One thing that you can try with the hammer return springs is to tip the action until the hammer weight overcomes the spring tension. You can then even up the spring tension by seeing where the midpoint of possible rest positions is. And how far between rest positions will give an indication of relative friction. What I mean is a light spring will allow the hammer to be in a lower neutral rest position and more fiction will allow the hammer to stay in a higher position when lifted from the neutral rest position. But you may end up having much more downweight than you planned on. I think it is good that you removed the spring rail, but since you did not subtract that weight from your target downweight, when the spring rail is reinstalled it will be heavier. I am very interested in how you make out. Sounds like a great project. I have a console the seems to have been weighted without the keys having been eased first, and have been wanting to start from scratch. On Wed, Jul 22, 2009 at 11:00 PM, Floyd Gadd<fg at floydgadd.com> wrote: > List, > > I've now completed the rebalancing of the keyboard on my 41" 1965 Heintman, > using targets derived from my measurements on a 42" 1984 Yamaha LU101. > > It was an interesting project, and I'm pleased with the results thus far. > > I used exclusively the 1/2" and 7/16" diameter weights, though I had the > 5/8" weights. The back two inches of the keys were narrow enough in their > vertical dimenson that 7/16" was the largest weight that could be > accomodated there. The only time I had to place a weight that far out was > at the ends of the keyboard--in the bass, because I was using a higher > target of 55 grams, and in the high treble, where my target was 50 grams. > FWIW, I used the target of 46 grams in the middle of the keyboard, as was > recommended to me here by Jeff Deutschle. > > What I found interesting (and somewhat disconcerting) was the lack of > consistency in where I needed to position the weights. I think this would > be due to the influence of the hammer return springs, which must have been > exerting uneven tension across the scale, even though they lined up with > each other when the spring rail was out of the piano and not under tension. > The damper springs, of course, where taken out of the picture during the > weighting process. > > I've a bit more regulating to do before I get a really clear picture of what > I accomplished (or didn't). I still need to regulate the dampers to the > keys, fine tune blow distance/aftertouch, and fine tune the letoff and lost > motion adjustments. > > Here's my question: Do any of you have a method for establishing a > consistent adjustment of the hammer return springs? Bending the springs is > relatively easy. Identifying a measurement methodology and a target value > is new ground for me. I would think, given my experience here, that > attending to the spring issue should come before any messing around with key > weighting. I'm familiar with the procedure for adjusting the repetition > springs on a grand, but I've not seen a procedure outlined for vertical > actions. I done a limited amount of reading in the archives, but have yet > to find anything systematic on this issue. > > Any suggestions, or pointers to old journal articles or specific postings in > the archives? > > Thanks for any help you can give me. > > Floyd Gadd > Manitoba Chapter > > -- Regards, Jeff Deutschle Please address replies to the List. Do not E-mail me privately. Thank You.
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