On 2010-07-13, Pete C. wrote:
Except for the fact that his encoders have no shaft to couple and no
bearings. His code wheel will automatically be centered on the motor
shaft, he just needs to mount the reader head within tolerance around
the code wheel.

Correct.

The center hole he is drilling is just clearance for the motor shaft
and definitely does not need to be precision bored, it just has to
not rub on the motor shaft.

The reason I want to locate all holes precisely is to align
everything.

Thus the hole for the motor shaft is very close (0.06mm) to the motor
shaft diameter and I want all other holes to be located precisely,
with minimal slop.

The first plate seems to have worked out well.

The mounting holes for the reader head, and the holes to mount the
adapter plate to the motor are the important ones, and all of those are
small holes that don't need to be bored either. With the tapered
centering tool that he'll either buy from US Dig or make, he can readily
center the reader head around the motor shaft and then secure the head
and mounting plate.

I am afraid that if I allow slop in mounting of the reader head, then
if I accidentally knock the encoder, it will become misaligned. The
mount that I already made and used, has no "play" in head mounting, so
an accidental bump would not change any alignment.

i