[pianotech] Damper Lever Resistance

[David Love]

Sorry, talking grands here.  

David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Roger at Integra.com
Sent: Sunday, November 07, 2010 1:03 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Damper Lever Resistance

David,
Your correct to use the least tension vs.effective damping  ratio to set
your baseline. There are many geometrical variances that would make it
difficult to target any given number elsewhere other than the center of the
damper felt. After friction is reduced to a reasonable level, I would start
at 30 - 50 grams (30 in the treble and 50 in the bass) measured at the
center of the damper felt. The 30 - 50 gram baseline would generally define
the needs of most currently produced pianos. A levered gram gauge in easiest
for measuring, but if you don't have one that measures within that range you
can place the action on its back and use gram weights. Another trick to
reduce the spring tension imprint at the key is to keep the rate of damper
travel to a minimum. Using the 50% hammer travel  for damper engagement as
your starting point, bend the tip of the damper spoon backwards to reduce
the travel rate to that which satisfies the lift requirement. Your are, in
effect, changing the ellipse angle of a "cam" that is acting against the
damper lever felt.
Roger Gable


----- Original Message ----- 
From: "David Love" <davidlovepianos at comcast.net>
To: <pianotech at ptg.org>
Sent: Sunday, November 07, 2010 9:59 AM
Subject: [pianotech] Damper Lever Resistance


> Those of you who use gram resistance gauges to set damper lever spring
> tension I'm curious what guidelines you use in terms of the number of 
> grams
> targeted but more importantly, perhaps, where in the damper lever stroke 
> do
> you target: with the damper at rest, at half blow, at the top of the 
> stroke.
> My own goals with respect to this are to achieve effective damping with 
> the
> least possible difference in touch perception between playing with the 
> pedal
> engaged and not engaged.  I don't like to feel that the dampers are 
> playing
> much, if any, role in the touchweight dynamics.  But I've not really been
> able to pin a number on it exactly.   I know when it's right but sometimes
> find myself going back and making corrections.  Renner publishes a 
> guideline
> with their damper tray kits but I tend to find those settings too high
> sometimes depending on where in the stroke you use them.  So, input is
> welcome.
>
> David Love
> www.davidlovepianos.com
>
>
>
>