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
Thickness Concerns

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Robert May on June 1, 2001 07:41:27 UTC

Back in the old days, the fear was that the glass would sag and some analysis was done and the 1:6 ratio was deemed to be sufficient for mirrors. Now that we have better tools in the hands of the less math intelligent, it's possible to do better studies of deformations in glass and it's been found that the old timers were fairly conservative in their calculations. It's now typical to see mirrors in the 1:10 as more normal and even higher ratios for use with higher support point mounts. The professionals are doing mirrors that are so thin that you might as well throw out the ratio measurement system.
All it takes is a bit more care not to bend things as you make them and to not allow the mirror to take on shapes that are not desired.

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 1994-2020 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