Tuning Hammer and Technique for Novice

[SUSAN P SWEARINGEN]

Good point Bill.  I actually carry three tuning hammers in my kit; a upright
impact lever, a T-hammer, and a traditional hammer.  I usually test a new
piano with the traditional lever and if the pins are loose, I will use the
traditional lever instead of the impact method.

Corte Swearingen
----- Original Message -----
From: "Bill Ballard" <yardbird@pop.vermontel.net>
To: <pianotech@ptg.org>
Sent: Sunday, June 16, 2002 11:07 PM
Subject: Re: Tuning Hammer and Technique for Novice


> At 4:54 PM -0500 6/16/02, SUSAN P SWEARINGEN wrote:
> >Another complaint I have heard is that people don't want to have to
> >learn two hammer techniques since >the impact hammer is not suitable
> >to grands, only to verticals.  I felt the same way until I had
> >Mike >Swendsen of Canada make me a T-impact hammer for grands.  This
> >hammer works beautifully and Mike >did a wonderful job in designing
> >it.  Yes, you have to carry two different hammers in your kit, but
> >that >hasn't been an issue at all for me.
>
> The fling which your fingers give the the impact centrifuge is simply
> oriented to a different plane by the wrist, moving from vertical to
> grand. The arm, from the wrist up, is generally not involved in the
> generation of force being thrown into the system, so it can be where
> ever it (and the wrist) will feel most comfortable. Thanks to the
> efficiency of the system, the arm and wrist can be comfortable and
> let the finders do all the work.
>
> In practice, the extent to which this is workable is a matter of
> tuning pin torque. The impact approach is wonderful at being able to
> bounce a blow against the corners of the tuning pin and avoid, in the
> process, any twisting or bending of the pin. These are the aspects of
> the mechanics of tuning which degrade the accuracy required by the
> stability of the tuning. Impacting minimizes them.
>
> However, another aspect of the tuning's mechanics is where the tuning
> pin torque sits, in the range between mushy to noticeably two-phased,
> through tight-gripped to snapping. The fling of impacting is nearly
> useless to gage once the pinblock grip falls below that threshold
> amount which overcomes the block's grip on the deep end of the pin.
> This is generally around 50-60 "/#. At higher levels of pin torque,
> the amount of torque surplus to the threshold level, which in the
> non-impact, firm-gripped approach is simply thrown into pin twisting
> and bending. Not only is that a potential liability, it's also a
> waste of energy.
>
> In the impact approach, the process of overcoming the pin twist is
> still there, only this time instantaneous (or at least faster than
> human perception). The immediate amount of force required to overcome
> the block's friction grip is quickly applied, and the surplus goes
> directly to the turning the pin.
>
> The real challenge in learning the impact approach is how the results
> change as this point of "break-free" droops lower and lower.
> Remember, the hand has contact only when it's throwing the handle,
> and not at the point of impact. So the hand has no idea which that
> "break-free" amount is, which is spent up front, and as a result, the
> proportions of the "entry fee" and the remainder which actually does
> the work. As the pin torque continues to droop lower, tuning gets to
> be more and more like striding across ice in ball-bearing boots. Lots
> of unexpected motion.
>
> Not that I especially like tow-torque tuning, but some of our most
> stable pianos have surprisingly relaxed pinblock grip.
>
> Look in the 2-3/91 PTJ for an article on the coordination of string
> and tuning pin friction in the mechanics of tuning. (By me.) The
> energy we put into the system is actually supplied to the tuning pin
> friction with the hope that the surplus will overcome the string
> friction, with enough remaining from that transaction to move the
> string the desired amount. Impacting makes sure that extra amounts of
> force don't get get stored (or more likely, wasted)in the springiness
> of the pin and string. But you forfeit that direct contact with the
> pin which informs you of the pinblock's grip.
>
> Bill Ballard RPT
> NH Chapter, P.T.G.
>
> "I'll play it and tell you what it is later...."
>      ...........Miles Davis
> +++++++++++++++++++++