Heavy action

[David C. Stanwood]

>Date: Thu, 29 Oct 1998 17:32:54 EST
>From: JIMRPT@AOL.COM
>Subject: Re:  Heavy action

>Mark, these three factors are working against you, i.e. console to grand plus
>touch of arthritis.  The console had a much lighter feel/touch than the Grand
>ever will and the customer may never be happy with the feel of the
>grand........... which might become even more pronounced as the arthritis
>progresses....

>Jim Bryant (FL)

Mark,

This may be a plug for my own work but it's meant to be educational to the
list.   The basic action parameters of weight, leverage, and friction may
be altered to make any action feel anywhere from super light to super heavy.

We do a lot of work for clients with arthritis or technicians with clients
that need a very light action.  The solution comes from a altering a
combination of factors.  The formula for a super light action is:

Light hammers
Lowest possible strike weight ratio by moving the capstan/heel line
                               (dip is the limiting factor)
Efficient geometry
Super low front key weight
88 Wippen support or "Helper springs"

Helper springs adjusted to make a Balance weight of 30g 
and friction weight of 10g throughout for a down/up of 40/20
(Some friction is necessary for control, especially in the pp ranges)

Also good for cleints who are weak from cancer treatment or from
other health related problems.

Lightening hammers can have a great effect.  
Just remember it's only one of many things that will lighten an action.
Making hammers too light can weaken the tone on a modern piano.

Make sure you check the key bushing friction first!!!!

The surest fire way of judging key friction is:
Take the key off the frame and place it on the bench so that the balance rail 
hole sits on a wedge or hammer shank across the middle of the hole.  Place
a jiffy lead or leads on the back of the key and position them so that the
key becomes nuetrally balanced and hangs in the air horizontally.
(This means the front weight is zero).

Without removing the jiffy leads place the key on the frame and determine
how many grams it takes to make the key go down.  Place the grams at the
front of the key where you measure touchweight.  

Lets say it takes 10 grams to make the key go down.  That means that 10 out
of the 55 grams of down weight is from key friction.  Easing and dry lubing
the key with powdered teflon can easily bring the key bushing friction
weight down to 1 gram - a decrease of 9 grams.  DownWt would drop to
46grams and UpWt will go up by 9 grams.

Suggested key friction weight zones:

0-2 grams     - low
3-5 grams     - medium,
above 5 grams - high.  

I find the traditional test of wiggling the key or getting it to drop on
the balance rail pins can be inaccurate, even fooling the most experienced
techs.

Test your judgement with the above mentioned test.  I trust numbers well
taken. 
 
David C. Stanwood






ratiocomes from using hammers that are of a low medium range in strike
weight, that is; not so light as to comprimise power and fullness of tone.