Yamaha jumping jacks

[Paul McCloud]

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Hello, Annie:
    There has been some discussion recently on this list about this phenomenon.  I've also seen it on new Baldwins.  
I don't work on many Yamahas, so I'm not quite sure what is the matter with them.  You could try calling Yamaha service and ask what they recommend.
    On the Baldwins, I've discovered that if you increase letoff, it's less likely to double strike.  The springs are not as strong as the older Baldwins with the spring rail.  The new Baldwins have the same spring arrangement as the Asian pianos (can't recall the name) where the springs have a loop on them.  Because the spring is weaker, you don't need to have the letoff close to get a soft sound.  The hammer has enough inertia to hit the string anyway.
    You can also increase the checking distance a little.  
    I'm sure others will chime in on this.  Good luck!
    Paul McCloud
    San Diego  


----- Original Message ----- 
From: Annie Grieshop 
To: Pianotech
Sent: 11/01/2005 6:01:16 PM 
Subject: Yamaha jumping jacks


Good evening,

I had two tuning jobs yesterday that involved relatively new Yamaha verticals - an M500 and an M450.  Both have very jumpy jacks (or, at least, that's my analysis of why they're tending to double-strike, even when well-regulated), and I'm wondering why.  

Both have plastic jacks and synthetic buckskin.  The M500 had been treated with something that looked graphite-like and was less jumpy than the M450, which leads me to believe that the proper lubricant (or other treatment) might solve the problem.  I would very much appreciate any suggestions as to how to proceed.  Thanks!

Annie Grieshop
in the wilds of balmy Ioway, where winter is still in our future.....
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