Plate Bushings - was Re: Bushing vs. bigger pin?

[Ron Nossaman]

>The bushings are supposed to reverse the load direction placed on the
>pinblock, thus allowing for a lousy fit to the plate flange. The idea is,
>as I understand it, that without the bushings, the pinblock is pulled
>towards the flange by the strings, whereas with bushings installed the pins
>actually try to pull the pinblock away from the flange. The bushings are
>supposed to act as a kind of fulcrum I guess. Indeed a few of these fellows
>state that the real reason for the bushings is to accomplish exactly this,
>exactly for the reason of making the pinblock fit to the plate flange less
>critical.

I like plate bushings for the reasons I listed. They decrease flagpoling,
keep the pin off of the plate, and improve the feel during tuning (in my
opinion). I have no scientific documentation, no charts or graphs, no
formulae, nor automatically accepted and unchallengeable opinion of a
"Steinway Tech".

I haven't seen convincing evidence to the effect that plate flange fit is
critical to tuning stability in the first place, and certainly don't see
any logic in the idea that they will lever the pinblock away from the
flange, keeping in mind that every non-proponent of bushings reasonably
points out that they won't support pressure without smashing. They won't,
however, smash down to nothing. At a certain point, they will have
compressed to the point where they WILL support string tension and keep the
pin away from the plate. There will be more friction between the pin and
the bushing than between the pin and the plate, which will give a better
feel (again, in my opinion) to the pin during tuning.

The next time you tune a piano without plate bushings, look and see how
many of the pins are riding the plate, and consider if that is a somewhat
similar circumstance to the bushing leverage theory. Where's all that
flange gap induced tuning instability that's supposed to result? If it's
such a horrifyingly big deal that so many accept as Gospel and pass on as a
great truth, wouldn't you think there would be some detectable evidence to
that effect? Or is all this just camouflage and a smoke screen to use as an
excuse to not have to spend an hour fitting a block to a plate flange? If
that's the case, they ought to just butter the block with epoxy and get on
with it. I don't see the point in trying to give plate bushings a bad name
because Steinway doesn't use them. Incidentally, a well known Steinway
employee (since gone elsewhere) once told me that putting bushings in a
Steinway would kill the Steinway Sound. He said it disrupts the "Circle of
Sound" between the strings, tuning pins, pinblock, plate, horn, beams, rim,
soundboard, bridges, and back to the strings. He didn't mention the Easter
Bunny, which I don't believe in either.


Ron N