Aftertouch, WAS Re: Action Geometry Consistency

[Bill Ballard]

At 3:01 PM -0500 5/16/03, Avery Todd wrote:
>Bill,
>
>I don't understand this. The aftertouch is "part" of the dip. It 
>sounds like you're regulating
>them independently!

I sure am. It's the greatest thing since sliced bread (and I can 
support that claim <g>)

The dip can be whatever it and the blow and LO have worked out 
together. The aftertouch is always found measuring up from the key 
dip, with a standard amount, say 50 mils. That's the aftertouch 
interval of the key stroke.

I'm not actually setting the dip to a specific amount. I'm letting it 
be a function of aftertouch. Aftertouch in turn is a function of 
blow, LO and action ratio. The first three determine how soon the 
jack fly will hit the LO button. The key travels a little deeper into 
dip and at a certain point, it comes through the bottom end of 
escapement. At that point my finger measures 50 mils of travel. The 
dip ends up being 50 mils below the bottom side of escapement.

To review dip is an automatic function of the end of let-off, which 
in turn is a function of blow, LO and action ratio (Strike Balance 
Ratio). Since aftertouch is determine by the action as a whole , with 
specific figures for blow and LO, dip can be what ever it is going to 
be. But by definition, dip is to be 50 mils below the bottom of 
escapement, because the action is based on a uniform aftertouch.

There's plenty of good reason to make the foundation a uniform 
aftertouch. So much depends on it. Repetition considers it to be 
unnecessary return travel  in resetting the action, especially for 
quick & deep repetition. But without it, LO, drop and check can't 
happen. Dip of course is the basis for damper lever height and check 
height. But these are peripheral compared to what is lost when after 
touch is not provided. So why not take advantage of the ability to 
set aftertouch by itself, and make sure that t is even.

At 10:20 AM -0500 5/16/03, Bradley M. Snook wrote:
>I went back a read my original email; I guess it may have been slightly
>ambiguous. The intent behind my question was "how can I fix the problem,"
>not "how can I compensate for it." Compensation is something that I do all
>the time. At this point I am looking to approach the problem from a
>different perspective. Before I try all kinds of crazy things that may or
>may not work, I thought that I might first learn from what others have
>already tried.

And you've certainly been given alot of ideas in the last few days. 
If you can get rid of such errors, by all means do so. But you might 
keep track of your time. Beyond a certain point (ie., eliminating the 
out-layers), the time could be more fruitfully spent on "eliminating 
the error" in voicing. That's what pianists are after.

At 6:24 PM -0500 5/16/03, Cy Shuster wrote:
>Is there any benefit to a consistant hammer line, other than how it 
>looks?  (Perhaps, as you suggest, it's simply an indication of other 
>adjustments?)

I'd prefer to have it a straight line. Much easier to restore when it 
wears and sags. And I still like  the reverse "economies of scale" to 
be had in the dip. 0.125 of blow divided by an action ratio of 5.5 is 
22.7 mils, which is 5.8% in the dip, but 45.4% of a 50 mil dip. Put a 
20 mil cardboard punching on a table and run your finger across it. 
Imagine the dip decreasing by that amount, then the aftertouch 
decreasing by that amount. If the aftertouch is uniform across the 
keyboard, the pianist won't notice the change in dip. They will 
notice that all the things which depend on uniform aftertouch are 
working.

They'll also notice more the time you put into voicing.

IMHO.

Bill Ballard RPT
NH Chapter, P.T.G.

"Can you check out this middle C?. It "whangs' - (or twangs?)
     Thanks so much, Ginger"
     ...........Service Request
+++++++++++++++++++++