measuring ratios, (was popsicle)

[Erwinspiano at aol.com]

Hi Ric
  Hey good food for thought but if 1 mm of key movement  raises the hammer 
6mm , to me  that is  a 6 to 1 ratio.  When I use the spurlock tool all I'm 
doing is using it as a  quick trouble shooting indicator as to how much  trouble 
the action is going to be. Ie will longer knuckle to center be required  or 
capstan move..  As you stated this morning.
  Ed ...I like your thoughts too. The use of smaller  than a 6 mm block takes 
us in the direction of action  acceleration.
  Dale Erwin

Hi  All

As long as we all remember that the <<ratio>> defined  this way (ala 
Spurlock)  is not the same ratio relationship as  Stanwoods Strike Weight 
ratio we are ok here. Stanwoods ratio is about how  much weight at the 
key front is needed to balance whatever radius weight  the hammer has out 
there on the end of that shank.  More specifically  we are talking about 
how much weight would be needed to bring the action  into the half blow 
condition in a frictionless world.  That is not at  all the same thing as 
how much distance the hammer moves for any given  amount of key travel.  
In fact, if you were picky enough about your  measurements you would find 
that if you measured for a 8 mm key travel  compared to 4 mm key travel 
you'd end up with two different figures there  too.

There is an approximate translation that generally works fair  enough... 
and in any case if you are shooting for some BW in an action  re-do  you 
nearly always end up within a couple grams (nearly always  heavier) if 
you've calculated with the distance ratio as your figure for  R.  Its a 
good thing to gain a basic idea of your general leverage  zone by doing 
the Spurlock thing.  But if you plug that value into  Stanwoods formula 
to arrive at a FW figure for some targeted BW, you are  going to have to 
go back and add some few grams of FW in the end.  On  the other hand... 
the error created is consistent... so you can either  live with it and 
still have an even result... or try and compensate a bit  by 
approximating a translation from one R to the  other.

Cheers
RicB


 
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