> From: "Gene Nelson" <nelsong at intune88.com> > Date: February 28, 2010 10:27:46 PM EST > > Having a difficult time reducing hammer return noise > on a piano with new Tokiwa whips & shanks, new hammers, key capstans, back checks, key pins and bushings, front and balance rail punchings, key buttons, and key end felt. > Key frame is properly bedded. > Action is regulated. > All action frame joints and screws are solid and tight. > All action parts screws are tight. > All centers are at optimal friction with no wobble. > All hammer glue joints are solid. > All whippen glue joints are solid. > Hammer rest rail has new felt, is adjusted at correct height and nuts are tight. > Key stop rail has new felt and is adjusted for minimal up key movement. > I have checked the knuckles - the core is firm dense felt and a needle easily goes in from the side. Buckskin is not too tight over cores. > I have had minimal to zero results using my sugar coater on the knuckle buck skin. > I can depress the key about 2mm, release it and give a slightly woody clunk upon return. > Noise is a bit louder when hammer falls after releasing from check. > Happens on the bench and when secured in the action cavity. > It is noticeable when playing especially in the upper treble section with lid closed but the noise exists in the lower parts as well but not quite so noticeable when playing. Hi Gene, As I'm sure you know very well, action noises are often cumulative (many small noises that add up). Here are a few things that you can try, each of which might help a little bit: • With the stack upside down, mix Protek CLP and teflon powder together, and brush onto the wippen cushions. Then, needle the cushions a lot. • Needle the jack position stop felt (button). • Needle the letoff button. • Needle the drop pad. All three of these can also get a hit of CLP/teflon if it seems to help. • File or sand a *very tiny* rounding or chamfer on the back of the jack top (the side of the jack closest to the hammer head), and coat with Permalon or similar. This slightly cuts down jack return noise, and concomitantly helps the jack to return and reduces the jack top corner's tendency to dig into the knuckle. I would try the above steps on a few sample notes to see if they help. --- Here are a few other things to check, which you have probably already done, but I'll mention them just in case: • How are the balance rail holes? If they are just a tiny bit looser than optimal, they can really add to key noise. • How tight are the new keypins in the action frame rails? • I know that you installed new key bushings, but how is the bushing to keypin fit? I am asking because I have at least once installed new bushings and gotten an ever so slightly loose fit, which increased key noise. • How soft yet firm is the new key end felt? Some of the newer stuff is not as nice as 100 year old felt.... • Other folks have suggested the backrail cloth as a possible culprit. It certainly could be, and I would suggest experimenting with a double backrail cloth if possible. Two layers, each glued down only toward the front of the keyframe and floating free at the rear can be quieter than one layer. Alternatively, one piece in the center covered by a much thinner cloth that is only glued down in front of and behind the main cloth can also be effective (the "snug as a bug in a rug" backrail cloth method). • I know that you said that the new Tokiwa centers are at optimal friction, but they sure do pin them loosely these days! I'm still a bit of a skeptic on that one, and it wouldn't hurt to repin a hammer flange on a particularly noisy note, just to see what happens. I posed some of these as questions, but there is no need to answer them here; I just wanted to give you things to think about (which you may already have done). When you get it straightened out, please tell us how things work out for the action. Joe DeFazio Crosbytown -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100301/419d0aba/attachment.htm>
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