Re Light Action (HELP)

[Kenneth Sloane]

                      Subject:                              Time:  5:27 PM
  OFFICE MEMO         Re Light Action (HELP)                Date:  1/20/96

---------------(portions of) Original Post----------------

>A piano can be on spec in regards to downweight and feel dynamically
>anywhere from heavy to light.........

....Finally, what is the exact relation between weight and repetition? Is a
very light action invariably connected with slow repetition, maybe due to a
low up weight?

----------------Reply------------------

Here at Oberlin, we have experimented with different up weight/down
weight/friction range/lead position (close to balance rail or close to front
of key)/etc. combinations. I don't have the time (or energy right now) to go
into lots of detail about the different combinations we have explored, but I
will mention one variation that I suspect will be interesting if not
illuminating.

We recently fit a Steinway "B" with a new set of keys installed on its old key
frame. The hammers for this action had been installed about five years ago and
were not completely shot. After the new keys (unleaded) were fit properly to
the old hammer stack (with the five year old, filed hammers that were now a
little on the light side), I wondered what sort of upweight/downweight (UP/DW)
specs the action would have and how it would feel. I don't remember the exact
numbers, but the bass had somewhere around 100 DW, the treble in the 70's, and
I believe the UW was over 50 throughout most of the keyboard. Well, none of
the pianists that played it thought it was heavy, nor did I, even with my
meager playing skills. It was an easy piano on which to play loud and fast
(low inertia), and it repeated very well. However, some pianists (myself
included) thought it felt funny when playing slowly. I imagine this was
because a high static or balance weight is more readily perceived during slow
playing. And guess what? Some pianists really liked it.

I later weighted the keys on this action to have a DW in the mid 60's for the
bass to around 60 in the treble. The UW was 30 or more everywhere, and I
installed the weights close to the balance rail for low inertia. The piano
still feels good when playing loud and fast, repeats very well, but does not
have the funny feeling during slow playing. I may add that I have worked on a
Yamaha nine foot piano that had an action with a DW in the mid 60's and an UW
around 20. The piano had small hammers and very few weights in the keys (makes
for low inertia), and virtually every one liked the action on the piano, even
though they thought it ws light. I would characterize the repetition on the
instrument as not tremendous but certainly adequate.

To sum up, I find that DW/UW specs are not nearly as important as the presence
of the "right amount" of inertia in the action. Unfortunately for the
technician, however, it is very hard (if not, practically speaking,
impossible) to quantitate. Not only is the actual mass of the components in
the action critical but also the distance of the components from their pivot
points and the ratios built into the levers of the action. This may sound
incredibly unscientific, but I feel I can determine if the inertia level in a
piano will be acceptable to a majority of pianists by using certain licks.

As far as repetition is concerned, keep the checking high and you can get away
with murder in all the other areas. How's that for an over simplification?

Ken Sloane, Oberlin Conservatory