downweight measures, "welding"

[Susan Kline]

Dear List --

I recently emailed Lorlin Barber after she put an enquiry on the caut list
about touchweight. No replies, but we were both interested, so she asked me
to repeat it here. So, here it is, and I have a few further questions of my
own about downweight measurement.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>From: ldb@commonlink.com (Lorlin D. Barber)
>To: caut@ptg.org
>Subject: Measuring Downwieght - the "correct" way
>Date: 31 Oct 1997 09:21:19 GMT
>Organization: Common Link On-Line service
>Sender: owner-caut@ptg.org
>Reply-To: caut@ptg.org
>
>In discussing hammer weight from a reputable Abel hammer distributor/piano
>rebuilder, I was informed that measuring downweight does not mean that the
>gram weight must move the key down to the point where the jack connects with
>the let-off button.
>
>I have always weighted keys, and trimmed hammer and shank weight to get 
>downweight to the point to where it just took about one nudge of the key
>frame to break friction and the key would drop to where the jack engages.
>
>The Abel distributor claims that measurement of downweight is to the point of
>"balance".  This means that what might seem to be a 60 gram weight (the way I
>have been weighing) could be about 55 grams if viewed from the perspective of
>"point of balance".  If the key drops slightly at 55 grams or requires 3 or
>more good knocks to nudge it down to the prelude of "aftertouch" then that
>lighter figure is the "true" downweight. 
>
>What is the consensus on the "technically correct" way to view true
>upweight/downweight 
>measurement.
>
>
>Thanks Much!
>
>Lorlin Barber, RPT
>ISU Music Dept.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

My tendency would be to favor "jack tender touches letoff button" over "key
in balance" as the measure of downweight, because it is much easier to
define and observe. Is this standard? 

Now, my own questions: it seems to me that it would be very easy and
possibly beneficial to measure other things besides the customary "downweight". 

For instance, downweight is measured with the dampers out of the equation.
This makes it possible to do the measurements on a bench away from the
piano, which is convenient. However, if one were to measure downweight in
the piano without blocking or pressing down the pedal, then compare it with
the normal conventional measurements, one would have a figure for how much
weight the dampers were adding. 

I would think this might be useful. One could compare the figures for
different parts of the scale, to see if the weight changed erratically, or
if the springs (where present) were misadjusted. One could compare samples
with different geometries when redesigning a back action. 

Also, I've once heard of measuring downweight all the way to the bottom of
the keydip, right through letoff. Takes a lot of weight! This figure also is
very different in different pianos, and could tell us a lot about the
stiffness of letoff, which certainly affects the touch and playability of a
piano. Once again, measuring and comparing different notes might aid in
achieving a uniform touch. 

Does anyone make measurements like these? Any reason why not?

Regards,

Susan 

P.S. the rest is malarkey, list. Just go back to your keybushing, repinning,
hammer hanging, accounts, phoning, mouse turd removal, etc.

Just for Les and Danny Moore --
>
>> Susan Kiline, I believe, once told me what 'it' is, but 'that' slips my
>> Uh,,,,,,,,  what was it I was
>> saying???????????????????????
>
>Susan, do you want this person or do you already have a pet?  Perhaps your
>boa would like some company while you're out tuning.
>
>Danny Moore
>"I'm lost.  I have gone to look for myself.  If I should return before I get
>back, please ask me to wait."

Well, Danny, most of my pets have had 88 keys. Do you know how many keys Les
owns? Maybe if he doesn't have a scad of practice room keys, etc., he'd
consent to have a short scale, and be a collector's item?

"It" was a note, of course, that Les dropped. Not a good thing in a tuner,
dropping notes. I found "it" way down below the signature at the bottom of
the screen, and returned "it" to him. So that's all "it" was...[eureka!]
sounds like "that" is the same thing! Well, he's consistent anyway.

A lonely boa? Didn't know feathers got lonely!

Danny, you returned momentarily, but didn't feel like waiting for yourself.
You said to tell you that you were tired of looking for you, and wanted some
lunch instead. 

I suppose I should go achieve _something_ resembling work!

 

Susan Kline
P.O. Box 1651
Philomath, OR 97370
skline@proaxis.com


"Enormous amounts of information are available, including, however, very
little reliable data on what it all means."
			-- Ashleigh Brilliant