Ad Astra Observatory

I’ll have to see whether the concept has any legs at all when the mirror arrives. If it’s obviously too heavy, I will enjoy having a big Dob around.

My main plan is to keep the OTA as minimalist as possible while maintaining stiffness. Among things I’m going to try, to keep weight manageable:
– A two tube truss might do the trick. This also provides the ability to use flat surfaces to mount against, which could help.

– Keeping the center of gravity as close to the primary as possible. I think that the mount might do better if the majority of the mirror’s weight is directly over the mount head, rather than sprung behind it as would happen with a tube.

– finding materials that are light, stiff, and strong. If I can’t get there with aluminum tubes, I may try some kind of “string scope” idea. Still working that out.

– As a last resort, I may be able to shorten the tube a little by playing around with a tertiary mirror.. I still need to work the math on that one, though.

Anyway, it’s going to be a bit of a project. I hope I can get it finished in time to do some photography this summer.