[CAUT] Upright key weighting

[Richard Brekne]

Hi Todd, Chris... others,

I have to second Chris's basic approach here. Make sure all the parts 
that wear out are renewed. Appropriately firm bushings, both key and 
centers are what factories start with when they lead keys along with at 
least a fairly decently regulated action. You want to make sure all 
these are in good shape before proceeding. I'd also have a good think 
about the voicing.  Pianists sense of touch is far more bound up in the 
overall response of the instrument then I think many of us really are 
aware of. It the piano is very bright then perhaps a down-toning is in 
order anyways and may be much of what your pianist wants.  Its really 
your job to ascertain just what she means by the vague "Its too light".  
What combination of voicing, regulation and leverage issues do you need 
to satisfy her.... without making the piano difficult for everyone else ?

If it comes down to leading alone. There are basically two big 
factors... the actual static down weight and the amount of mass you are 
pushing around.

To keep key mass levels anywhere close to what they are in a grand you 
need leads on both ends of the key lever.  I don't think we have any 
basic guidelines for this yet, but more then 4 ten mm leads in any key 
in the bass graduating to 1 or less in the top is what one often sees in 
grands.  In an upright these will have to be distributed front and back 
of course.

If you have enough mass in the keys already, then removal of front 
leading is your first path. You may have to add a bit to the back end in 
the higher treble. Alternatively, you can add up to 3-4 grams of weight 
out on the whippen lever. That may or may not be a desirable depending 
on the action.

Cheers
RicB


Todd,
I'd recommend overhauling the key bushings and pin holes first. Either 
replace the key bushings and insert new pin holes (Mike Morvan may have 
something to help with that) or at least recondition the pin holes with 
alittle steam or water and apply one or two drops of VS Profelt and the 
appropriate size cauls ovenight. Make sure there is no or almost no lost 
motion at the capstan and level and dip the keys, shallower gives the 
perception of more weight. Then weigh off and see where you are. Back 
leading is standard practice on uprights. It's also worth going through 
all the hammer butt and damper springs to be sure there is enough 
tension. When considering back leading achieving a balance weight of 40 
grams should give a nice firm feel that's without the dampers in play. 
For more in depth you might check with Ric Brekne or David Stanwood who 
have been doing research in this area.
Best of luck,
Chris Solliday