[ATM] Friction and sticking in multipoint mounts

[artbianconi@blast.net]

I've been a proponent of lightweight, thin mirrors ever since I 
took up this hobby. I also recognize the need for a mount that 
will equalize pressures and distribute the loads uniformly so as 
to minimize distortion in the mirror at different elevations.

I've worked a fair bit with FEA software and while I have limited 
exposure to PLOP, I will assume that it's a good program and 
yields accurate information.

However, the problem I have is the assumptions so many appear to 
make about the viability of mechanically hinged support systems. 
For us to build 27 point supports with so many mechanical 
fulcrums and expecting the moments and C of F's to be uniform is 
naive. 

I've buddies that worked as machinists in the prototype shop for 
Bell Labs where exotic designs are (were?) common place. Those 
guys made more money that many engineers because of their ability 
to deliver on super accurate, highly sensitive designs for 
scientific research. And, they had access to a machine shop that 
the guys at NASA would envy and equally large budgets.

When I showed them a typical 27 point mount and tell them what is 
expected, they roll their eyes. They hear ". . . to 1/12th wave 
accuracy"  and they look at me as if I am crazy!

There HAS to be a better way!

Art Bianconi

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