[pianotech] shift shim

[David Skolnik]

To micro-refine one of Ed's points: the potential problem in his 
preference for the more downward rotation of the short arm is the 
potential for the top edge of the lever (if too sharp) to dig into 
the wood of the frame, causing, within a relatively short time, some 
nasty squeaks'n'creaks.  Breaking that edge could help.  Otherwise, 
what he said.
David Skolnik RPT
Hastings on Hudson, NY


At 07:40 AM 11/14/2011, you wrote:
>         I don't see how shimming anything in the action cavity is 
> going to reduce the free play between the pedal rod and the 
> keyframe( unless you mean shimming the keyframe.  You have 
> two   pivots here, and leather between all.  Where to take up the 
> slack?  I think it best if you have the shift lever parallel to the 
> bottom of the keybed, so that upon rotation, the short arm will 
> push the keyframe as much sideways as possible, with any rotational 
> effect working to push down on the keyframe rather than up.  You 
> may need to bolster the contact point on the keyframe, or add 
> leather at the top of the pedal rod, or check to see that all the 
> pedals are in the same plane, since you may have used thinner pedal 
> cushions, which will introduce a lot of slack.
>Regards,
>
>Ed Foote RPT
>http://www.piano-tuners.org/edfoote/index.html
>
>
>I've rebuilt the piano, The old leather on the trap system has been 
>removed and replaced with new leather. The cavity where the shift 
>pedal activates the action is all there, and doesn't look worn out. 
>The action shifts correctly. It's just that when you press the shift 
>pedal, there is about 1/2" of lost motion. I can, and have, added 
>another layer of leather, which reduced the gap, and the shift does 
>move over a little sooner. (It stops at the action shift screw.
>
>My question was if anyone has ever shimmed the action cavity to take 
>care of the gap, or is adding leather the best solution?
>
>Wim
>
>

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