I got a lathe with a D1-4 mount on the headstock. Is there a spec. for how close the back of the chuck comes to the spindle shoulder on the D mount. The face plate and the 4-jaw chuck, that came with the lathe, fit flat against the shoulder, with no gap. The test indicator against front of the face plate only wiggles with the roughness of the surface, so is perpedicular to the spindle axis within < .0005". The 4-jaw chuck had a bent camlock stud, so I'm waiting for a new one before I get into it. The problem comes with the China 3-jaw that came with it ,and a new Bison 3-jaw. When tightened down, the China chuck can have a gap of0.000 to 0.006" between the back and the spindle shoulder. The Bison can have a 0.000 to 0.008" gap. Depending on how I tighten down the camlocks, the runout can be awful. 0.035" on 1/2" ground rod stock 1/4" out from the jaw on the Bison, and much worse for the China chuck. If I'm very carful, and tighten the 3 camlocks sequentially in tiny increments, I can get the China 3-jaw down to ~0.003" runout, and the Bison down to ~0.0005". I thought the D mounts were supposed to be the best for alignment and easy mounting.
Or am I missing something?????