Thanks Bill! Yes, I think you hit on it! I thought the very same thing while looking at it in my shop and observing the jacks and thought that maybe there was not enough LM which could, indeed cause the hanging jack problem. I believe there is INsufficient lost motion! No, the jacks were not hanging up on slow release. I'm reinstalling the action in the morning and will check that there is enough lost motion. Thanks! Terry Peterson Date: Tue, 18 Mar 2008 20:56:27 -0500 From: pianotech at a440piano.net Subject: Re: Yamaha jack question (I figured...) To: pianotech at ptg.org So, if you file it under unexplained mysteries, what does that do for your client? Sheesh, Terry, give us a minute. Probably not too tough to figure out if the action is in front of you, but in cyberspace a bit more challenging. You said it was in proper regulation. How much lost motion was there? On a slow release of the key, does the jack reset properly? Without more diagnostics, my first instinct is that the jacks are hanging on the butts because there is not "enough" lost motion - e.g. clearance for the jack to return. If as you say, everything is sufficiently lubricated, I don't suspect more lubrication will help. Neither do I suspect that the jacks being plastic has anything to do with the problem. You said the jacks were not resetting. Why? What were they hung on? Were they hung on the butts? Would the jacks reset if you push the hammer forward? Push the wippen down? I guess what I'm trying to determine is what you did to get the jacks to reset as you were diagnosing this. Presumably, if the centers were not too tight or the springs too weak (how did you check this?) you could have made the jacks reset somehow by fiddling around in there, moving hammers, keys, etc. More info would help. William R. Monroe ----- Original Message ----- From: pianolover 88 To: PIANOTECH at PTG.ORG Sent: Tuesday, March 18, 2008 7:31 PM Subject: RE: Yamaha jack question (I figured...) I kinda figured this one was a bit too tough to figure out. I guess I'll have to file this one under unexplained mysteries. But thanks anyway. Terry Peterson From: pianolover88 at hotmail.com To: pianotech at ptg.org Subject: Yamaha jack question Date: Tue, 18 Mar 2008 15:42:42 -0700 Customer owns a yamaha console, only about 11 years old with minimal use. Got a call that some keys were sticking. Upon inspection I confirmed quickly that the problem was *not* in the keys, but the jacks. Turns out that many of the jacks (plastic) are having trouble resetting back under the hammer butts for some reason. This happens whether the damper is depressed or not, when repeating the same notes at a reasonable speed, but less than trill. A check of the action determined that the regulation is correct, the centers are not tight, the hammer butt buckskin is not worn at all, and the jack springs are not the problem. I also noted that the top of the jacks have sufficient slickness/graphite. So what could be the source of this problem? The backchecks are also properly regulated. Should I try spraying McLube on the tops of the jack, then brushing on some powdered teflon? Could it be that the jacks being plastic could be part of the problem? Terry Peterson Connect and share in new ways with Windows Live. Get it now! Shed those extra pounds with MSN and The Biggest Loser! Learn more. _________________________________________________________________ Helping your favorite cause is as easy as instant messaging. You IM, we give. http://im.live.com/Messenger/IM/Home/?source=text_hotmail_join -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20080318/f5f2dfbc/attachment.html
This PTG archive page provided courtesy of Moy Piano Service, LLC