Mark Potter asked: " List - I am having a puzzling problem with a M & H BB grand action that I have never encountered. Complete regulation (w/new shanks& hammers), everything works great with the exception of 3 notes - F6, A#6, G7 - in the high treble. I cannot get this to happen on the bench, and even in the piano when the notes are played softly, even in a trill, they perform perfectly. However, under continuous mf - ff blows, as in tuning, after anywhere from 1 to 10 strikes (letting the key all the way up), the hammer will get caught on it's way back up by the back check, thereby not allowing it to strike. I have tried numerous adjustments to the angle of the back check as well as to the height of check for these 3 notes, to no avail. Everything seems to be identical to the surrounding notes, including jack reg - both in the window and to the knuckle core -, rep spring strength, key dip, stroke, the arc of the tails, let-off, drop, etc., etc... you name it. Keys are rebushed and moving freely. If anyone can shed some light on this puzzler I would be most grateful!!" Mark, My first guess would be that the Jacks are hanging up. Joseph Garrett, R.P.T. Captain, Tool Police Squares R I -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20060925/fe081b3d/attachment.html
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