[CAUT] Upright geometry problem (Nordiska)

[Ted Sambell]

Several years ago I attended the Europiano comvemtion in Germany, at which 
engineers from Schimmel dealt with this question. For the jacks, simply use 
a force gauge, placing the feeler on the jack heel and moving the jack 
forward  with it. The recommended reading is 30 grams, not more. To check 
the damper springs, mount the action on the bench horizontally with the 
dampers uppermost and use the force gauge on the damper felt to press 
downwards about the distance of the damper lift. The optimum reading is 40 
grams. The engineers said that increasing the spring strength above this 
does not improve damping efficiency. In my experience I have found that 
excessive spring strength also causes hammer bobbling.

Ted Sambell
----- Original Message ----- 
From: "David Ilvedson" <ilvey at sbcglobal.net>
To: <caut at ptg.org>
Sent: Monday, October 15, 2007 1:18 PM
Subject: Re: [CAUT] Upright geometry problem (Nordiska)


>I know how to reduce or increase the tension it is getting it even that I'm 
>wondering about...some sort of gram gauge pulling on the damper?   Maybe it 
>is simply trying to pull the spring towards you the same amount for each 
>damper?
>
> David Ilvedson, RPT
> Pacifica, CA  94044
>
> ----- Original message ----------------------------------------
> From: "Richard Brekne" <ricb at pianostemmer.no>
> To: caut at ptg.org
> Received: 10/15/2007 10:07:59 AM
> Subject: [CAUT]  Upright geometry problem (Nordiska)
>
>
>
>>Carefully  :)  Seriously... you know how to do this yes ??  Perhaps you
>>meant jack return spring ?  Thats a bit time consuming but it can be
>>done if you are patient.  In the worst case... the things are glued in
>>both slots and then you have to replace them if they are too strong.
>
>>Cheers
>>RicB
>
>
>>    How does one reduce the damper spring tension evenly?
>
>>    David Ilvedson, RPT
>>    Pacifica, CA  94044