[pianotech] high leverage action

[Richard Brekne]

Hi Frank.

I would have thought the same until the example given by Gene. Seems to 
provide a contradiction whereby clearly the weight ratio was the more 
dependable. Of course we have to await more info from Gene on this... 
but I'd actually like to get to the bottom of what causes the apparent 
discrepancy between the two protocols.

Stanwood will be the first to acknowledge that ratio taken his way 
versus a distance ratio will yield different results at least as often 
as not, if not more so, and he has done some comparative work to find a 
happy marriage between the two. But I dont think he's seen such an 
extreme example as Gene's seem to be at the moment.

Cheers
RicB

    .....Dale Erwin’s practice of measuring hammer movement for a
    predetermined key movement is much superior for determining the
    ratios. This automatically makes allowance for the vertical and
    horizontal components of movement of every action part. Similarly,
    calculating the ratio from weights rather than distances returns
    more accurate values for action ratios. The problem with physical
    measurements is that it is often difficult to accurately measure,
    visualize alignment, avoid being deceived by parallax influences,
    etc.....

    Frank Emerson