[pianotech] key leading documentation

[Joseph Garrett]

Exactly! A most incorrect way to weigh off keys IMO. The mass of the key, the friction factors and the differences of hammer mass were not taken into consideratin!
That's my take on it.
Joe


----- Original Message ----- 
From: Al Guecia/Allied PianoCraft 
To: joegarrett at earthlink.net;pianotech at ptg.org
Sent: 5/24/2012 5:01:19 AM 
Subject: Re: [pianotech] key leading documentation


Joe, I don't know what's going on now, but when I worked at Steinway, every grand action was weighed off. 


The person doing the job (I can't remember his name. Big old Irish fellow) got the action with a lead pattern for that model, then he proceeded to weigh and adjust each key. He would then drill and insert leads as needed. I also noticed that he rarely removed lead. If the key was to heavy or he didn't have a good location or size, he added weight to the front to counterbalance.


Al -
High Point, NC






On May 23, 2012, at 11:13 PM, Joseph Garrett wrote:


Paul said:
"If I were interested in studying key leading patterns in different pianos
by
taking pictures of certain keys, which keys would be the most
useful/representative? I find it easy to lay out all the Cs one below the
other, but this does not show the typical changes in numbers of leads
between sections, or where they occur. The difficulty I have found in
trying to capture the first and last key of each section is that photos of
black keys do not easily show the leads, which have been painted. Also, I'm
not sure comparing #26 sharp leading with #27 natural leading is the
best/most meaningful. Ideas? Does anything like this already exist
someplace?

Trying to learn about action ratios, inertia, etc. -- that is, from the
point of view of what's been done in the past, is common to certain makes,
models, periods of manufacture, etc. Thanks in advance for any suggestions."

Paul,
There are two ways that keys were leaded, imo. 1. a pattern was taken from
the prototype piano and was used on all of that model, regardless of the
considerations of friction, assembly line errors, different key material
masses and any other thing having to do with the actual function of a piano.
2. There have been a few factories that made the action correctly, in
regards to friction and action geometry, w/in the boundaries of mass
production, (albeit small quantities), and weighed off every set of keys
before the darn thing went in the crate.
I don't think any U.S. companies fell into #2.<G>
Studying what they did, really is of no concequence and is, imo, a waste of
your valuable time. Better to take John Rhodes/Darrell Fandrich class on
inertia. They'll answer all of the questions rattling around in your
punkin'.<G>
That's my take on that. 
Joe

Joe Garrett, R.P.T.
Captain of the Tool Police
Squares R I
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20120524/eb0259ad/attachment.htm>