FRONT RAIL KEYPIN SHAPE

[Ron Nossaman]

>The real question is, why aren't all balance pins oblong at the top?

Hi Clark, good question. Why not?



>With this arrangement, button and mortise can be mortised with the same
>tool, at the same time. 

You lost me already. Wouldn't the difference in width between the shank of
the pin, and the tip, require a larger mortise in the key body? 


>Not only that, the number of doglegs in a key
>can be reduced since the buttons aren't so compromised in width, and
>therefore lengthening their working grain. Seems to me the extra cost of
>a 0.147" shank, 0.089" tip balance pin would offset the cost of keyplank
>layout, button placement and button trimming, where bushing would be
>directly on each key - before or after sawing.

You lost me again. Given a key headscale, and hammer strike line ... scale
(nomenclature evaporated on me), overall length of the keys, and necessary
key ratio, what choices do you have with the doglegs? Yea, I've seen
instances where the balance pin isn't remotely in line with the key head
and capstan. It sometimes seems to be an attempt to keep the key stick as
wide as possible at the center, presumably for strength, at the expense of
in-line leverage. I don't know if that was really the intent, but some of
them look that way to me. An oval pin might help this sort of thing some,
but it would be better if the leverage points were in line. Also, that
button, if it isn't made out of Styrofoam, adds significantly to key
stiffness, which seems to me to be worth the cost of installation all by
itself. How would you compensate for that stiffness loss?



>Yes, the oblong shape of front pins lend them to adjustment when
>bushings become worn - however, this only compounds the original
>problems of misplacement. 

Misplacement of front rail pins? How, and why?



>Round balance pins, similarly misplaced,
>exhibit deformed bushings (perhaps more, due their tighter radius and
>smaller travel) - ideally they should be positioned to intersect a
>variable touch point and fixed jack or capstan position, according with
>the leverage required by the action.

Right, which will require doglegs in the keys to accommodate differences in
spacing and section breaks. 



>Disgruntled,
>
>Clark

Ah, there we are. We could all use a good thorough re-gruntling from time
to time. Surely someone will post us a url to the on-line gruntler.

Ron N