Weighty Problem

[David C. Stanwood]

Dear Newton,

I just have to say there are two aspects in action design that effect
touch.  One is geometry which the efficiency of the interaction of
coinciding arcs between parts that move against eachother.  The other is
the leverage yield, which is the multiplication of the key, wip, and shank
leverage and its relation to the strike weight.  Weight and leverage can
often be changed to improve an action and should always be looked at.  We
do a lot of action reconfiguration and hardly any of it comes under the
heading of geometry.

David Stanwood



>From: nhunt@jagat.com (Newton Hunt)
>Subject: Re: Weighty Problem
>
>Jerry, reread my post most carefully.  I have been in Jack Wyatt's class
>and was greatly upset that misinformation of such a kind was being
>desiminated by a PTG member and sanctioned, by default, by PTG.  He is,
>very simply, wrong.  You CANNOT increase the performance of an action,
>like a auto engine by detuning it.
>
>If you consider the extreme care in design and installing a good action,
>it cannot be improved by changing it's geometry.
>
>Some action, to be sure, can be improved by careful measurement and
>geometry restoration, but NOT by changing, willynilly, such geometry.  
>
>If you wish to make such changes do two things;  
>	1. Carefully measure up and down weight.
>	2. Carefully, by machine, measure repitition.
>
>After making such changes take the same measurements.  Then you can
>explain how the changes effected the action.
>
>You will find that the difference between up and down weight will be
>less, a loss of effeciency.
>
>You will also find that repititon will be reduced, a loss of effeciency.
>
>130 to 190 years of evolution of action design and refinesments cannot
>be improved, without very careful analysis and comparison to action
>design and installation procedures.  Parallel blocks, levels, jigs and
>other such are used to carefully install an action in the factory. 
>Without the same tools and knowledge it is difficult in the extreme to
>determine if any changes will possitively effect action performance. 
>These measurements were made without hammer shanks and damper heads in
>the way.
>
>	Newton
>	nhunt@jagat.com
>