[pianotech] Jack and Damper Spring Tension Targets

[Barbara Richmond]

I believe that we're talking about upright actions here... 

Barbara Richmond, RPT 
near Peoria, Illinois 

----- Original Message ----- 
From: "Gene Nelson" <nelsong at intune88.com> 
To: pianotech at ptg.org 
Sent: Thursday, July 30, 2009 10:29:08 AM GMT -06:00 US/Canada Central 
Subject: Re: [pianotech] Jack and Damper Spring Tension Targets 


I was shown one method but it is mainly for new, replacement back actions or if you have it out on the bench. 
As I only install springs to the top wound bichord this is what I do. 
Hold the damper tray upside down. Spring tension should hold the lowest lever for note A-0 fast against the tray felt and the top bichord should be suspended about 30mm+/- from it. All the others should be adjusted so that they taper evenly between the two in a nice straight line. 
Works fine for me and when measured with the expensive gram gauge it turns out to be close enough to the Renner spec. 
Gene 


----- Original Message ----- 
From: Gregor _ 
To: pianotech at ptg.org 
Sent: Thursday, July 30, 2009 2:33 AM 
Subject: Re: [pianotech] Jack and Damper Spring Tension Targets 

The damper spring tension should decrease from bass to treble. Sometimes I see in old pianos a pencil line on the damper levers which goes diagonal over all the levers of one area (bass, tenor, treble). I was told that this line was used to measure the spring tension, but I was not told how exactly that procedure works. Does anybody know? 

Gregor 

------------------------------------------ 
piano technician - tuner - dealer 
Münster, Germany 
www.weldert.de 




> From: fg at floydgadd.com 
> To: pianotech at ptg.org 
> Date: Wed, 29 Jul 2009 06:03:25 -0500 
> Subject: Re: [pianotech] Jack and Damper Spring Tension Targets 
> 
> Hi Gregor, 
> 
> Ted's CAUT post of Oct 15/07 is quoted below. He was responding to a post 
> from David Ilvedson, as noted. 
> 
> What I'm exploring here is new ground for me, and I'm trying to establish 
> points of reference. 
> 
> Thanks for your interest! 
> 
> Floyd Gadd 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090730/1ef5c04d/attachment.htm>