Yamaha Jumping Jacks

[Joe And Penny Goss]

Humm,
Just like regulating the butterfly spring.
Another thing to put in the back of my mind.
?? with the blade of a flat screw driver press down on the two lowest coils
to weaken, to strengthen pry up gently on the lowest coil ??
Joe Goss RPT
Mother Goose Tools
imatunr@srvinet.com
www.mothergoosetools.com
----- Original Message ----- 
From: "Ric Brekne" <ricbrek@broadpark.no>
To: "pianotech" <pianotech@ptg.org>
Sent: Thursday, November 10, 2005 2:24 PM
Subject: Yamaha Jumping Jacks


> Hi folks.
>
> Just ran into a Yamaha C108 yesterday with several jumpy hamers.  All
> were typical bobblers off a jack top at light play.  Most of them were
> solved by simply taking a screw driver and inserting it into the upper
> winds of the jack spring, compressing it fully for a few seconds.  Two
> whippens were pulled after I found jacks too slowly returning after the
> "treatment".  Centers were a bit tight so I changed them, and all is well.
>
> Got to thinking a bit about this tho, and wondered about shimming the
> bottom of the whippen flange as an alternative approach. That would
> lessen the angle of the jack to hammer butt and I would think make it
> easier for the butt to push the jack top away.  Shouldnt be a problem as
> long as there is still enough of an angle for the jack to push the butt
> forward with enough strength.  Would like to hear anyones thoughts on
> the matter.
>
> Cheers
> RicB
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