[CAUT] Key ratio measurement (was Re: moving capstans question)

[Richard Brekne]

Hi Keith.

I by and large agree.  I dont buy into some of the draconian redesigns 
I've heard tale of. At least not if that means getting into big changes 
in the actions geometry.  Most often that is actually quite good enough 
to get on with.  Making what we have in front of us work correctly is 
the primary task.

That said... evening out Strike Weights to a 10th of a gram is to my 
mind clearly a very good idea... especially if one does correspondingly 
nice balancing on the other end. It essentially is a very quick and 
efficient way of doing the weigh-off to begin with... and we all know 
thats got to be done.  And in the same process one creates an evenness 
of  touch that pianists simply do pick up on.

I do have a scale that reads 100th of a gram... tho I round off to 10th 
of a grams for Hammer Strike Weights.  I'm just that much more certain 
of my figures thats all. A tenth of a gram SW works out to roughly a 
half a gram Finger work. Like the absolute pitch thingy... pianists have 
shown they are capable of amazing degrees of sensitivity in touch as 
well.  A 10th of a gram precision seems a good place to settle on to me.

I'd also like to point out that any move in capstan or knuckle is in 
principle ok.... as long as you know exactly what you are doing and 
why.  I would submit that such moves do indeed constitute at least some 
measure of action redesign tho.  Like I said in my last... Jon Page has 
some very good thoughts on that.

Cheers
Ric B



    Sometimes it cracks me up. Correct me if I'm wrong but are you guys
    using
    scales that have an accuracy of a tenth of a gram? I suggested to a
    friend
    we get the one that has an accuracy of a hundreth of a gram. Your
    hammers
    range from 10 grams down to 5 grams. (give or take) So with 5 grams
    divided
    into 88 increments that yeilds a weight change of slightly more than
    half a
    tenth per hammer. It is senseless to use a strike weight curve
    unless I can
    post hammer weights after the taper like, #1, 9.64 #2, 9.60  #3,
    9.55 #4,
    9.45  #5, 9.49  #6, 9.35

    Now that could read 9.6, 9.6, 9.6, 9.4, 9.5, 9.4 or 9.6, 9.6, 9.5,
    9.5, 9.5,
    9.3. However with the scale we got it makes it possible to really
    dial in
    the weight of the parts. In the run above I can see that i can
    switch 4 and
    5 and being the bass it won't show. A tenth of a gram scale doesn't
    cut it
    in my opinion for the proclaimed smoothness of curve. Essentially it
    all has
    to come out in the wash when the action is reweighed and leaded.

    Really we don't want to redesign the action, we want to make it work
    right.
    We are taking the measurement of an existing action and it doesn't
    matter
    what anybody else gets as the action ratio. 40 people can measure it and
    have 40 different answers for their computer/math models but nothing has
    changed in the action in question. It still has the same ratio it
    had before
    the measurements as afterwards. We have several options. The
    consensus is
    that 4 to 5 leads in a key is two much. I took out 4 pounds of lead.
    We can
    lighten the hammer, we can move the knuckle, we can move the capstan and
    even the heel. Sometimes we can get different whippen configs. Each
    one has
    it's own criteria that has to be considered before using. Key dip
    and blow
    distance really didn't change much with this capstan move but moving the
    knuckle, it sure does.

    Keith