Backchecking problem

Avery Todd atodd@UH.EDU
Fri, 12 Jun 1998 10:56:59 -0500 (CDT)


Tom,

   Maybe I overlooked someone mentioning this, but how is the height of the
backcheck in relation to bottom of the hammer tail when at let-off?
Couldn't that affect it?  How about nap orientation on the recovered
backcheck?  Also, how is new knuckle size & placement compared to old?
   It sounds as though the jack is having to be forced on forward out of the
way by a very hard blow. If so, why? I realize also, it could be too heavy
hammers compared to the old, necessitating overly strong spring tension.
How does the hammer weight compare?
   I can empathize with your frustration. Been there. I'm sure you've
probably already thought of all this but thought I'd grasp at a few straws
here, just
in case.
   Let us know the problem when you solve it.

Avery

>I am stumped with the backchecks on this piano. The piano is an early 80s
>S&S L with new Premium blue hammers on Renner shanks & flanges and
>re-leathered original backchecks. I have CLOSELY regulated key height, dip,
>let-off and drop, spring tension, and all the other usual suspects. The
>problem is that the hammers absolutely refuse to check when the note is
>played at the level of forte or less. They just bounce between the
>backcheck and the string. The angle of the backchecks is good and they
>check high enough, but I just can't seem to get them to work in the piano.
>The problem is particularly bad in the bass and tenor, where the hammers
>are larger.
>
>The problem may be in the balancier. When I push the balanciers down, there
>seems to be much more spring resistance than normal although the hammer
>rise is not particularly fast. The original wippens have been rebuilt and
>repinned, so I'm pretty sure that it is a not pinning problem. The slots
>are clean and the springs have been cleaned and polished.
>
>Tom Seay

___________________________
Avery Todd, RPT
Moores School of Music
University of Houston
Houston, TX 77204-4893
713-743-3226
atodd@uh.edu
http://www.music.uh.edu/




This PTG archive page provided courtesy of Moy Piano Service, LLC