bore distance: was Re: hammer replacement

[Newton Hunt]

If the shank is allowed to go past horizontal and certain amount of energy
is lost by doing so, so I have been told.  The idea is to prevent the shank
to go past horizontal to expedite it's return for a repeat.

SOme European makers have done as you said but usually because the action is
too low or the strings are too high.  That is their solution to an
awkwardness and I don't think that was the original intent of the engineer.
Engineers like straight lines and ninety degree bends.

As has been pointed out what ends up in the back shop often has little
relation to the engineer's intent.  Here and there as well.

Bechstein and Masons are notable exceptions.  I have seen Bechsteins that I
had no idea what so ever what they intended and couldn't figure out how they
arrived at their solution.  Weird pianos!

I do want my hammers understriking a tiny bit initially so that after the
first filing they will be striking properly and will do so for a long time. 
By a little bit I mean that extra .5 mm or 1/32" of extra bore.  More than
that causes lots and lots of regulation problems.  Ask me how I now someday
and I will regale you with hours of woe and agony.

> I guess the question is, what do you sacrifice 
> in regulation to get that?

The action was designed to perform certain things at certain times and
changing the regulation will compromise the engineer's expectation.  Until
someone can prove to me that compromising a good design (yeah, a big
assumption on my part) I will continue to do it the old fashioned way.  To
reduce one regulation point (or increase it for that matter) will compromise
something else somewhere and you have lost something, power, repetition,
control or lower dynamic.  Compromising the regulation compromises geometry
and I am not ready to change that unless someone can prove to me that what
they say works.  Study action geometry, Pfieffer and others, and you will
get the idea that those actions could have been set up right in the first
place (but may not have been) and to make changes you better well know
exactly what you are doing and what the consequences of considered changes
will be.

In other words, don't mess with it is you are ignorant.  I say this not from
the peak of the ivory tower but from the basement after having fall there
with lots of aches, pains and blood.

The above is why I decided to bore my own in the first place.  I can do far
better work than most factory "borers" can, for a particular piano.

> In practice, you would be able to control ppp playing 
> better by not having to start the key with a certain amount 
> of force and  back off as the resistance diminishes.

I do not quite understand this.  Friction, static friction, balance weight
and parts condition control more than anything else I can think of.  These
issues I understand fairly well, mostly.

Anyway, I have done a lot of boring and I have arrived at what I do by
imperial experience and reading and feedback from others.

Also I am a stubborn s.o.b.

Have a nice weekend.

		Newton