My turret-equipped lathe wasn't repeating well, especially on programs with turret tool changes and I could see the turret rotate a bit when a workpiece was parted off with the 0.160" parting tool insert. It was suggested by S2Jesse and someone else that this might be the result of proximity sensor being out of adjustment and Tormach told me the same thing. I remember what a PITA it was to adjust that sensor when I first got the lathe and that was without the enclosure attached and it looked like adjustment would be a lot more exasperating trying to access the switch adjusting nut through the door in the end panel of the enclosure since one has to locate the sensor with a few tho and then tighten the locking nut without disturbing sensor placement. It occurred to me that a small adjustable parallel might be useful for this adjust so I tried it and it worked out quite well. Attached are pictures of the parallel by itself and in use as a spacer to locate the sensor a set distance from the back turret face. In use, I adjusted the sensor location until the red LED just went out and then used the adjustable parallel as a gage to measure the offset. The parallel was then adjusted to about 0.020" deeper and used to locate the proximity switch while the nut was tightened.
The 1860 file is the parallel alone, the 1857 is a view from the top of the turret showing the parallel in place between the sensor and the plunger nut, and 1859 is a few from the left side of the turret also showing the parallel in place.