Re: ATM Jamming of concentric cylinders - Tapered edge lenses and tapered lens cells

["Bob May" <bobmay@nethere.com>]

Actually, you don't want to put a taper on a lens so that it fits into a
cell because of the differential shrinkage of the two materials.  While the
lens and cell will be in nice contact with each other at 70F, the cell will
shrink more than the glass will and at 0F there will be a lot of pressure on
the glass from the physical shrinkage of the brass (or even worse,
aluminum!) which is higher than that of the glass and you can end up with a
shattered glass as a result.
Basically you do need the space so that you can indeed insure that the cell
never shrinks so far as to get under tension around the glass.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net