Re: [ATM] ATM Digest, Vol 36, Issue 1

["Arjan te Marvelde" <arjan.te.marvelde@hetnet.nl>]

Hi John,

> Hey, how much did you have to pay to get that name?

You might have guessed: nothing! It is a much overloaded acronym. In fact it
really is AJtM...

> that it doesn't pinch up the sides. Mine touches 50%. Is that what you
mean
> by as a V?

I was trying to figger out the force distribution along the mirror edge.
There are a few  ways you can apply it, the U (i.e. 50% around), the V (i.e.
less than 50% around) or Nils Olofs way using two strings appr. 25% around
centered around the + and - 45deg positions.

Being a master of physics it should be peanuts to write it down right here,
but it's been a while since I practiced it (18 years).

The pics your posted at http://www.johnspics.com/hi/edge_supports.jpg are
quite interesting. I can however make not much sense of the units: why would
a cosine (fig 8) force distribution be 10 times as bad as a raised cosine
(fig 10)? And then, the half cosine (fig 9) is again better than the cosine,
which is opposite to what you would expect.
Anyway, conclusion of the article seems to be that point supports on the
edge are far worse than a sling. Also, all examples apart from fig 14 show
intolerable deformation of more than half wave.

Your U would be represented by fig 11.

   AtM

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