clues to grand hammer pitch

[RicB]

Hello again.

I think we can assume we are talking about the rake... but you might ask 
him to make triple sure :)


     > i.e. the angle they are to
     > the shank ?  If so... I don't think you need to worry about what
    they are
     > <<supposed>> to be because there are several quite acceptable
    schools of
     > thought on hammer rake.

    Would you like to list them?  Though I suppose I could do a search
    on rake.

Well, there are probably more then I know about... but one is to have 
the hammer at 90 ¤ to the shank at string contact, then some folks 
believe they should be slightly leaning forward, then there is the idea 
that the hammer should be 90  ¤  to the string itself, and adjust the 
rake accordingly.  Sounds like perhaps this is what Ron is saying Knabe 
used to do... but not having much experience with Knabes and not knowing 
their history well enough I cant be sure.

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 consistant results then others.

I generally approach this whole kind of problem by taking whats 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 benifit... tho no doubt there are extreme cases 
where this might be truly desirable.

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.  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.  Other wise...  just make sure you have 
a good spread, and that the capstan placement yeilds 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. 

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

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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