Michael,
Imagine tuning an upright piano and placing the hammer on the tuning pin so
that the handle points towards the ceiling. Now, in an impact hammer, the
handle can freely rotate about 30 degrees in each direction before it
catches the tuning pin and exterts force. You can probably imagine what
would happen if the top of the handle were weighted. As the handle is
rotated back and forth, the weight and velocity with which you turn the
handle creates a momentum. The energy created by this momentum is
essentially delivered all at once to the tuning pin, causing it to move all
at once. You grip an impact lever down at the base of the handle (by the
tuning pin) instead of gripping it towards the top of the handle. This
allows you to rotate the handle back and forth by simply twisting your
wrist. It also allows you, if you are average height (which I am), to tune
uprights while remaining seated on the bench. So, an impact hammer for
uprights looks very similar to a traditional lever. For grands, you would
have a problem using the impact hammer as the mass at the end would exert a
downward force which you would need to counterbalance. That's why the
T-hammer was created.
By varying the speed at which you turn the shaft, you vary the impact force
on the pin and can control the amount you turn the pin. For pitch raises,
you twist harder to quickly bring up the tension. For fine tuning, you
twist less, or switch to a lighter weight.
I'm not sure what percentage of tuners use an impact hammer but it seems to
be pretty low. This has always surprised me because I feel an impact
hammer is quicker and more efficient and less tiring than using a
traditional lever. It makes me wonder why the person on this list is
selling theirs?
Corte Swearingen
Chicago
"Michael Gamble"
<michael@gambles.f To: "Pianotech" <pianotech@ptg.org>
snet.co.uk> cc:
Sent by: Subject: Re: Impact tuning hammer.....wanted.
pianotech-bounces@
ptg.org
11/25/2003 12:22
PM
Please respond to
Pianotech
Hello Corte
Thanks for the description....
"Imagine a tuning lever that fits on the pin of the grand piano,"
I always use a "T" hammer in a grand tuning session
" but instead of the handle coming out horizontally (as in a traditional
lever), it goes straight up vertically. At the top of the vertical section
is a horizontal section that is fastened so it forms a "T" with the
vertical
section. "
This sounds like my usual "T" hammer...
"At each end of the horizontal section is a weight that is screwed on."
This where, in my "T" hammer, there is a heavy hammer peen - for belting
pins in...
"These two weights, at each end of the "T", provide the mass for the
impacting of the pin."
So far you've described my "T"! but the peens are not removeable...
"If you've ever used an impact hammer for an upright,"
I haven't...
" you will know why that design does not translate to a grand. It would be
very awkward and
difficult to tune a grand with an upright impact hammer."
Do I read into this that you tune an upright with a form of "T" hammer?
That
would surely be hard on the wrist - the twisting motion I mean...
"The T-impact hammer adapts the impact technique for use with grand
pianos. The impact
design allows extremely minute changes in the pin"
By "minute changes" do you mean "turning"?
" while minimizing twisting and flagpoling."
What is "twisting" - is it the same as "turning" - and is "flagpoling" the
act of pulling or pushing the pin toward and away from you (in a grand) -
or
up and down in an upright? Use of this movement to a minute degree is what
I use to "set" the pin - after "turning" it to tune the string.
I may be dense - I cannot understand the term "impact" in this use. I am
biassed by use of an "impact" screw-driver which I use to "start" very
tight
screws - the "impact" is produced by use of a hammer on the top end of the
driver.
"A photo is worth a thousand words!..." anon
Regards
Michael G (UK) in the darkness of the Sussex Downlands...
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