Key-Capstan-Wippen Heel Alignment

[Dean May]

Hi Terry,

 

It seems to me that you could put that capstan pretty stinking close to the
edge. There isn't going to be a lot of side load and you could reinforce the
thin wall by soaking it with CA or epoxy. It also looks to me like you could
scab on a thin piece of wood on a few of those keys enabling you to move the
capstan a little bit more. Or without a lot of effort for a master woodsmith
such as yourself, just cut 3-4 mm off one edge of the key and glue 3-4 mm on
the side where you need more meat.

 

Dean

Dean May             cell 812.239.3359 

PianoRebuilders.com   812.235.5272 

Terre Haute IN  47802

 

  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Farrell
Sent: Wednesday, May 14, 2008 8:43 PM
To: pianotech at ptg.org
Subject: Key-Capstan-Wippen Heel Alignment

 

Got an old action that I'm rebuilding (all new parts except keys, frame and
rails). The treble keys are not aligned very well with the wippen and hammer
flange holes in the rails. The bass has good alignment, but it gets
progressively worse toward the treble.

 

I made a little alignment evaluation jig, which is pictured below. I have
the left side aligned with #77 hammer flange hole and #77 wippen flange hole
(bisecting the holes). I mark the key with pencil using the jig for
alignment. The dark marks on the back edge of the wippen rail are the little
gaps between the flanges - you can see how poorly the keys align with the
wippen flanges.

 

 

 

 

Below I have pictured one of the capstan location marks where the capstan on
key #77 would align with the center of the wippen heel. You can see how far
off-center it is on the key.

 

 

 

 

A shot with C88 on the left end. C88 key is actually reasonably well aligned
with the wippen/hammer rails, but the others are offset toward the bass -
and not very evenly at that!

 

 

 

So, my question is whether anyone is aware of the best benefit-cost/effort
solution to my alignment problem (short of a new keyset). This action needs
to work very well. I'm thinking the best thing to do is to offset the
capstan some amount (but not so much that the integrity of the capstan hole
in the key is compromised - i.e., not too close to the key edge) and
tolerate the capstan not being perfectly centered with the wippen (making
sure the capstan isn't lifting its adjacent wippen, etc.). Appropriate
compromise should not negatively impact action performance - correct? Or is
there some sort of slick solution out there that I'm not aware of?

 

Thanks.

 

Terry Farrell
Farrell Piano

 

www.farrellpiano.com
terry at farrellpiano.com

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