I'm not getting why you would make a 2 piece chuck body with a adjust-tru feature. If it's one piece when it's mounted to your spindle and then the inside is machined to the collet taper it would seem that is the best it can get. There will be variables as the spindle is not adjusted properly or has some other deviation. The collets themselves will add a slight bit of run out but you can adjust for every collet you use. So a one piece body with careful machining and perhaps grinding seem to be the best you can get. Am I missing something??
