....
Any constructive suggestions would be appreciated.


2.9. Why won’t this chuck hold parts exactly on center?
2.9.. No chuck or collet is perfect. Even a new three-jaw chuck is
only good to 0.002” or so unless it is adjustable. If your chuck won’t hold
parts that closely, something is wrong. Here’s a list of possibilities.
Any of these could cause a good lathe to wobble.
It could be that the jaws of the chuck are worn. Letting parts spin in the
jaws wears the chuck quickly.
It could also be that the scroll of the chuck is worn. The scroll is a flat
spiral metal plate behind the jaws.
Another possibility is that the chuck is mounted on the backplate wrong or
that there are dirt or chips between the chuck and the backplate. Take it
apart, clean it carefully, oil it, and reassemble it. That may help.
Still another possibility is that there is dirt or chips between the
backplate and the spindle. Unscrew the backplate from the spindle, clean
the threads in the backplate and on the spindle, oil both, and try
assembling it again. Screw it together gently. It should not be forced
together or spun on fast with a snap.
It could be that the spindle is bent. Put a dial indicator on the spindle
nose to check it.
It could be that the spindle bearings are bad or that the spindle is
improperly installed. Good bearings will feel smooth and have no play.
Logan spindles are precision machined to give the bearings a precise preload
when the spindle is correctly assembled. Preloaded bearings have no play.

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2.10. What can I do to fix a 3-jaw scroll chuck with worn
jaws?
2.10.. If the scroll is worn, there’s nothing you can do without a CNC
machine and a lot of time. If the scroll is worn and you fix the jaws, the
chuck will be true at the diameter that you used for the repair, but nowhere
else.
If you’re sure that the problem is just the jaws, then you can set up a
toolpost grinder or boring bar and regrind or bore the jaws true. However,
you must do this with the jaws pressing against something. One way to do
this is with a piece of sheet metal having holes for each jaw. Another way
to do this is to drill holes in each jaw for a pin or screw, and have these
pins or screws tighten down on a piece of pipe. Tighten the chuck on the
sheet metal or pipe and the jaws will be locked in the right place.
http://lathe.com/tips/chuck-jaw.htm