subjectBobbling hammers and jack spring tension (Mannino)mailed-bygmail.com hide details 12:07 PM (3 minutes ago) Reply Hey Now, I for one would like to thank Don Mannino for his detailed explanation on the correlation of damper spring tension, damper lift/timing, and the effect on bobbling hammers. Don, I have copied this for future reference. You once mentioned at a chapter meeting that changing damper timing (spoon bending), would have a positive effect on bobbling hammers. At the time I had no doubt what you said was true, but I was baffled as to why damper timing would effect the bobbling hammer and the correlation of the two. I have read this several times and I think the light just turned on...or at least it's a little less dim in here. I have a few questions or clarifications. When you say "Damper timing should be at 1/2 of the hammer blow, which should be early enough to make sure that damper lift comes sufficiently before the jack contact." By contact do you mean the jack toe in contact with the let off button? Next clarification, " I place a stack of my old key weights on the damper head at the center point, and find the pressure that balances the spring tension right at the rest point of the dampers. Spring tension increases as they are pressed back, so I find the weight that makes the treble damper start to float at the starting point." Do you mean key Key weights like the ones you determine the down weight at the end of the key? When you say "old" I not sure if you mean old key leads or key weights. As the thread progressed this is one of the questions I had. What is the correct spring tension and how do i achieve it? In the past I have always opted for leaving the let off a little wide approach to the bobbling hammer, it usually works but not always. Hopefully I can master a new approach. Spoon bending is not one of my strong points. Has anyone noticed that this seems to occur frequently on Asian pianos that have the graduated rake for three or four notes right at the break. Some one once told me, I'm not sure who, that it was a geometry thing with the longer hammer shanks. Thanks Don for taking the time to explain this. Steve Blasyak Orange County Chapter Pura Vida -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech_ptg.org/attachments/20090124/1e070ce4/attachment-0001.html>
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