Stickered vs Capstan

[Dave Nereson]

----- Original Message ----- 
From: "gordon stelter" <lclgcnp@yahoo.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: Friday, February 13, 2004 9:34 PM
Subject: Re: Stickered vs Capstan
> --- Farrell <mfarrel2@tampabay.rr.com> wrote:
> > Anyone care to comment on the pros and cons of an
> > upright action with wippens driven by capstans only
> > and one where there is a flanged sticker between the
> > capstan and the wippen (like many tall old
> > uprights). I can only assume the direct capstan
> > would be a bit higher performance, but maybe there
> > is not all that much difference, or maybe geometry
> > can be better maintained with the sticker on a tall
> > piano.
> >
> > Terry Farrell

    I've never cared for the "dowel capstan" arrangement.  Even though a
sticker [how many in the class know these have also been called 'extensions'
or 'abstracts'?] involves another flange and 3 center pins, I think the arc
of the capstan against the bottom of a sticker is a bit less than that of a
dowel capstan against the wippen cushion, thus less friction.  That long
wire and dowel sticking up "amplifies" the arc of the capstan travel.  Plus
the top of the dowel capstan is bigger and wood, rather than smaller and
brass --more friction.
    But that's not the only thing.  When keys warp or twist and their
bushings wear, then those changes are also magnified at the tip of the
dowel.  They never seem to stay aligned to their wippens.  And those fat
wires are hard to bend, hard on the wrist, and hard to tell if they're all
aligned fore-and-aft.  Then after aligning them, when you turn the capstans
to regulate lost motion, you find out they're still not really aligned, and
you gotta do more bending and wrist-wracking.  Long-handled grand backcheck
bending pliers do help!
    Then there's the matter of the darn things splitting when they haven't
been turned since 1917, or even 1977.
    And when you have to remove keys to vacuum or work on the key frame,
keytops, or key bushings, they all wanna fall over or they're in the way.
    I think they're a pain and it seems the better action manufacturers
avoided them (my impression, anyway).  I was surprised when Yamaha started
using them in uprights (both U1 and U3, I believe;  maybe also Kawai and
others).  At least they're nylon and more accurately drilled.   --David
Nereson, RPT