Re: [ATM] The 15.5 inch Ultrathin, more pictures

[GF <gary@rcn.com>]

It was just something we've wondered about.

I was supposing that the flat could be, say 5 feet off the floor - where 
the mirror would lie - and be tilted 45 degrees. Assuming a 15" f4 - 
which I think is at least close to the specs of the mirror in question. 
The tester would be at the same height, 5 feet. Wouldn't that require a 
7.5" x 9" or so flat in this case - not overly huge? Less if you mounted 
your tester higher. Most photo tripods would get this high and can be 
stabilized a variety of ways, though a more stable support would be 
better. We have a dresser that's almost that high. If your house has a 
staircase maybe you could get by with a smaller flat? If you have 10 
foot ceilings, maybe even use the diagonal?

Mounting would depend on the flat, but something with a cross bar should 
be able to hold whatever you epoxied to the back of the flat. It doesn't 
seem any more dangerous or difficult than having a secondary mirror in 
your scope - just larger.

Gary Fuchs





Nils Olof Carlin wrote:

>Gary F wrote:
>
>"Would it be possible to test the mirror horizontally with a flat 
>above at 45 deg? This could shorten the floor space needed as 
>well. "
>
>Yes, but it will tax ceiling space instead - unless you have a huge 
>flat, and how would you support it horizontally?? - who hould set up a 
>test rig and work it at something like 10 feet above the floor? If you 
>can, fine.
>
>Nils Olof
>
>  
>
 
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