CME 5C Collet Chuck, 5" Diameter, Plain (Flat) Back, For Lathe Use

I almost thought I got a lemon but made sure the cams are pointed between 3 and 6 o clock (after adjusting the studs) then incrementally tighten the cams and find the best position (out of 3 possible positions) I got 0.0005” TIR. Haven’t put it to use yet but am very happy so far.

Out the box, the chuck would not mount to my D1-4 headstock as the pins were screwed in too far. I attempted to loosen the pins one turn, but one of them required pliers for the entire thread length to turn it. Once removed and cleaned it could not be easily be reinstalled without excessive force. Upon inspection, it was observed that the tapped hole on the chuck backing plate had badly damaged threads. Luckily I had an M10 1.0 tap to clean up the threads. After retapping, the pin threaded in as expected. After cleaning up the mating surfaces, including some surface rust, and installing in all three pin orientations, the best I can achieve on TIR is about .0008". Not bad, but not up to spec.The scroll mechanism to tighten the collet feels pretty rough - you can feel areas where is sticks moderately. Using it a bit cleaned up some of it, but it seems the machining is pretty rough or the burrs were not cleaned up.Overall OK for the price.

Very nice, holds great.

Better than I could believe with very little run out