Thanks for the numbers Gene.
Well, you do have a bit of a high ratio... (low leverage as Jon puts
it). Tho its not way up there by any means, except for note 88 which
spikes much higher then the rest. Still you are about 6.1 it looks like,
which is consistent with everything except the blow and dip. This got
David Love scratching his head as well I see. Somethings amiss to be
sure. A 6.1 Balance weight ratio that requires 41 mm blow and 10.5 mm
dip to get minimum aftertouch. A few thoughts:
-If you are going to increase your blow distance and keep the key
dip the same... or even (preferably) allow for a shallower key dip
setting if desirable, then you are going to have to increase
leverage. (Which should be high enough already for that goal... but
set that aside for the moment)
-Your Front weights are reasonably light all the way. So you can
increase them somewhat to compensate to maintain your desired BW.
- Moving to a 17 mm knuckle would give you a good increase in
leverage, I agree with John that moving the capstans further out is
probably not a good idea.... tho I have run into as high as 0.6 KR
(you wrote it the other way... and that would be 1.66) A larger
knuckle, as Jon says, may also be a good idea if the ones you have
are small and/or worn.... didnt catch if you are using new shanks here.
This said... as both David and Jon echo, it looks like something isn't
quite right. You seem sure of your measurements so, the next thing to
check is your lines of centers. David mentioned this and I'd agree. You
may have a geometry problem of some sort... Jon mentioned Bob Hohfs
article and the possibility of changing the stack height... the spread
you give seems reasonable, but you want to take a look at the jack angle
at the rest position and capstan / whippen cushion intersect with their
line of centers at half blow at least.
To answer your direct question. It is my opinion that a blow distance
of 41 mm is a bit to low. Gives you no room at all to change touch
characteristics... especially with deep key dip already, and it will
limit power more then I would want. What to do depends on whats causing
the inconsistency mentioned by all three of us.
If you like the touch as it is, and are only worried about the short
blow / deep key dip (and I would definitely want to know the reason for
that in this case myself) then I suppose you could live with things...
but I'd be skeptical myself. That blow/key dip doesn't add up with a
high action ratio.
Interesting side point.... this kind of reveals a major type flaw in the
idea of relying on simple distance ratio measurements to establish the
ratio. Jons initial guess (as I interpreted it) took for granted a low
ratio instead of the high ratio we are looking at.... tempting to do
when you just hear the key-dip /blow numbers. Dale hopped on that with
both feet... and he's stated several times he just measures key movement
for hammer movement to get his action ratio. Seems on the surface of it
to show what many of us have felt for a long time now. Stanwoods
approach to measuring the ratio is a superior diagnostic tool for
analyzing an action.
Cheers
RicB
******My samples were not all C's but they are all naturals, first
and last
in each section. - here it is:
note# SW FW BW KR WW
1 10 30.1 41.5 .55 16.4
25 10 26.7 42.5 .52 16.4
27 9.3 23.8 39.5 .54 16.4
45 8.4 15.5 44 .54 16.4
47 8.7 16.6 42.5 .53 16.4
66 6.8 7.7 42.5 .54 16.4
68 6.5 6.5 41.5 .54 16.4
88 5.0 6.8 36.5 .53 16.4
Note that the WW value is the same because it is the average - the
range was
from 15.9 to 17.2
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