Great information. A comment from my Voest manual on pre-setting the
bearings - "Readjustment of the bearing should be done with the
greatest care. It should still be possible to turn the main spindle by
hand rather easily. The best method to check the correct adjustment of
the main spindle is to have it run about 1/4 of an hour at maximum
speed. Afterwards the front as well as the rear main spindle bearing
should just be about handwarm. When the bearings become very hot, the
adjustment should be loosened. However, if no increase of temperature
is observed, the bearing adjustment should be tightened, since a
closely adjusted bearing is an advantage for work with the parting tool
or when fly-turning." BTW, these are Timken tapered rolling bearings.
Good luck.