fork mounted 9" refractor

does anyone have any ideas of fork mounting a 9" F/12 lenght 96" weight 100 lbs refractor or would it be wiser to do this on a equitorial mount? thanks john

John,
With such a long scope, I'd think that you'd be struggling with balance issues constantly if fork mounted, unless you built a cradle and could slide the tube fore and aft in it. Also, large amounts of the sky would likely be inaccessible because of interference between the fork and the tube. I think a GEM is a much better solution, though it's gonna have to be a big one!
Good luck!
Tim

John,

I built a GEM for an 8.5" f 12.5 refractor out of 3/4" alu plate with 3" pillowblock bearings. I'm saving up for drives / gears, which alone will cost maybe $ 2K. The GEM on homemade pier is over 6' high and I still need to lie on the ground to view near zenith.

This really needs to be a folded setup. I have a flat mirror, which was very expensive, 6" diameter 1/15 wave PTV of which only the central 5" will be used.

Unless you wish to use low power for wide field views exclusively, you will want a motorized drive. You can do this, should you fold it, like a Dob, with a motorized platform. This is likely the most economical solution despite the expense and difficulty of obtaining a large, high quality secondary.

James Adams

yikes! That's a big scope. I can't say I have any particularly good suggestions (much less any relevant experience...), but my first thought would be a horseshoe mount.

Just out of curiosity, where did you find an objective of that size?

Regards
Duncan