more Steinway questions

[Charles Ball]

>1. On some of the new Steinway's I see, but not all, there is a thin piece of
>bushing type cloth under the backrail cloth. Is the purpose of this an air
>damper for noise reduction or is it a quick way to raise or lower the key
>height gang style? I suspect sometimes it is the later because I see it on
>some, but not all of the new grands I see.
>
>2. When using the una-corda pedal I sometimes get a metal to metal click
>coming from the excess play in between the brass locator plate on the bass
>cheek block and the guide pin coming from the keyframe. I have tried adding a
>small shim in the back of the bass end dag to take up some of the play but it
>wasn't very successful. It is an annoying little noise that I haven't been
>able to do much with. Have any of you experienced this problem and if so have
>you had any success dealing with it? On some of these pianos I have been able
>to observe the bass end swim around while using the shift pedal which to me
>seems that the strike point is changing depending on how the pedal is being
>used.
>
>Doug Hershberger,RPT


Dear Doug,

Regarding the first question, I have yet to find a Steinway grand that does
not have the scarlet bushing cloth glued beneath the backrail cloth. I
assume, but do not know for sure, that it plays a cushioning role. Sometimes
beneath that you will find a fiberboard shim in some or all registers. That
is to help  establish correct key height, without having to reduce an
inordinate number of balance rail bearings. I will be prepping a new B
tomorrow, and am curious to see if it has the cloth you refer to.

As for the second question, because of the contact point of the shift lever
on the keyframe, the action does not want to move in a straight line to the
right when the shift pedal is engaged. To prove this to yourself, try
shifting the action without having the cheekblocks in place. Initially, the
pin should have no front to back play in the plate. In time the keyframe pin
routs out the brass plate on the bass cheekblock, causing the noise and
bedding instability you have struggled with. Try removing the brass plate
from the bass cheekblock and hammering it on an anvil to close the slot
somewhat.

If the wear is too extensive, as I often find on older professional
instruments, you will need to order a replacement from Steinway & Sons. The
pin may need replacement as well. You will probably need to file the slot
for a custom fit on the new plate.

Regards,

Charles



Charles Ball
School of Music
University of Texas at Austin