Hi from Berlin,  John Tuttle's video "Regulating the Stack to the
Piano Action",  https://www.youtube.com/watch?v=U8bAVPeiokE
  shows
the relatively simple process of adjusting the capstan to eliminate
lost motion between player and piano key mechanisms.  But in my case
(Autopiano) everything is hidden behind the stack.  To do what he is
doing in the video would (as far as I know) require a "window" in the
soundboard.

I recently ran the QRS test roll and noticed that there are a half
dozen notes with too much play (you hear the repetitions striking, but
with insufficient response from the hammers).  So, how do I do this?
Note the keys, pull the stack, take my best guess, replace stack, run
test roll and repeat as necessary?

Many thanks in advance for your advice and tips.

Kevin Pfeiffer
Berlin
pfeiffer@tiros.net.geentroep