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Old 17-01-2011, 10:00 PM
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David Fitz-Henr
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Join Date: Aug 2007
Location: Bowen Mountain
Posts: 837
Quote:
Originally Posted by Visionoz View Post
David

Great read on your ATM astrograph - just a query on what's the advantage of a conical parabolical mirror design as opposed to a standard parabolical? - I'm curious to know if weight-savings is one of its advantages or are there other technical benefits?

Cheers
Bill
Well, there are a few advantages to a conical mirror:
  1. Lower mass (approx 60% of full thickness conventional mirror) which means less weight.
  2. Lower mass also means quicker cool-down times. I've read (I think on R.F. Royce's site) that the figure behaves itself better during cool-down period as well.
  3. Simplicity of mounting. No need for flotation cells and edge supports, and when mounted in the way I describe below, there is less freedom for the mirror to shift during use.
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