Schwander action where jacks don't return

Keith McGavern kam544@gbronline.com
Wed, 8 Sep 2004 09:30:18 -0500


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At 7:30 AM -0400 9/8/04, Cy Shuster wrote:
>... About half a dozen keys wouldn't play, because the jack wouldn't 
>return under the butt.  Regulation was OK.

Cy,

Without going into semantics, if regulation were okay, those half 
dozed keys would play.

>  Stretching the jack return springs fixed the problem on some notes, 
>but not all.  From what I could see, there was a center pin in the 
>jack, but no bushing (none that showed, anyway).

Unless it has fallen out or wasn't put in there in the beginning, I 
assure you, there is a bushing in the jack assembly whether you see 
it or not.

>  Is the right fix a new spring, repinning, or lubing the action center?

The right fix is for you to determine the actual cause.

A person does this by examining the worst offending jack assembly and 
checking the pinning for freedom of movement. If there is none, 
correction is required. This act is part of the regulation process.

If there is freedom, then something else is contributing to this 
problem. Maybe lost motion, maybe excess friction in the key 
bushings/balance rail holes, maybe both, maybe something else.

You gotta investigate, man. Discover the cause, decide the cure.

Keith
-- 
Keith McGavern
Registered Piano Technician
Oklahoma Chapter 731
Piano Technicians Guild
USA

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