---------------------- multipart/alternative attachment Mary Bailey wrote: >. . . Another problem with this action is that the knuckles were >creaking and groaning (kinda like my knees after a long week). I >used some teflon on them and that seemed to quiet it down, but I >also asked tech support about that, and they're sending replacement >knuckles as well, since I guess that's another known problem area. > I've never replaced a set of knuckles before, though, and haven't >yet found any articles talking about the procedure - any advice out >there? Mary, The creaking and groaning can be caused as often by galled wooden contact surfaces on the jack and repetition lever as by the knuckle leather. Be sure to smooth the top of the jacks and the repetition lever surface which comes into contact with the knuckles, 600 grit paper will do, followed up with your preferred slip coating. If the knuckle leather appears to be in good condition and not too much out of round, it may be an option to reshape the knuckles, smooth the wooden surfaces and slip coat only - then give the piano a trial period. It may cure the problem without changing the knuckles. When replacing the knuckles, be sure that the knuckle wood is not too long. If the replacement knuckles are 10 mm dia., then the lower part of the knuckle (when fitted) should be no more than 10 mm from the under side of the hammer shank. If this figure is allowed to remain at a larger figure it will upset the action geometry. Furthermore, be sure to insert the knuckles such that they are all in line, ie. make sure that the knuckle center wood is positioned square to the lower edge of the hammer shank. This is important to ensure that the hammer/key leverage ration is constant for all keys. It was this very symptom you describe which lead me to design our new action. Back in 1998, we had fully rebuilt an action just one month earlier when it started to develop these same symptoms. I realised that the unnecessary rubbing between the jack and the knuckle was contributing to the early onset of the disease. The rest is almost history. All the best, Ron O. -- OVERS PIANOS Grand piano manufacturers ________________________ Web: http://www.overspianos.com.au Email: mailto:ron@overspianos.com.au ________________________ ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/e6/af/53/25/attachment.htm ---------------------- multipart/alternative attachment--
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