[CAUT] lighter touchweight

[Chris Solliday]

Ric,
 you are right the difference is small when only removing WW but much more
so with assist springs, which I may have mentioned in my previous posts on
the subject. Is it as much as other removers/affecters? no. Does it  (use of
springs) cause an atypical feel from that loss of friction and less break
away resistance (with less lead/key mass)? yes.
As for Nordic you have only to ask.
C
----- Original Message ----- 
From: "Richard Brekne" <ricb at pianostemmer.no>
To: <caut at ptg.org>
Sent: Sunday, October 21, 2007 5:10 PM
Subject: [CAUT] lighter touchweight


> Hi Chris
>
> Grin... dont really see what you are apologizing for, but let go.  Your
> posts have been thought provoking and well thought out seems to me.
> I've heard about the class you refer to and hope to run into this one on
> one of my infrequent visits stateside... HEY !... perhaps we can get you
> two to do the Nordic ?  :)
>
> I still dont really see clearly how we are going to see a significant
> reduction in friction at the capstan/knuckle interface if all one is
> doing is removing a couple grams of weight there... much less if all one
> is doing is keeping the existing weight on the capstan but changing how
> much each of the two top action components individually contributes to
> that weight.
>
> Even up at the top where the weight on the capstan can easily get as low
> as 70 grams... a subtraction of a couple grams of whippen weight only
> reduces the total weight at the capstan by just under 3 %.  And in the
> bass the total weight reduction would only be about 1 %.
>
> I can certainly imagine how dropping the weight at the capstan by the
> total amount of whippen radius weight (using assist springs) might
> significantly affect friction there, but then you are reducing weight at
> the capstan by significantly more in that case.  About 25 percent in the
> above example... and say around 10 % in the lower bass.  Still... seems
> to me the bulk of friction in the action is to be found elsewhere.
>
> In your looking into all this, have you and Don tried simply removing
> the hammer all together and attach comparable weight to the jack top to
> see what friction change there is in a <<with knuckle/jack friction and
> without>> scenario ?
>
> Cheers
> RicB
>
>
>     I apologize Ric. To do this more"scientifically" you should of
>     course remove
>     lead from the key before/after hooking up the spring or after removing
>     weight from the wip in order to maintain a constant BW. This is
>     something
>     Bob M and I discovered in our class recently in Oklahoma. We now use
>     models
>     to teach these principles, made by the Florida State piano
>     technology grad
>     program, with exchangable shanks having 15, 16 & 17 (10) mm knuckles
>     (constant StrikeWeight), movable captstan boats, asssist springs,
easily
>     removable and replaceable leading, and we also introduce the cut
>     punching
>     and balance rail shimming techniques. Used to be hard to get these
>     things
>     across but thanks to the models we have arrived at a real method for
>     teaching these concepts. And we are discovering additional benefits
like
>     "wow where did that additional friction reduction come from?"
>
>     I agree with you, it must be a slightly higher Ratio than we would
>     like for
>     a happy marriage with the SW, but it appears nothing is to be done
>     on this
>     account. It has, however,  provoked some interesting discussion.
>
>     See ya on the web,
>     Chris Solliday