[pianotech] Hammer Blow

[Ed Foote]

>>My question; Does anyone or is there a way to calculate the blow 
distance or do you just go with about 45 to 47mm range?<<


Greetings,
    The optimum blow distance will allow optimum keydip and aftertouch 
without hitting the rest cushion or being more than 10 mm off of it.  
The sharps can't really be more than 1/2" (13 mm) high, and if you 
subtract how much you want showing at full depression, you can then see 
what the blow needs to be by setting let-off and after touch.
    I think, ideally, after dip and let-off are set, the jack should 
just hover off the back of the knuckle when the hammer is held in 
check. Chris Robinson showed a regulation procedure that set blow by 
positioning the jack in the mortise. With inconsistent actions,I think 
it is better to define some of the specs as functions rather than as 
parameters.
Regards,

Ed Foote RPT
http://www.piano-tuners.org/edfoote/well_tempered_piano.html







Al -
High Point, NC