key bushings

[David Ilvedson]

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When you leave the caul in for that long do you find you need a tighter fit, i.e thicker bushing cloth or you end up with too much play?
David I.



----- Original message ---------------------------------------->
From: Baldwin Yamaha Piano Centre <baldwin@mta-01.sk.sympatico.ca>
To: <pianotech@ptg.org>
Received: Thu, 05 Sep 2002 18:06:25 -0600
Subject: RE: key bushings

Hi Isaac,
I usually leave the cauls a few hours, but noticed that the sizing is not as stable as I like sometime.

I have also noticed the same thing on field repairs using PVCE glue, some times get a recall for a sluggish key.



But as I use most often heated brass cauls, I guess the drying is faster (in surface anyway)

Bin thar done dat.  Still do it if I'm in a hurry.  Usually on a rebuild, we do every thing that is needed to the keybed, then the action analysis, to determine what parts to order.


I think the big area of movement, is the reaction of the water in the glue, on the key button. Leaving them a couple of days, we have found no sizing is needed on the bushings, only sizing the balance rail hole.  This we size with a polished balance rail pin, chucked in a battery operated drill, one quick pull of the trigger, and the hole is sized to perfection.  We size from the top down.  No guess work as to where the friction is coming from.

Key bed fitting, friction control, and key fitting, is perhaps one of the most neglected jobs in our craft.
Regards Roger





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