At 7:55 AM -0500 1/7/03, Farrell wrote:
>Indeed you are right. I have a 1947 Baldwin M in my shop also. The
>Baldwin string height is 7-5/8" and the Knabe string height is
>8-3/4". It appears that most of the height is made up in tall key
>height at the rear and the long capstan. Why should this be a
>problem?
Look at it as a tall inner rim. This nineteenth century feature is
equally worthless from the standpoint of good action design, as were
the contemporary fat keyblocks on short pianos.
>In this particular case where the capstan contact is above
>the magic line, I should be able to shorten the capstan a tad and
>put on a wippen with a taller heel. Doesn't that fix it?
The top action stack is familiar looking, with nothing in the spread
or distance down from the string plane nearly as dramatic as the
height of the capstan above the key balance point. You can certainly
find your lines of convergence, but these lines will be "looking
uphill" because of the elevation of the rep center in relation to the
key balance.
The higher uphill these line go, the more the rotational motion of
the capstan distributes itself in the horizontal (sliding) vector
instead of the vertical (lifting) vector. At 45º, they are equally
balanced, I can't recall ever seeing a key/rep centerline more than
30º. But it likes to be horizontal. As the line steepens, your gas
mileage drops .
There is the possibility of buying the longest molding hammers
possible for as much hammer bore as possible (with requisite tail
bore). That way, you could lower the stack. (A little ways.)
>You mentioned upper limits of string height. What is that? And
>exactly what does a tall string height do for you or how does it
>work against you? I do service a old Decker grand that has a
>mile-high string height (don't have the measurement - but it was so
>obvious with just a casual glance).
No limit to how high you can make them. Think the the upright actions
mounted on dowel/wire. Yamahas get pretty tall but I don't think
they've ever gone to an "abstract" ticker linkage to the key.
The best that I can guess about the high string plane was that it was
how they visualized piano cases 120 years ago. Del's Visual Bulk
Factor, optimized according to their taste
>What I really don't understand is the knuckle contact being very
>low. It doesn't even meet the magic line at letoff. What would cause
>that & how to fix?
Ron Overs showed us that you have to completely redesign the rep to
make that happen. Most manufacturers and action designers have simple
walked away from this requirement. Speaking of which, heres where a
lever arm dips way down from level (at rest point) and faces a great
deal of sliding motion do get it started. Either you buy Ron's action
or you live with it. Like next week's garbage.
Bill Ballard RPT
NH Chapter, P.T.G.
"Trust me, you've got all the equipment, You just need to read the manual"
...........Reese Witherspoon in "Legally Blonde"
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