Key Height

[Farrell]

Arrrggg! Yes, of course the capstan would rotate backwards as the key goes up, but how much did she raise the key height at the center pin? 

HEY Z! How much DID you raise the keys?

Let's say you put a 0.050" punching under all the keys at the center rail. That would raise the key fronts about maybe 0.120" - a good 1/8". That's a fair bit of a raise. How far would the capstan tops rotate back? Hmmmmm. I calculate............exactly................not much! It just couldn't be more than 0.005". And then don't forget the capstan top actually rotates, so the point of contact on the capstan top moves forward as the capstan body rotates backwards - thus lessening the effect.

But maybe it is enough? One of the classes I will be taking in Chicago is Jack Wyatt's upright action class. From the PTG web site:

(A) "Upright Touch" on the Up & Up
Jack Wyatt, RPT, Dallas, TX Chapter
In upright regulation there are always the fundamentals and then there are the "others". The trick is not to violate the fundamentals and use the "others" to achieve the touch that you want. This can be done in several ways. Your duty is to select the correct combination. This is an exercise in giving a little here and taking a little there. Learn the seven points that make the difference. It is a practical approach to an end result. This class is designed for experienced technicians.

I'll be very interested in watching this thread unfold.

Terry Farrell
  
----- Original Message ----- 
From: "Joe And Penny Goss" <imatunr@srvinet.com>
To: <pianotech@ptg.org>
Sent: Sunday, May 05, 2002 9:42 AM
Subject: Re: Key Height


Zi,
By raising the key height you also moved the capstan back under or in this case to a more favorable position under the wippen cushion. 
Don't just try this on all actions as the geometry might not be the same the next time. <G>
Joe Goss
imatunr@srvinet.com
www.mothergoosetools.com
  ----- Original Message ----- 
  From: Z! Reinhardt 
  To: Pianotech 
  Sent: Sunday, May 05, 2002 6:51 AM
  Subject: Key Height


  How DOES one go about teaching how to establish proper key height in an upright?  I've heard discussions about parameters as determined by case parts, balance pin height, and so on, that doesn't really home in on the optimum key height.

  Recently I came to a fairly new delivery where the customer complained that she couldn't get sufficient repetition.  Two other technicians before me had tinkered with the action enough to get sufficient aftertouch, but the piano played with all of the grace of a heavy truck.  Both technicians had confessed to the customer that they were not pianists, and had done as much as they could according to the manufacturer specs.

  Now I'm hardly a pianist myself, but my first sense was that the keys were sitting too low.  OK, raised the key-height, and regulated the action accordingly, including adjusting the key depth.  Got a nice aftertouch equation and turned the customer loose on playing it.  She reported that the action now flies.

  What have I done?  Both technicians and the dealer all want to know.  I told them what I could, but realized that I had no real way of explaining how to determine what the optimum key height should be for any particular upright piano.  The original key height was well within the parameters mentioned above when I first came to the piano, but I knew it could be greatly improved ......

  Any ideas out there?  Thanks!
  Z! Reinhardt  RPT
  Ann Arbor  MI
  diskladame@provide.net