Wim, I second Susan's advice about repinning. If you've got more than 3 or 4 swings now, the problem only will get worse in February, and you can get ready to repin again next year. I've got practice room Baldwins swinging into the teens that bobble in the piano (but not out), even with low tension, that I'm curing with 2-3 swing pinning (two pin sizes larger on average). MUCH better control, AND seems to improve the tone on those beasts as well. Lots of compliments. I also recently solved exactly the same problem you're describing by raising the backcheck level to a horizontal alignment with the hammer tail at drop (as described in the May PTJ). Mine had been doing exactly the same thing -- worked perfectly on the bench (and in the lap) and bobbled in the piano no matter how hard you checked it. It is a 1993 S&S B in a teaching studio with original NY parts. The area most affected was from around C5 on down, perhaps due to changes in geometry from filing, but I don't think I've filed enough felt off those hammers to have made that big a difference (unless someone else beat me to it). This had been a problem with this piano since before the first time I filed them. Backchecks in the treble sections and lowest bass were fine. Before finally raising the backchecks, I'd tried just about everything. This is all given that your new knuckle alignment allows room for the jack to escape. Jeff Susan Kline wrote: > I worked on many of the things listed here, but I think it was firmer >hammer center pinning which made the biggest difference ... that, and >reshaping the tails to 2.5" with a Spurlock-style jig. The firmer pinning >also greatly increased the feeling of controllability. > > Susan Jeff Tanner Piano Technician School of Music 813 Assembly ST University of South Carolina Columbia, SC 29208 (803)-777-4392 jtanner@mozart.sc.edu
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