[CAUT] lighter touchweight

[Chris Solliday]

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
----- Original Message ----- 
From: "Richard Brekne" <ricb at pianostemmer.no>
To: <caut at ptg.org>
Sent: Saturday, October 20, 2007 3:39 AM
Subject: [CAUT] lighter touchweight


> Hey Chris
>
> Comments intertwined below.
>
>
>     Yes Ric, i too would like more info to get the basic out of the way,
>     a good
>     marriage of Ratio and StrikeWeight, but that doesn't seem likely in
this
>     case.
>
> Yep, I suspect a mismatch too, but who knows ? Hazarding a guess I'd say
> the R was high for the SW's... or the fellow just wants a really light
> touch.
>
>     As for capstan/wippen friction, a lighter weight resting on the
>     capstan will result in less friction. Don't change anything else and
>     put in
>     a lighter wippen or one with an assist spring and measure it. With
>     an assist
>     spring picking up much or all of the weight of the wippen (and that
>     doesn't
>     have to be adjusted that tightly to accomplish it), as some have
>     erroneously
>     imagined the rep spring to be doing, you will read less friction
>     statically
>     and perhaps wonder what happened but I assure you that the effect is
>     much
>     greater when the action is in motion and felt by the player.
>
> Well, I have to admit I've never actually bothered to check out a static
> difference in friction for a couple grams difference in whippen weight.
> I've noticed a bit when disengaging assist springs visa vi coupling them
> to just lift the whippen weight.  But cant say I've noticed very much
> static difference.  I will look closer at this in the near future tho,
> since so many of you seem to relate similar experience.  Never say never
> as the saying goes :)
>
>
>
>     Further not all of them like it. Ask me how I know. In other words
>     you can give the same BW
>     (with same Up and Down) with springs and lead as you do with just
>     lead and
>     the noticable difference will be two things, mass of the key at
>     break away
>     and less friction. Where else is it but at the the place you pulled
the
>     weight off of?
>
> Well, measured friction change from lighter whippen weight I'd agree has
> to be coming from the roller / capstan interface.  But I've always been
> under the impression that the major objection pianists have to light
> whippens has more to do with the fly away affect, and how the things
> reset on the capstans.  What do you mean by <<mass of the key at break
> away>> ?
>
>
>     I truely wish we had a way of measuring kinetic component friction
cause
>     then I'd have charts and graphs and really kick your butt! But think
>     about
>     it and tell me where I'm wrong because I'm just a beginner and I
>     start over
>     fresh everyday anyway.
>
> Grin... kick away Chris.  But you are no beginner... tho that wad of
> <<what I know and dont>> humility in your back pocket serves you well
> and its one of the things I like very much about your posts. Keeping
> oneself firmly on the learning bench is probably the absolute best tool
> at our disposal.
>
>     BTW just asa a teasing aside, the newly designed wippens that Jamie
and
>     Bruce are developing for M &H from synthetics are lighter, several
grams
>     lighter, than standard and the reason is???? So they can put the
>     weight into
>     the hammer and reduce friction at the capstan which by the way is
>     anodized
>     aluminum and of course very light.
>     Best wishes to you,
>
> Hmm... but er... weight a minute here.  A capstan for a note with 40
> gram BW and 30 grams FW is balancing a lot of weight on the capstan yes
> ?  With a blank 0.5 key ratio we have 140 grams sitting there.  How much
> difference can a couple grams weight difference make in friction at the
> capstan / whippen interface ?  And what difference at all can there be
> in friction here if the weight is the same, but composed of different
> amounts of SW and WW ?
>
> More Musing from Bergen
>
>
>     Chris Solliday
>
> Cheers
> RicB