clues to grand hammer pitch

[Barbara Richmond]

----- Original Message ----- 
From: "RicB" <ricb at pianostemmer.no>
To: <pianotech at ptg.org>
Sent: Tuesday, March 13, 2007 5:23 PM
Subject: clues to grand hammer pitch

SNIP
> Nothing says you have to follow any particular method... but I would be
> skeptical to their being any standard set of rakes to fit string angle
> because that would require that every instrument was built with the exact
> same string to keybed distance, the exact same string angles, and the
> action fitted to these exactly the same every time.  Not too likely.  Tho
> some methods of putting the instrument together in the first place yield
> more consistent results then others.

Umm, I didn't expect a standard--especially since I was told there
wasn't... ;-)


> I generally approach this whole kind of problem by taking what's in front
> of me and setting bore lengths to a 90 degree angle with the shank when
> the hammer is in contact with the string.  I almost never change the stack
> height, and I am unconvinced that when I have done so I really gained any
> significant benefit... tho no doubt there are extreme cases where this
> might be truly desirable.

Well, the action just, uh, looks goofy.  These huge, bulbous hammers, what
looks like roughly carved/adjusted flanges.  It plays surprisingly well
except, of course, for that checking problem.  :-)   There wasn't anything
obviously wrong about the jack at rest or play. The customer stressed that
she
wanted the piano to perform well for at least 20 more years.  I asked her
if it had ever performed well since it was rebuilt.  Umm, no, not really.  I
looked at the <original> wippens and thought 20 years of hard play left in
them? Oops, there was a jack that had given up the ghost.  And then there
are
those weird hammers?  They had that cheap upright hammer sound.  I
shaped a section, needled a bit and they were much improved, certainly.  But
I have no idea how long the voicing will last.  I told her to play it a lot
and we'd see how the voicing holds up.  I'm reasonably sure a more lush
voice is possible for this piano and certainly a better touch.


> Considering this is your first attempt at a relatively involved action
> rebuild,  I'd go with this procedure as its perhaps the easiest to get
> right and it will yield very good results.  You might want to post some
> action height figures tho if you want more input from folks.

The bass string height measured 8 1/4".  (Is the plate high?--the pin
block was replaced by the same people. The down bearing was sort
of wavy, but the sustain was OK.)  The hammer flange pin was 5 5/8".
The bass hammers were bored at 2 1/2".

> Bob Hohf has
> a very exacting method for getting an optimal set of action heights, and
> his article series on the subject might be good reading for you if you
> want to get really into it.

Thanks, I'll look it up.

> Other wise...  just make sure you have a good spread, and that the capstan
> placement yields appropriate jack travel for the regulation specs you
> want... i.e. key dip, letoff, blow distance, and amount of aftertouch.,
> and go with a bore distance that fits the formentioned.
>
> Thats my advice at any rate.

Thank you.

> One other question... .just to be certain.. you find your bore length by
> subtracting the distance between the hammer shank center and key bed and
> the string height and keybed right ?

That's right.

>You did this and Ron says its
> greater then usual and thats why you suspect a stack change?

Yes, I thought a stack change was a possiblity.  I didn't tell Ron what I
found, he just told me what they usually run (give or take some)--
2 3/16" bass, 1 7/8" treble.

> If so you
> could always look for other signs of a stack change... like shims under
> the bracket feet.  Subtract their thickness and see if that gets close to
> Rons <<ususal>> ... you see where I'm going here yes ?

Yes, I see, but I thought it might have been lowered--or the hammer rail
planed down, etc.

There was another thing that struck me as unusual,--I suppose it could be
normal, but I've never run into it before.  The back rail didn't extend
past the keys.  I was going to set the action up on it (like one does to
insert balance rail paper punchings) and the keys hit the keybed.
Obviously, whatever it was that I intended on doing, I didn't do (and now I
can't remember what it was!).

All of this could be for naught, but it's always good to start thinking and
try to be prepared--just in case I get to muddle my way through it.  I'll go
do my homework now...

Thanks,

Barbara Richmond

.
>
> Cheers
> RicB
>
>     >Assuming you don't have any clearance problems
>
>     > between the belly rail and the plate up in the higher treble...
>    as for
>     > example some Bechsteins at the top and at the break between the
>    top and
>     > treble sections,  you can approach this several ways.  My default
>    is to
>     > make the hammers 90 ¤  with the shank at string contact.
>     >
>     > You do know how to find the proper bore length yes ?...
>
>    Yes, but I'm wondering if the stack height has been tampered with. The
> bore
>    length now is greater than what Ray told me it usually runs.  I'm
>    having a
>    feeling that I'm going to go through a growth spurt on this one. Or,
> the
>    owner may decide to just might have me work with what is there and
>    get it to
>    play the best it can.
>
>     >
>     > If you are replacing much of the action, I suppose you should
>    deal with
>     > your checking problems after you get all the new parts on.
>
>    Yeah, I was just trying to prepare myself if this part of the
>    proposal is
>    accepted.
>
>    Thanks,
>
>    Barbara Richmond
>
>
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