[ATM] Conical Mirrors

[salguod at minbaritm.com (Doug Williams)]

Well, a conical mirror supported by a central post is one solution...but not
the solution I am looking for.  I'm a confirmed "dob guy", and I don't want
to try to grind a conical mirror.  Holes in mirrors (even in the optically
neutral center) don't appeal to me, and yes, I like my laser collimator.

Again, my central post (pin, whatever) would provide no vertical support.
It would provide only horizontal support to keep the mirror from slipping
off of the wiffle tree when the scope is pointed toward the horizon.  I had
thought of the "torque problem".  Yes, the pin might torque the center of
the mirror, but only slightly.  How much depends how the post/hole interface
is engineered.  The deformation would be in the optically unimportant center
of the mirror, instead of in the optically critical edge of the mirror
(where a sling gives support).  Would the deformation be less than what a
sling does?  I don't know, but I think it is worth checking.

I still find it hard to believe that nobody has tried this.  It sounds like
some people have done something pretty similar though.  I guess I just might
have to test my theory.  Since the flange holding the post is only glued to
the back of the mirror, it can't hurt anything to test the theory out.


Doug

-----Original Message-----
From: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net]On Behalf Of
Peter
Sent: Friday, February 13, 2004 13:18
To: Atm
Subject: [ATM] Conical Mirrors

All this talk about innovative ways to eliminate the sling is quite
refreshing. SCT's have already solved this problem by using conical mirrors
with a central hole. The mirror is basically supported by one bolt and no
sling. If done properly the conical cross section of the mirror makes it
stiff and will support itself throughout the vertical to horizontal motion.

Seems like a good solution but you'll have to give up those laser
collimators.

Any comments??

Peter

_______________________________________________
ATM mailing list http://www.atmlist.net/