repetition/backcheck problem

Charles K. Ball ckball@mail.utexas.edu
Thu Aug 20 06:57 MDT 1998


Dear Don,

I would be curious to hear which parts you chose for the action rebuilding.
We have had similar problems to solve here in the past, and usually the
cause was due to the relationships among the various parts.  For instance,
I have found that shanks with a 16.2 or 17mm knuckle set do not work very
well with original Steinway reps.  Also, with these parts, there may be a
need for a change in the spread specification.

On the other hand, we received a new Steinway D last year which had a very
similar repetition problem, and I tried many of the expedients that you
mentioned, some at the suggestion of factory techs.  Yet the problem seemed
to gradually disappear on its own over time as the action settled
in--whether due to or in spite of my efforts I cannot say.

I must say that whenever I have encountered a serious repetition problems
like this, it has typically been resistent to subtle adjustments, such as
changing the backcheck angle, etc.

Regards,

Charles

>> List,
>>
>> I am having a repetition problem with an action from a Steinway L, vintage
>> 1940's. The solution is eluding me and I hope someone can give me some
>> insight or better yet, the cure!
>>
>> I started servicing this instrument several years ago. The action was
>> extremely worn. My customer was saving money to have the parts replaced so
>> I did my best to make the action function until the work could be done. (He
>> is a very good pianist) One of the problems was during a short but fast
>> repetition, on one note, the backcheck would catch the tail of the hammer
>> thus failing the repetition. (Two to four or five strikes and fast enough
>> repetition that the key does not come all the way up.) I thought this
>> problem was due to the extreme wear of the parts that made it impossible to
>> get a good regulation. For a temporary fix, I affixed a strip of action
>> cloth across the top of the wippen rest felts. (The shanks were very high
>> due to hammer wear.) This solved the problem until the replacement could be
>> done.
>>
>> I have now replaced the parts, and you guessed it, the problem is still
>> there. After experimenting with different backcheck angles, taller wippen
>> rest felts, shimming the back feet of the action brackets (1/16" higher)
>> and regulation changes, I have not found the cure. The hammer tails were
>> shaped with jigs I made using the Spurlock method described in the PTG
>> Journal several years back. I did leave the tails a bit longer than the
>> originals. The measurement from shank center to the tail end, on the old
>> hammers, was about an inch. I left the new ones at 1 1/8" but the radius of
>> the tail shaping is the same. Comparing dimensions with a similar Steinway
>> L here at school has shed no clues. As you can tell, I suspect a geometry
>> problem but I cannot find where. Any help with this quandary would be
>> greatly appreciated.
>>
>>
>> Don McKechnie
>> Ithaca College
>> dmckech@ithaca.edu
>>
>>


Charles Ball, RPT
School of Music
University of Texas at Austin
ckball@mail.utexas.edu




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