Back to Home

ATM Forum Message

Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education
Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
RSS Button

Home | Discussion Forums | Amateur Telescope Making | Post
Login

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
RE: Need Info About Casting Blanks

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Robert May on September 6, 2000 07:04:57 UTC

Interesting project. Have you done a search on "casting glass" yet on a search engine like Google? Getting a oven large enough to cast the glass is the first problem. Then you need a controller that can drop down through the annealing temp slow enough to allow the glass to properly anneal. I started a search and found an oven for $840 but it`s only about 21" in diameter so that isn`t big enough for you.
I hope that you aren`t including the tools needed in the price of the telescope project!
You can do plate type glass (lots of broken glass is needed as you probably want a 3" thick mirror or deeper if you do a ribbed one like the Hale telescope mirror).
I would suggest that you refrain from fusing glass pieces as Richar Schwartz (sp?) has been that way for a while and he`s already learned that plate glass doesn`t work for that and you need pyrex in order to not have it shatter at the least temp change. He`s had mirrors shatter just from the heat of polishing.

Follow Ups:

    Login to Post
    Additional Information
    Google
     
    Web www.astronomy.net
    DayNightLine
    About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
    Unless otherwise specified, web site content Copyright 1994-2021 John Huggins All Rights Reserved
    Forum posts are Copyright their authors as specified in the heading above the post.
    "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
    are trademarks of John Huggins