[CAUT] aftertouch (was Re: F..riction)

[Ed Sutton]

I use an approach derived from John Hartmann's articles in the Journal.
Drop is usually set very close, as Fred Sturm describes.
I have a test weight which weighs 365 grams.
I have made Y shaped slotted aftertouch gauges of different thicknesses 
(.030, .035 and .040 inch) depending on what is desired for a particular 
action. The handle makes it easy to slip under the key.
With the gauge on the keypin, aftertouch is correct when I can set the 
weight on the key without escapement, and then cause escapement by tapping 
the weight with a capstan tool.

I recently made a set of gauges which work very nicely. For example, if 
.040" styrene is the chosen aftertouch for the set, make 5 Y gauges of the 
styrene, then glue punchings, green, red, blue and .020 cardboard on the 
styrene gauges, one of each.
Then, if aftertouch tests too wide for the .040 standard, try the other 
gauges so that if, say, the gauge with blue punching "passes the capstan tap 
test," you know that a blue punching is what's needed on that note to make 
it pass at .040.

I prefer removing the naturals and doing all the accidentals first, adding 
punchings and flipping the cloth punching on top, then pulling the stack, 
adding the naturals and finishing aftertouch.

Also, I recently bought a set of WNG regulating tools, and am surprised at 
how they have made regulating faster and less stressful. They are 
ergonomically correct for the various tasks they do, so that the hands are 
supported in correct relation to the action stack.

Ed Sutton


----- Original Message ----- 
From: "David Love" <davidlovepianos at comcast.net>
To: <caut at ptg.org>
Sent: Monday, December 13, 2010 5:48 PM
Subject: Re: [CAUT] aftertouch (was Re: F..riction)


> The procedure I use is similar to Ed's. The .0030 punching (or whatever 
> your target is) is cut so that it can be slipped in and out from under the 
> key easily. The permanent punchings are built up until one achieves 
> escapement (hammer just falls) with moderate pressure on the key. Thus the 
> aftertouch (key travel after escapement) will be equal to the thickness of 
> your removable punching.
>
>
> David Love
> www.davidlovepianos.com
>
> -----Original Message-----
> From: Fred Sturm <fssturm at unm.edu>
> Sender: caut-bounces at ptg.org
> Date: Mon, 13 Dec 2010 14:48:01
> To: College & University Technicians<caut at ptg.org>
> Reply-To: caut at ptg.org
> Subject: [CAUT] aftertouch (was Re:  F..riction)
>
> On Dec 13, 2010, at 2:00 PM, David Love wrote:
>
>> This system is a good one and gives very uniform AT. I like .030 but
>> you do need to stay on top of the blow distance.
>
>
> With this kind of precision in measurement, it is important to know
> exactly from where you are measuring. I assume it is from the very
> moment of (or really barely before) escapement, or when the jack
> reaches its very highest point. The point of contact of drop screw and
> jack tender comes a little earlier, as another possible place to
> measure, and one can also measure from the point at which the jack has
> just finished escaping. With a gauge under the key, the key hits the
> gauge and the jack is at its highest. Squeeze the punching and
> escapement starts immediately. At least that is how I do that when I
> do it (which is rarely).
> For myself, I like to feel through the contact point, compression of
> springs, rubbing of the jack along the knuckle (all of which are
> tactile resistance of one kind and another), and then feel a free drop
> of key of a certain range of size, which is really a tactile judgment
> (and negotiable within limits). With a relaxed and sensitive hand lay
> the fingers on a series of keys (3 - 5, naturals separately from
> sharps), with damper pedal depressed, lower the keys until you feel
> the contact point (observe how high the hammers are, something like 4
> - 5 mm from the strings). Now press through each finger in turn,
> feeling for an even "bump." With practice, you can feel variations of .
> 005-.010". It's a good way to even naturals and sharps. Final check is
> to take each key through escapement (slowly and controlled) and then
> press to the bottom and compress the front punching a bit. The hammers
> should each rise from drop the same amount, not much but definitely
> some (1 mm?).
> Regards,
> Fred Sturm
> fssturm at unm.edu
> "Travel is fatal to prejudice, bigotry, and narrow-mindedness." Twain
>
>