Messrs. McClelland, Tuttle and others have provided excellent advice
on how to efficiently and easily regulate the player stack fingers or
capstans to the piano wippens.  I'd like to add something that has
usually worked for me, in situations where the average general level
of the player fingers or capstans is a bit too low or too high for the
piano action, which can happen especially if one has also refurbished
or rebuilt the piano action.

Instead of turning every player capstan several turns up or down,
I first decide how far off the player action is off from the piano
action, then I shim up (or down) the entire top player stack so the
general average heights are correct to the piano action.  At this
point, a few to a dozen or so of the piano hammer shanks will be held
off the hammer rest rail, but a few others will still need their player
capstans brought up.

Shim stock can be anything which is easy to cut and shape and is
firm and won't compress with age, such as thin birch hobby plywood,
business card stock, or the thin, firm pressed cardboard from the back
of a writing tablet.

Some player actions such as Amphion (similar to Ampico A upright
actions) already provided stack height adjustment screws on both bass
and treble.  After making this adjustment, there will usually be far
fewer capstan screws needing turning, making the entire procedure
easier, and the capstans needing adjustment will need only one-half
to one turn.

Fred Scoles
Oswego, New York