[CAUT] Hammer Alignment

[Chris Solliday]

Isn't that the great part of this business we are engaged in, we are always
learning new things or looking at things in new ways because someone turns
the diamond for us and looks at the issue from a different facet than we
were looking at?
I've been a proponent of channeled shanks to improve tone (6:3) for several
years on this list and in real life too, and remain so, however, they do
require more attention to the burning angle during the first few years than
the thicker hex do. Thanks to Ron for the little tweak of over turning and
then coming back, sounds promising to me.
Chris Solliday
----- Original Message ----- 
From: "Overs Pianos" <sec at overspianos.com.au>
To: "College and University Technicians" <caut at ptg.org>
Sent: Sunday, March 26, 2006 2:02 PM
Subject: Re: [CAUT] Hammer Alignment


> Hi Jon,
>
> You're certainly not crazy. This stuff really happens.
>
> I've noticed that shanks can move after a careful setup also. I've
> suspected for a while that it may be caused by the settling out of
> internal growth stresses, which occur over the first year or two,
> causing the burning angle to change.
>
> Always with new pianos, there is a tendency for more movement in the
> first year. The full regulation at the first year usually involves
> quite a deal of hammer alignment. The reg' at year two, considerably
> less. Thereafter, annual reg's will require burning angle adjustment
> of only a couple of hammers.
>
> I think two factors are a play here.
>
> Firstly, the above mentioned stress relieving as the shank ages, and
> secondly the operation of hanging the hammers, and in particular the
> casting to adjust the burning angle.
>
> It is just about impossible to hang a set of hammers which require no
> post-casting to adjust the burning angle. I believe it is important
> to try and hang the hammers such that there is a minimum of casting
> required to set the burning angle afterwards. The important and
> mostly overlooked first step, is to get the shank travel as good as
> possible before the hammers are hung. This will allow us to hang the
> hammers in such a manner as to reduce post-casting requirements
> dramatically. Furthermore, when gluing the hammers, I don't try to
> glue the hammers so that they look nice and parallel initially. I set
> each hammer initially vertically, then check the burning angle by
> moving the shank upwards and visually checking the burning angle
> while the glue is wet. If necessary I'll adjust the angle of the head
> to eliminate a burning angle problem. This is important. The
> requirement to angle the hammer indicates that there is travel error
> at the flange which wasn't eliminated before the hammers were hung.
> If the hammer angle, for each, is adjusted while the glue is wet to
> eliminate the burning angle, the final hammer alignment can be
> achieved after the set is hung by packing the offending hammer
> flanges to correct the travel problem. This approach greatly reduces
> the need for casting the shanks all over the shop after the hanging
> is done, and will significantly reduce those problematical alignment
> stability problems that you have mentioned. The casting operation
> itself requires bending the shank to somewhere that it wasn't sitting
> at previously, when in a state of zero external stress. There is
> always a slight tendency for heat-bent wood to spring back some, over
> time. Therefore, less casting results in greater long term stability.
>
> I have also found that when casting is required, a more stable result
> is achieved if the shank is cast a little too much, then cast back a
> little to where we want it.
>
> A well hung set of hammers can make the job of the touch and tone
> regulator so much easier. Getting on top of the skills required to
> hang a set of hammers is very satisfying. But the learning seems to
> continue on. That's another of life's little pleasures.
>
> Ron O.
>
> >Is it just me or am I crazy but I've noticed a misalignment
> >of hammers after a year or two.  By this I mean that the
> >hammer has leaned towards the treble such that it requires
> >re-setting.  Angled too much for burn-in.
> >
> >Could it be that the shanks develop a twist, warping
> >in a clockwise rotation as viewed from the front?
> >Gravitation whiplash from the rotation of the earth?
> >
> >The travel is not the culprit. When installed, they were dead on.
> >I've noticed this developing more so on Renner shanks than Abel.
> >It's disconcerting to find your laborious efforts gone astray.
> >
> >They're not bored off center. I can't recall ever finding
> >ones that leaned counter-clockwise.  Oddly enough,
> >the bass doesn't seem to exhibit this phenomenon.
> >
> >A newish M needs most of the top two treble sections reset.
> >Yesterday I reset at least a dozen on an L which had new h/s/f
> >three years ago.
> >
> >One could past it off as a poorly hung set
> >but I know that was not the case.
> >--
> >
> >Regards,
> >
> >Jon Page
>
>
> -- 
> OVERS PIANOS - SYDNEY
>     Grand Piano Manufacturers
> _______________________
>
> Web http://overspianos.com.au
> mailto:ron at overspianos.com.au
> _______________________
>
>