I have a Handwheel Collet Closer that came with my Sheldon Lathe. I have been having problems with runout on a 3 jaw chuck so I figured that I would use a 5C collet and the Handwheel Collet closer to check the spindle runout. I chucked up a piece of 1/2" drill rod in the appropriate size 5C collet and checked for run out. It was in the area of .0005. Anyway, I noticed that if I thread the collar onto the spindle all of the way the tapered nosepiece that fits inside of the collar that the collet goes into does not touch the shoulder of the collar. There is a gap of aroud 1/8" maybe a little bigger between the shoulder of the collar and the back shoulder of the nosepiece. I understand that by unthreading the collar a little I can close this space up.
So is the proper procedure to: Thread the collar onto the spindle, then put the nosepiece into the spindle firmly, move the collar up to the nosepiece and leave maybe a .001 gap or smaller, insert the handwheel and the collet and tighten the whole thing up and make sure that the nosepiece seats against the shoulder of the collar.
I was under the impression that the collar had to thread onto the spindle all the way up to the shoulder of the spindle like a regular chuck. I guess this was incorrect or isn't it? Any help greatly appreciated. Thanks, Steve