Backchecking problem

[Don Mannino]

Thomas D. Seay, III wrote:
> 
> Dear list,
> 
> 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.

Tom,

I would look into the following things:

1. Old repetition spring was bent wrong, is pressing up on the rep lever too close to the center pin. If bad, put new springs in.
2. Repetition spring slots are gummy. Clean them out and relubricate.
3. Hammer tails are too smooth / backcheck skin doesn't have good nap. Rough the tails up.
4. New knuckle location or size is not correct.
5. New shank center is in the wrong place (would be minor contributor along with something else).

I missed the earlier replies to your post - sorry if these are repeat points.

Don Mannino RPT