Re[2]: [ATM] lurie-houghton progress

[Richard <cnc@cncservo.co.uk>]

Hi Kevin,

Sunday, July 31, 2005, 4:42:29 PM, you wrote:

KW> How thick would the glass need to be for a 13.25"? 
KW> Would this design work on a primary of f/3.12?  

It would work fine, design equations at the URL below, or MODAS
does a reasonable job or designing a Houghton Cassegrain. You
probably wouldn't want to go below about 8mm edge thickness for
the BCX corrector or 8mm centre thickness for the BCV corrector,
which means you would get them both out of 1" thick blanks if
you were careful. The thickness of the correctors has little or
no effect on the outcome.

http://members.cox.net/rmscott/lh_scope/lh_design_equations.html

-- 

Best regards,
  Richard in the UK



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