Keys and MOI

[Richard Brekne]

Go one better Ed... switch hammer number 2 with hammer number 88... and
then compare both to hammer number 1. Try and conciously feel the
difference between MOI and WEIGHT by varying how much and how fast
finger force you use.

Incidently... the Bosendorfer I mentioned had a Vienna type action, but
with very heavy hammers and no key leading. The equivalant of the
capstan on this action was at the very back of the key... yeilding
realllly high key ratio. The Hammershank ratio was roughly comparible to
modern instruments, and so you ended up with a DW my little brass DW set
couldnt measure... that is to say in excess of 70 grams. I didnt check
UW but it was no doubt up in the high 40 range at least.

Lowest possible inertia for that ratio and set of hammers... and boy was
it heavy to play. However... if you played at what I would term "medium
hard" too "hard",  you began to not notice the weight so much... and
thats right in our present ball park.

Cheers
RicB

Ed Sutton wrote:
> 
> Jim wrote-
> >
> > If you want to feel what the MOI of the action feels like, that's easy to
> > do.  Simply do some rapid repeats down on key #1, and then do the same
> > thing on key #88.  If your balance weitght is consistent, and nothing is
> > sluggish, the big difference you feel will be the difference in the MOI.
> > It's just that simple.
> >
> > Jim Ellis
> >
> Jim-
> 
> Great example! (And so obvious we should have been born knowing it!)
> 
> So, if we can feel this difference, we could make a simple test by altering the
> lead placements on two adjacent low bass keys, keeping all other parameters equal,
> and then see if we can feel anything approaching the difference we feel between
> 1-88 or even 1-44.
> 
> Ed S.
> 
> _______________________________________________
> caut list info: https://www.moypiano.com/resources/#archives