While we're on astronomy, and question for engineers types.

[Tractor]

I'm planning to build an amature observatory in my back yard at some point. Trouble is I want to make the telescopes mounting pier as stable as possible. What is the best way to do this? A 10" or so diameter concrete pier with an adapter plate installed on top of it? Or something like a concrete footer with a large dia heavy steel pipe filled with concrete? I'm thinking the solid concrete would be better myself, but I'm not even close to an expert.

 

It will need to be stable enough to shoot 1.5 to 2 hour exposer photographs (yes the cameras shutter will be open for 1 to 2 hours at a time gathering light.)

I'll probably be using CCD, but its the same basic principle though in CCD I'll be cooling the imaging chip to -40/-20 degrees to make it as sensitive to light as possible. So yeah I'll need it stable enough that bumping it won't hurt as long as no one bumps the optical assembly. The floor of the observatory will definately be separated by rubber (or other vibration damping material) from the main scope pier.

 

Any clues?

 

Evan

[Bgbdbn]

pour a pad and make a pier out of six inch schedule 40 pipe and bolt it to the pad. It wont budge. No need to fill it with concrete. Make sure you get the inclination angle right.

[Tractor]

I'm pretty sure that metal transfers vibrations pretty well. Thats the only reason I'd fill it with concrete. Maybe filling it with rubber or something similar would be better. Hehe I could just spray a crap load of cans of sound deadener into it.

As for alignment. I got that covered. It will be polar aligned and I'll probably do the site survey in the way the ancients would have using the sun and shadows to get some neat angles. It doesn't really need to be that exact since any scopes mount usually has several degrees of adjustment, but I think it will provide some neat insight into the history of the hobby and maybe I'll come up with something interesting for a dedication plate or at least more stuff to add to the picture gallery. Call my backyard "little stonehinge" when I"m done with it:-)

 

Evan