[pianotech] Key Leading Documentation

[Paul Milesi]

I ultimately want to learn to weigh off actions and lead keys to achieve
desired down weights, etc., factoring in action ratios, hammer weights, etc.
Just beginning to dig in on this, and thought I'd investigate what various
leading looks like over the years.  I have no plans of "copying" leading
patterns per se.  I'm just finding it interesting now, as I have, for
example, about 10 Baldwin Ls and Rs here at school to compare, as well as a
half dozen Steinways of various models and periods, many others of course.
This summer, it's fairly easy for me to photograph as I have more time and
am breaking down several pianos for various kinds of work anyway.

I'd like to be able to collect data over time that will be somewhat
meaningful or informative when compared.  For example, I find it interesting
that a 4-3-2-1 leading pattern occurs at the breaks.  Why is this?  Hammer
weights are more smoothly graduated, aren't they?  When there is a
transition from a certain number of leads to, say, one less, are the leads
distributed in such a way as to create a smooth curve in key weight (I
forget at the moment what Stanwood calls this) over that break?

Those are the kinds of questions I'm asking right now.

From:  Terry Farrell <mfarrel2 at tampabay.rr.com>
Reply-To:  PTG Pianotech List <pianotech at ptg.org>
Date:  Wednesday, May 23, 2012 10:02 PM
To:  PTG Pianotech List <pianotech at ptg.org>
Subject:  Re: [pianotech] Key Leading Documentation

Are you trying to learn how to weigh off keys in a particular piano, or are
you doing some sort of historical manufacturer key leading protocol?

What is your interest in pattern leading?

Terry Farrell

On May 23, 2012, at 7:17 PM, Paul Milesi wrote:

> 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 Milesi RPT
> Washington DC
> (202) 246-3136 Cell/Text
> paul at pmpiano.com
> http://www.pmpiano.com <http://www.pmpiano.com/>



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