[pianotech] action ratio

[Richard Brekne]

Hi Steve.

I'd say there were a lot of possible reasons for what you came up with.  
I find there are two good ways of coming up with a fairly accurate 
picture of the <<action ratio>>.  Either measure the individual levers 
and multiply the result of each, or do Stannwoods BW.  Note that these 
are in fact (most often) different ratio quantities. The BW ratio is an 
expression of what it takes to put the action into a state of 
equilibrium.  Measuring the levers directly is an approximation of the 
engineered ratio... which really needs to take into consideration the 
angles the parts have installed into the action... but you can get a 
decent ball park figure every time just measuring the parts directly. 
That is to say... you wont come up with a 4.4 ratio when in reality the 
ratio is 5.8.  You might be a couple 3 points off... (significant enough 
to be sure) but not more.

Cheers
RicB