Re: ATM Re: astigmatism with a sling?

[Andy Saulietis <iss@pvtnetworks.net>]

Nils Olof writes,

>there are more than one way to skin a Newt. Somehow it seems to me sheet
metal would tend to slide by its weight, and then tend to lift the mirror
edge when loaded. I haven't actually tried yet, but it seems to me a sling
made from any of the recently proposed no-stretch wire materials for
pole-and-wire tubes would be just as useful for a mirror sling, avoiding
this problem (I guess you could fix it to the mirror edge in the right
place with a few pieces of duct tape or so).

I've had success using roller chain for
edge slings - does not stretch & is flexible
in the desired direction(s). I use a piece
of thin Teflon between the chain & glass, the
chain is midway on the edge of the mirror.
I used a piece of 5/8 chain for a 32" x 4"
primary (*overkill*), but bicycle or 1/4" chain would
be adequate for most amateur mirrors.



 



Andy Saulietis
ISS Enterprises
39 Silver Fox Trail
Mayhill NM 88339
505-687-3067 voice
505-687-3021 fax, call voice or e-mail to set up
e-mail: iss@pvtnetworks.net