Hi, David. Sorry if I missed someone mentioning this, but ... Could the key sticks themselves be warping, twisting, somehow moving? If the plank(s) from which the set was cut have irregular grain, especially if it twists from vertical toward horizontal within a key, you can get very strange behavior as the humidity cycles. Look closely at the culprit keys and see if there's mischief afoot there. If so, you might be able to splice in straighter wood for part of the key, or inlay a stringer to make it stiffer, or just copy and replace the keys. ~ Mark Schecter On Dec 6, 2011, at 7:04 AM, david at piano.plus.com wrote: > Excellent thoughts, thanks, Wim. > > I have been tuning this piano since 1988 and the phenomenon has existed > the whole time. > > I replaced the capstan screws with thicker ones years ago thinking that > this might solve the problem but it did not. Like you, I find it hard to > think that the screws could turn in the wood; they are tight. > > Thanks for the commenbt about sticker curve against capstan curve. > > Best regards, > > David. > www.davidboyce.co.uk > >> >> David >> >> The first question: The round sticker w/cloth against the round capstan. >> That is the ideal situation. The two round surfaces work very well >> together, without creating any friction. >> >> The other question/concern, about the screw moving. I don't understand how >> a screw could turn in the wood, unless it was loose enough that it could >> be turned by you fingers. There is nothing on the felt that would be able >> to turn it. >> >> You mentioned new carpets and new windows. Have these people been doing >> lot of renovating in the house? New carpets give off a lot of moisture. >> New windows mean there is a lot of moisture coming in the house while they >> are replacing them. Any painting going on near the piano? All of those >> things will create a lot of swings in humidity and temperature. >> >> If there is a lot of renovating going on, perhaps you need to ask the >> customer when all the work will be done. Then, when the house is stable, >> check the hammer line again. >> >> Wim >> >> >> >> >> >> >> >> >> >> >> >> -----Original Message----- >> From: david <david at piano.plus.com> >> To: pianotech <pianotech at ptg.org> >> Sent: Mon, Dec 5, 2011 11:23 am >> Subject: Re: [pianotech] Wandering Capstan Screws >> >> >> Thanks for those further thoughts, folks. >> I made a silly mistake, wasn't thinking (am on a course just now and it's >> uite intensive). The piano action DOES have stickers. >> Thinking then about putting action cloth on the ends of the stickers, and >> eplacing the screws with capstans: >> Might there be a concern about the two curved profiles? Would the >> elatively narrow-radius curve of the now action-cloth-clad sticker ends, >> ear OK, and be stable enough, against the radius of the capstan surface? >> I am still kinda feeling that the blue felt on top of the capstan screws >> an't be swelling THAT much, to cause all that lifting. Could the wood of >> he keystick be of some particularly "soapy" variety, that shoves the >> crew threads around, with cyclical changes in humidity? >> With regard to humidity changes, I have wondered for a while if there is >> ome cyclical change going on in that room even thought it doeosn't feel >> amp. The answer, I think, is yes. The room, a study/spare bedroom is >> ust across a corridor from the kitchen, and very near the back door. It >> s quite possible that there could regularly be brief bursts of >> oisture-laden air, which then gets cleared in some way, but in the >> eantime has condensed inside the piano. >> An additional factor at the moment is recent replacement of the windows, >> hich meant the room was cold and damp for a day or two. >> But its still an intriguing question as to whether the screws move. >> I will be returning soon to tune the piano (my recent visit was just to >> heck out a problem following the window replacement - the half-blow pedal >> od had become dislodged) and I suggested leaving the tuning until the new >> arpet was laid and the piano placed where it's to go in the room. >> I will check out the undersides of the blue felt and see how >> impled/ridged they are. If I don't replace the screws with capstans, >> hen I will mark them and the keystick, and see if there is any movemment. >> It occurs to me also to suggest a Dampp Chaser, so that if there is a >> udden surge of moisture-laden air into the room from the kitchen, it >> an't condense in the piano. >> Best regards, >> David >> ww.davidboyce.co.uk >> >> > > >
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