Ditch the tuning pin bushings - One ? at a time

[Ron Nossaman]

>DS comment:
>(Actually sneaking in 3 questions)
>
>Ron, the "Lines of Force" to which I was referring comes from one of Joe 
>Garrett's posting to this thread ( Fri, 11 May 2001 20:56:40 -0700). 

I know, but those are Joe's lines, not mine. He'll have to clear that one
up himself. Joe, are you there? Come explain yourself. Leverage and load
are the bottom line result, so that's my approach to these things.


> The 
>comparison between open face and covered (without bushings) asks to explain 
>the active purpose of the webbing in the support scheme, if same result can 
>be achieved without such.

Well, according to Del, the webbing is there to provide something for the
tuning pins to bear against because the block won't handle the load. That
would be the case with or without plate bushings. With an open face block,
I'd want a lot more than five laminations in my block, especially at the
top where all the leverage compression is.


> Is the open face block installed in a 
>significantly different way than the covered block? 

It's usually cut at different levels on top to extend up to the proper
levels in the tuning pin fields, though that shouldn't be strictly
necessary from a structural design standpoint if the plate is designed
around the flat top block. But then I've never designed a plate. Again,
maybe Del will elaborate as necessary.


> The 'Lines of Force' 
>issue with the tuning pin bushing vs. non-bushing is whether the pull of 
>the strings on the block in the direction of the plate flange is reversed 
>by the pivotal function of the bushings.  Is there agreement on this question?
>
>David Skolnik

Probably not, but I don't now and never have bought the reverse leverage
idea. It presupposes the ability of the pin to pivot easily in the block
for the idea to work, and the leverage pressure on the block drops
dramatically as the pin contacts the plate. Delicately put, I think the
idea is a hallucination looking for participants.


Ron N