Re: [ATM] 40' mirror some ideas

[vorblesnak@peak.org]

Thanks for the link!  I had seen this one before but could never get back
to it.  Who fused the blank?

David Davis
Toledo, OR  97391

> Like this ?
>
> http://www.cablevision.qc.ca/astro/alex-36ins.jpg
>
> 36" dia. x 5" thick, 120 lbs, faceplate to f/4.5, flat back, homemade.
>
> Jean-Guy Moreau
>
>
> ----- Original Message -----
> From: <vorblesnak@peak.org>
>
>
>> Keeping in mind the original discussion.  Why not a two stage approach.
>> Cast the front as a 2" x 40" disk of pyrex.  Then create a cellular
>> blank
>> by fusing ribs and a back to the pyrex front.  The front will weigh
>> less,
>> cool and anneal easier, generally be a better disk to work.  Then you
>> could pick up the thickness needed to combat flex by fusing a structure
>> to
>> the back.  Do it right and you could slump it to the right curve and
>> save
>> on grit and back muscles.
>
>


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