[pianotech] Best way to change touch on Yamaha Grand

[William Truitt]

"- Move the key stick fulcrum point on the center rail. You can accomplish
that by putting a shim near the pin (in front or behind, depending on where
the ratio needs to move). This method is very effective in its ability to
shift the ratio. You may want to study how the hole in the key will move
relative to the pin and new fulcrum point. Most people who use this method
don't report any problems."  Vladen, could you explain a bit more completely
how you go about doing this?  I am having trouble visualizing your shim -
fulcrum in terms of material used and its co-existence with balance rail
punching and felts.  Thanks.

Will Truitt


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of V T
Sent: Wednesday, January 06, 2010 5:00 PM
To: pianotech at ptg.org
Subject: [pianotech] Best way to change touch on Yamaha Grand

Hi Joseph,

Here are a few ways to do it, in no particular order:

- Move the key stick fulcrum point on the center rail. You can accomplish
that by putting a shim near the pin (in front or behind, depending on where
the ratio needs to move). This method is very effective in its ability to
shift the ratio. You may want to study how the hole in the key will move
relative to the pin and new fulcrum point. Most people who use this method
don't report any problems.

- Move the capstan/heel contact point. This is more work and you have to
make sure that you have enough room on the wippen heel to make good contact.
Some people angle the capstan so they can make use of the last bit of felt
on the heel.

- Move the knuckle on the shank. Very effective if you can still regulate
the action after you do this modification. I would study the regulation very
carefully before committing to this.

If you change the fulcrum point or the capstan position, there will be
slight difference in what the modification will do to the sharp keys vs. the
naturals. It's good to at least think about that before moving either.

I wonder if you can explain the second question, I am not sure I understand
it well enough to answer.

Vladan

=======
"Pardon a very simplistic question, but do you mean that "action ratio
reduction" is accomplished by movement of the fulcrum point of a given lever
in question, right?
Another question: At what percentage point "improvement" do we start to see
reduced sliding friction benefits?

Joseph Alkana"