[CAUT] Down Weight Too High With New Hammers

[Paul Milesi, RPT]

Am I to understand that the hole in the half-round is not precisely in the
center from front to back, and that it is in fact slightly to the back,
while the bearing is truly "half-round"?  <light bulb moment>

That does explain why they tell you, in the service manual, "The balance
rail bearing should be positioned with its black line (scribed on the felt)
towards the front rail."  Having read this, but having never replaced a set,
I never understood what difference it would make.  Clearly the black line
must indicate something -- I just didn't know what!  I will take a close
look at the rather worn bearings that are in this piano when I disassemble
the action again.

Ed, when you say that "what was accelerated was the ratio, in theory," do
you mean to say that the ratio was increased?  In other words, it might go
from 1:4.9 up to 1:5 as the key is depressed?

Fascinating.  Thank you so much.  Ever so slowly, I'm putting the pieces
together, getting an education.
--
Paul Milesi, RPT
Staff Piano Technician
Howard University Department of Music
Washington, DC


> From: Ron Nossaman <rnossaman at cox.net>
> Reply-To: <caut at ptg.org>
> Date: Wed, 25 Aug 2010 18:59:23 -0500
> To: <caut at ptg.org>
> Subject: Re: [CAUT] Down Weight Too High With New Hammers
> 
> On 8/25/2010 6:32 PM, Ed Foote wrote:
> 
>> It was my understanding that the underlying principle of the
>> patent was two-fold, to have the leads as close as possible to
>> the fulcrum, and to have the balance rail pin slightly distal
>> to the center of the half-round, effectively causing the
>> fulcrum point to shift proximally as the key rocks. What was
>> accelerated was the ratio, in theory.
>> Regards,
>> 
>> Ed Foote RPT
> 
> 
> Verifiable by looking at them, the ratio through the key
> stroke changes far more on a conventional flat punching than
> it does on the half round.
> 
> Perhaps it's another suspension of disbelief patent.
> 
> Ron N
>