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Re: [ATM] Astigmatism on thin blanks
Russ-
I will accept your intepretation of my answer. But answer for me two
questions: are there none of us who can afford to buy a one tenth thickness
ratio large blank, and does anyone know the answer to the previously posed
question: what movie, and what actor/actress said: "Sometimes the way
forward is the way back". Yes, I have been diagnosed as obsessive compulsive
(one of the less troubling components of my defective head programming,
circuitry).
I know at least one of you has seen this movie, or this is a much smaller
list than I think it is.
I gave away $4,400.00 worth of custom made Classical Cassegrain optics to
Frank Ward. Can I afford to buy those kind of optics, even those kinds of
blanks, now? No. Can I afford to give them away? Not if I don't have them;
after Theresa died, only 22 months ago, I gave away my house, and my brand
new (but unuseable, because of my rapidly declining health) Meade LX-200 12"
Schmidt Cassegrain, for which I built a runway to get it to the center of
the back yard, to be able to see through the tunnel of trees. As I said, I
have now given away $8,800.00 worth of astronomy gear; not including the big
mounting on my pages here:
http://www.atmpage.org/contrib/Harbour/Sym.Eq.Mntng.html
Which I did, after all, give away. Not monetarily valuable (could not sell
it; but 3,500 hours to build it)
http://www.atmpage.org/contrib/Harbour/Photos,%20med/ROLL2JPEG-28.JPG
http://www.atmpage.org/contrib/Harbour/Photos,%20med/ROLL3JPEG-7.JPG
I am only passing through life; I will take nothing with me, and have next
to nothing now. Except mostly, my friends on this list, who do me great
honors regularly. Thanks, Russ, for answering my post.
The quote, the line from the movie- are you game?
R-101
P.S.- Remember, I figured a 20.5" f/5 1.38" thick glass, and got no
astigmatism. My only thin blank, that large (for a customer). If a mirror
maker has EARNED bragging rights, I believe he is entitled to tell his
success story. No astigmatism, but I would not put a mirror that thin in my
dream scope. I had my dream scope(s). Now I like to write for you guys, if
you like to read my ramblings. And try to avoid pain. Wellness to all-
----- Original Message -----
From: "Russell Jocoy" <russjocoy@hotmail.com>
To: "ATM list" <atm@atmlist.net>
Sent: Wednesday, May 21, 2008 7:26 PM
Subject: [ATM] Astigmatism on thin blanks
To all, David Harbour made a statement of fixing the astig. problem of
thin glass work is to buy THICKER glass. ATM"s in the past had no choice
but to use thick glass, and also that thin glass was TABOO... Thus comes an
experimentation situation....1.. Thick glass is heavy, takes a long time to
get itself stable to the outside temp's....time is important to an observer.
2.. The recent rise in cost of "pyrex" or any "thick" glass has hit the
wallet of the ATM hard, as have other cost's.
ATM's are trooper's and don"t give up that easy.. Thin glass has been
tackled for over 30 years, (ask Mel) Thin glass is not a horror story, and
not a auto astig. situation. The times are a changin'.
Thick glass is available if you can afford it.. Thin glass is available
and the few who go there need to take care, and read, listen, learn, and not
bitch when you don't follow instructions and end up with a monster, Like Bob
May says, The only way you can destroy a piece of glass is to break it,
anything on it's surface can be changed....unless you give up the goat...
Russ
Thin glass within reason can produce a beautiful telescope, I own a 13
inch by 3/4" plate glass mirror that produces fantastic images to the
eye...f4.7 pushed yes, but possible...........
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