[CAUT] measuring wippen weight

[Alan McCoy]

Jon, Anne, Barbara

I think she does indeed mean a 0.4 change in the action ratio (not a 0.04
change in key ratio).

Bob Marinelli and I were talking about this the other day and he mentioned
that using a half-punching will result in a .5 change in the action ratio. I
have not verified this independently yet, just reporting what Bob said.

I am currently working on a M&H BB with a 0.57 key ratio. I just put half
punchings on it and will install miracle wips to move the wip heel closer to
the balance rail. I need to get the key ratio down to about 0.52, which will
get my action ratio down from 6.5 to about 5.8. Then I'll be able to weigh
it off at a 38 BW using only a 3-2-1-0 lead pattern (and minimal spring
assist). As it was I was going to need 5-4-3-2-1 leading pattern and a 42
BW. Not acceptable for this situatio. This with a newly made set of keys
(not Pianotek)!

 :-(

Alan


> From: Jon Page <jonpage at comcast.net>
> Reply-To: "College and University Technicians <caut at ptg.org>" <caut at ptg.org>
> Date: Tue, 02 Oct 2007 16:52:03 -0400
> To: <caut at ptg.org>
> Subject: [CAUT]  measuring wippen weight
> 
>> There is a .4 change in action ratio either up or down when the half
>> punching or balance rail veneer is used to help correct a high or low R
> 
> 
> I think you mean .04 change.  I have use b/r shims twice to lower KR
> (moving the fulcrum back) and friction.  It was used because nothing
> else worked satisfactorily.
> -- 
> 
> Regards,
> 
> Jon Page