Steinway M problem

[BobDavis88@aol.com]

> Subj:	Re: Steinway M problem
>  Date:	97-03-22 02:47:45 EST
>  From:	ilvey@a.crl.com (David ilvedson)

>  Steinway's plates are cast in the
>  old fashion way with a sand mold into which molten cast iron is
>  poured.  Because this is not exactly a precise way to make a
>  plate, slight differences are formed from plate to plate.  The
>  bellyman is given a piano with an installed plate and strings
>  and his job is to match the action to whats there.  He fits the
>  stack(with wippens and hammers, shanks and flanges)  to the
>  keyframe aligning to the correct striking point using gauges
>  made of wood.

I think you're referring to the forefinisher, who gets the piano from the
belly department. Not only are there differences in the plate casting, but
also slight differences in way the plate fits at the pinblock, the pinblock
being put in first, and the plate fit to it. Okay, okay, wrestplank. Anyway,
you're right, the action stack is "floated" under the strike point, the
keyframe is fitted where it needs to go with reference to the case, and the
difference is taken up in the capstan line, resulting in small differences in
leverage, piano to piano.

Somebody probably goofed slightly on this piano, but the click might still
not show up at first. I don't remember if this piano still had angled
capstans. I think so, and if so, even small things like knuckle and heel
cushion compression can make a difference if the contact point is really
close to the click point to start with. As they compress, and the capstan is
raised to compensate, its contact point goes back a tiny tiny amount. Also,
until it compresses, the heel cushion could hold the capstan away from
contact with the wood. What I'm saying is that maybe this piano didn't click
for a number of years.

If capstan placement was wrong to begin with, it wouldn't necessarily be
deducible from the regulation. A difference of 2 mm in capstan placement does
make a difference in the dip, but it's only about .015, which is tolerable.
It will only change the downweight about 3 grams.

Bob Davis