Backlash was in the 0.002" range last I checked, but will verify in a bit.