Yammies, esp. U-1, are infamous for this. Lost motion is necessary for them, more if it is dry. Andrew Anderson On Oct 24, 2010, at 3:02 AM, David Lawson wrote: > I regularly service about twenty pianos at a Conservatorium, both > uprights and grands. The uprights are mostly Yamaha U1 models about > 15 to twenty years old, with a couple of Kawai KS models also. I > regulate the lost motion on these instruments so that the capstan > holds the wippen so there is no lost motion, however, it is not > holding the hammer off the rest. I have just finished the regular > maintenance of these this week, and discovered that all but one had > increased the height of the capstans to hold the hammers off the > hammerest by about 1/4 inch or 6cm. My first reaction was that > someone had been at them, turning up the capstan. However, this is > not possible as I am the only tech. who attends to these pianos. > So, my question is this: Would the sudden change from drought,(about > ten years) to very wet conditions, have brought on this amazing > change? I find it difficult to believe that this much change could > be brought about by humidity. Let's face it, the metal pin holding > the capstan is tight into the rear of the key, which would surely > not increase the height by this much with humidity! I checked the > back touch on the key-frame, and it seems quite normal.The only > piano that did not have this happen to it, had an additional heater > in that room, which may give us a clue. > Your thoughts please. > David Lawson Wangaratta Australia -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20101024/30d05a91/attachment.htm>
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