jack hitting h.flange

[Gary Mushlin]

Jon,

The problem is that the wippen and jack continue to rise after the key is
depressed. 
It is the same principal as with the damper system. The back of the key
determines where the damper will end up height-wise, but it is necessary to
have a damper stop rail to keep the dampers from rising any higher than
necessary. The jack and wippen do the same thing to some extent, and need
something to stop the upward motion. Unless the wippen cushion is physically
attached to the capstan, the capstan certainly does not stop the wippen from
going higher until it returns to the capstan. Proof that this happens is
that if you stop the jack with the felt, the clicking stops, because the
jack cannot get high enough to hit the back of the flange. I must point out
that in order for the jack to get that high, the wippen had to rise well
above where the capstan ended up after the key was pushed and held down.
As I stated previously, there was plenty of space on this piano between the
final resting place of the jack and the front of the repetition window, even
with the thicker felt. So there is no danger of the jack blocking and
possibly breaking.

Jon, I think this is something that you have to see in order to believe.
When I first saw it, I still had trouble believing a jack could rise high
enough to hit the hammer flange. Once I believed it, then I knew...this is a
Steinway!

Sincerely,
Gary Mushlin, RPT
> 
> At 03:51 PM 8/20/2002 -0500, you wrote:
>> Jon,
>> 
>> On the piano I examined, the problem was not that the wippen was lifting too
>> high due to capstan placement. I substituted my finger for the capstan and
>> found I could lift some of the jacks higher on some notes than on others.
>> Those were the ones that clicked. With my particular piano, the artist
>> wanted extra aftertouch. We could achieve it with all notes without the jack
>> blocking against the front of the window, even with the thicker felt we
>> (this was a collaborative effort with Rolf at Interlochen on one of his
>> teacher's pianos) installed. The only problem was the few "athletic" jacks
>> that seemed to want to jump higher and faster than the others. Gluing on the
>> felts did not require re-regulating the piano or eliminating the aftertouch
>> that the artist wanted. And the artist was happy with it.
>> 
>> I do think, however, that the problem is inconsistent parts. This was the
>> quickest and best solution we could come up with.
>> 
>> Sincerely,
>> Gary Mushlin, RPT
> 
> The trouble with gluing on extra felt is that if it might stop the jack's
> travel before the end of the keystroke.
> In this case the glue joint between the fly and the tender will be stressed
> and failure is imminent.
> 
> I know of a B whose jacks 'bottom-out' when the keys are 1/16" above the
> front rail punchings. Long hammer blow
> and shallower dip treated the symptoms. Moving the capstan forwards and
> relocating the heel will correct the geometry.
> 
> Jon page
>