Also make sure there are no dents raised in the spindle face! Those camlock pins are hard, and you need to be very careful not to bump them carelessly as you put the chuck on the spindle.
The camlocks lock with clockwise rotation. Bring all of them partially to bear, then keep rolling the spindle over and tightening them a bit more. This will help pull the tapers together evenly. The flat face of the back of the faceplate or chuck backplate must close tightly against the face of the spindle when the cams are fully locked. The camlock spindle locates on the taper and face simultaneously to create accurate centering and zero wobble.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)