New action-parts problem

[John Minor]

      A local top-quality rebuilder has installed new NY parts in a
Steinway D and is having some unusual problems. The owner of the
instrument is a concert pianist with high technical demands.
      Here is what happens: On fast repetition, the hammer gets stuck in
the backcheck before the jack re-sets. We've check:

Key height
Dip
Hammer travel
Center pins
Backcheck height
spring tension
let-off and drop
jack to knuckle
jack in window
Key height

Anyone else have this problem with the new NY problems. Could slight
change in hammer bore + - 3/16 affect this.

John Minor
Piano Technician
University of Illinois
jminor@uiuc.edu