Thanks for your response Don, I am getting poor key return because the action set-up depends on the hammer return springs to do the job. I am adding lead to the back of the keys to achieve key return that is independent of these springs, then weakening the springs to achieve my target downweight. The hammers are pinned so tight before I work on them that a standard swing test will sometimes yield a single swing (no return). I haven't checked how many grams resistance I have when I'm finished, but I'm considering 5 swings (each change of direction counting as a new swing) as reasonably snug. I am normalizing the friction for the jack and wippen flanges as well, and am lubricating every friction point I can identify. I am liking the final result, but the question you answered in your first paragraph has been the puzzle for me. Floyd Gadd Don Mannino said: It's hard to be sure, but most likely the wool fibers have been packed into an unstable position by the swelling / shrinking process, and when you work the parts the fibers are moving a little out of their packed-down positions, thereby adding pressure on the pin. I would suggest that easing the hammer center friction may not be the best answer to better performance in this case. I am not familiar with the particular action you mentioned, so forgive me if it is an especially non-standard design, but most vertical actions perform better with the hammers a little on the snug side. If you are not getting good key return, the hammers should not be the part that does it for you. Look to the spoon / damper lever felt for excess friction, and of course wippen flange and capstan. If the notes return better with the damper pedal down, it is likely the damper lever felts and spoons. If the key return is worse with the pedal down, it is likely the wippen flanges or capstan friction / worn cushions slowing things down. Or of course simply insufficient weight at the back of the key as you alluded to. Don Mannino -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100604/bddb933e/attachment.htm>
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