I had a stability problem with a Yamaha C7 and ended up taking the tension down a bit, applying pressure below the block and tightening the plate/pinblock screws. They turned a 1/4 turn and the piano has be stable since! David I. ----- Original Message ----- From: <JIMRPT@AOL.COM> To: <pianotech@ptg.org> Sent: Thursday, January 11, 2001 2:42 PM Subject: Re: Yamaha C7 Pinblock Fit > Whoa Todd! > > <<"Sure enough - huge gap in">> > the treble section between the plate and pinblock. His question: Would > it be worth his time and their money to try shimming the pinblock?">> > > Are you or your friend sure this is the cause of any tuning instability? > Since we are speaking of a C7 the pinblock is screwed and glued to the rim > and is mortised/glued into the stretcher...are you, or your friend, saying > that a "gap" in the treble section flexes and causes this apparent > instability? If so what evidence is there that this is what is actually > happening? What are the conditions in the church? Is the climate control > system on all the time? are there midweek services in the church? Is there a > DC system on the piano? > > Something obviously is happening to this piano judging by your friends > remarks but.......I seriously doubt it is due even partially to some "gap" in > the treble section of the pin/flange fit. There are Yamahas out there which > have 'no' flange to pinblock contact and are perfectly stable or at least as > stable as any comparable make. > > The supposed "treatment" of the block is an entirely different matter but > again is not needfully the cause of any "instability". Although this > "treatment" of the block would cause me to replace it if the pins were loose > I would not think that the "treatment" in and of itself is cause for > replacement. > > I think that much more information is needed in this case before an educated > evaluation can be made. > > <<"If someone > competent had seen it early on, it could have been fixed by Yamaha at > their expense and saved this church tons of money in tuning fees over > the years.">> > > There seems to be a leap of faith that no one "competent" has ever seen this > piano...do you know that to be the case? In addition there seems to be a leap > of faith that the piano needs to be fixed, should have been fixed by Yamaha. > Again this is not needfully the case and probably isn't. > > Until there is some hard evidence that this "gap" is what is causing the > "instability" problems then I would be very cautious in saying that this is > 'the' problem. If he wants to address the "gap"......... then driving some > wedges up between the flange/block interface will tell very quickly whether > the 'real' problem is at that point. This needn't be a costly or time > consuming procedure for anyone. > My view. > Jim Bryant (FL) >
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