At 06:43 PM 1/31/97 -0500, you wrote:
>List Members,
>
>I have what I think is a 1930 Steinway B with a telfon action
>that has been installed / serial # 272377. The key frame
>is replaced & .147 balance rail pins , originals would have
>been .160, and the half round "accelerated" dowel.
>Hammer c/p to wippen c/p = 4 1/2 "
>Hammer c/p to hammer center = 5 1/8 "
>Keybed to hammer c/p = 5 3/4 "
>Are these numbers close?
>The action feels like a truck down weight started out at 85 gr.
>with an up weight of about 40 - 41 gr. With some weight removed
>from hammers and shanks and some other friction problems -
>got down weight to 69 gr. there are still a lot of problems.
>Question is can this ever work? I think the best thing would be to
>start over again, but the client just got the instrument (should
>have called a tech first) . The piano really sounds pretty good
>refinished and re-strung w/ new block - soundboard is in very
>good condition. Just wonder if I'm spinning my wheels and
>wasting time and client money on this current action?
>
>Any help or input on this would be greatly appreciated.
>Mark Ritchie RPT
>Cols OH
>
>
Mark,
June issue of Journal, pages 16-18 show David Stanwood's article.
The numbers you have here initially shout hammers heavier than keys.
Balance weight is way off. Friction levels will change after repinning
parts (see below) Leverage needs calculated (under leveraged aids in same
results). On about 6 or 8 sample notes, take the measurements according to
the article. You'll need Note DW UW BW Fric Strike W FKeyWt KeyRatio WipWt
WipBalWt TopBalWt StrikBalWt Strike Ratio. The formulas are given in the
article. A spreadsheet is easily created for a working table like the one
below. The first example is taking your UW & DW (with assumptions of SW,
FKW, WpWT & KR) The SR on this scenario is incredibly high (excessive
friction will do this as well)
DW UW BW Fric SW FKW KR WpW WBW TBW
SBW SR
85 40 62.5 22.5 10.7 33.1 0.496 17 8.432 95.6 87.168 8.15
Other Sample Stuff
51 19 35 16 11.9 46.1 0.53 18 9.54 81.1 71.56 6.01
52 22 37 15 10.9 49 0.52 18 9.36 86 76.64 7.03
47 23 35 12 10.2 28.2 0.51 18 9.18 63.2 54.02 5.30
60 42 51 9 11.4 22.1 0.48 18 8.64 73.1 64.46 5.65
60 40 50 10 11.9 46.1 0.53 18 9.54 96.1 86.56 7.27
60 40 50 10 11.6 24.7 0.49 18 8.82 74.7 65.88 5.68
Repin all teflon parts (on a few samples). Dry teflon powder knuckles,
polish capstans, and be certain that the rep spring isn't binding in
lever---keys/bushings can create alot of friction all by themselves---free
them: do UW & DW again. This should change numbers dramitically. The
existing parts should be replaced anyway. New Renner samples applied (
regulated, rep spring tension, checking, etc.) will greatly improve your
numbers...chances are you will need to move your capstan down a bit (which
is good-improving leverage). Create your straight line from balance rail
pin to whippen flange centerpin (I use a piece of thread). Optimal line-up
would be capstan moving through the line at half keystroke.
Spread is close...4 13/32 might be better. Try with Renner samples
and check spread measurement, you may find a slight difference. Other
numbers ok. What shank is used? (most likely the brown knuckle 15.5
centerpin to knuckle core). If so, remember that this is a low leveraged
shank...houses less hammer weight. Using the new Rennner modified 16.3
(correct me list, it might be 16.5) allows for less hammer weight
reduction=higher leverage. The larger size Steinways do seem to vary from
one piano to the next...B's & up. S,M,L seem more consistent.
Considering that the instrument is a "B", it is well worth replacing
the action components with superior parts. Taking these crucial measurements
will also aid in the determination of other problematic areas. David
Stanwood offers application of his patented weighting system as well as
complete re-design, hence the New touchweight metrology. You may write to
David at the following e-mail address: stanwood@tiac.net
The existing parts, even if one were to spend all the time and
effort replacing teflon/repinning, still would not be nearly as nice or long
lasting as new parts. You'll extirpate many demons choosing new parts and
your customer will play with immeasurable joy (I was going to say jump, but...).
Best wishes
Dave Swartz, RPT
dms2000@pioneerplanet.infi.net
Majestic Piano
Website: http://www.majesticpiano.com
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