Looking for some knurling experts advice.
-Dorian Cut Knurl in CNC lathe with 20TP wheels
-Knurling 3/4ish OD aluminum with .05" wall thickness approx 7" long
-Part is supported by live center
Knurl is coming out great but I am getting a twisted knurl. I've attached photo.
Things I've tried: using the Dorian calculator to get a preferred pre knurl OD and knurl depth
Set knurl on center to the best of my ability (both wheels make even contact)
Knurl twists in one direction consistently no matter what I do. If i reverse the rotation of the spindle, the knurl twists in the other direction. Extremely consistent twist, changing pre knurl OD changes nothing.
Thinking maybe some other issue.
I have not tried knurling a solid bar yet. Maybe the thin wall thickness is causing the part to flex/move around while knurling?