Somehow my reply seems to have got lost. So here it is again. I think it is a contaminated pinblock. Young Chang had a problem, when at the factory someone wanted the plate screws to go in easy, so they used silicone. This migrated and caused some pins to 'snap' and when they snapped the pitch would drop drastically. If it were the rust, or corrosion, it shouldn't happen when he repeats the process. Jerky pins are also caused by improper drilling, i.e. drill too hot and the hole becomes glazed. Oh yes Matthew, a title in the subject line assists in following the thread. John Ross Windsor, Nova Scotia On 2010-09-05, at 2:04 PM, Matthew Todd wrote: > I also forgot to mention that after I the initial "snap" and me bringing the note back up to pitch, I lowered the pitch a second time on some of the same notes, and it did exactly the same thing (snap, pitch drop) > > Matthew > > On Sun Sep 5th, 2010 11:29 AM EDT Al Guecia/AlliedPianoCraft wrote: > >> Sounds to me like the string rusted and stuck to the agraffe. Once it broke loose it just dropped. >> >> Al - >> High Point, NC >> >> -------------------------------------------------- >> From: <toddpianoworks at att.net> >> Sent: Sunday, September 05, 2010 11:12 AM >> To: <pianotech at ptg.org> >> Subject: [pianotech] (no subject) >> >>> I went to tune a Knabe grand yesterday. On this piano, I decided to drop pitch a little before bringing up to pitch. When I lowered tension on the monochords, I heard a loud snap followed by the pitch dropping drastically. >>> >>> I have encountered an upright that did this and I was curious as to the reason why. >>> >>> Thanks! >>> Matthew >>> Sent from my Verizon Wireless BlackBerry >>> >>> > >
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