[ATM] Focal Ratio for a Fast 24" & Bob Cox

[Peter]

I've done a 16" F/2.5 in BVC.   For this, it was necessary to have the 
blank slumped.   My understanding, is that the outer layer on BVC is 12mm
thick.   The Sag on a 24" F/3.3 is 11.5mm.    This could be a
problem.    

Thanks Steve for this note of caution. ASM Products (the maker of BVC) is no
longer around but it looks like the business was sold to AJ Telescope
http://www.ajstelescopeworkshop.ca/. His web site indicates that he
suspended sale of BVC for some reason. I sent AJ an email last night but no
reply as yet. I'll try calling tomorrow.

I measured the top lamination layer to be approximately 0.400".  I will be
disappointed if I can only go to an f/4 (0.375" sagittal).


Peter