Solicitation for Comments

[KenMiller]

I am starting to plan the construction of an observatory.

Like everything else regarding astronomy, I know very little.

I am thinking 12' diameter concrete slab with an AstroHaven shell. I'd really appreciate any observations regarding the AstroHaven shell.

My area of greatest concern is the piers (I'm planning for 3).

I am tentatively planning on using 12" diameter concrete piers isolated from the pad of the observatory by an expansion joint. The piers would be sunk into the ground 4'.

Is there any better pier solution than a big chunk of concrete?

Will the expnansion joint be sufficient for vibration isolation?

The pier positions I am planning are 2' from the edge of the dome and 6' between piers. Do these sound like reasonable spacings?

All observations and suggestions welcome!

[Spoonsize]

http://www.astroskies.com/forum/viewtopic.php?t=181

you may have to register to view it.

The link is to a forum discussion of construction of my observatory. The base is 10 feet in diameter, and it transitions to the 8 foot diameter of the Explora-Dome. I have one 12" diameter pier in the center. I use one mount to support a refractor and SCT but not at the same time.
The dome and base are large enough for me and one telescope. Even if the dome were of the clam shell variety, it would still not be large enough for two scopes.
I suppose a 12 foot diameter MIGHT be large enough for 2 piers, but I doubt there would be enough room to support three telescopes and related accessories.
I built a wood floor to separate from the concrete pier for isolation.
I really do not believe 2 feet from the edge would be enough room for a scope on a pier.

Steve

[Frank Boyle]

That will be a killer setup Ken. Please post pictures once you get everything all setup.

Frank Boyle

Originally Posted by KenMiller

I am starting to plan the construction of an observatory.

Like everything else regarding astronomy, I know very little.

I am thinking 12' diameter concrete slab with an AstroHaven shell. I'd really appreciate any observations regarding the AstroHaven shell.

My area of greatest concern is the piers (I'm planning for 3).

I am tentatively planning on using 12" diameter concrete piers isolated from the pad of the observatory by an expansion joint. The piers would be sunk into the ground 4'.

Is there any better pier solution than a big chunk of concrete?

Will the expnansion joint be sufficient for vibration isolation?

The pier positions I am planning are 2' from the edge of the dome and 6' between piers. Do these sound like reasonable spacings?

All observations and suggestions welcome!

[KenMiller]

Thanks for the link Steve. You did a really nice job!

Sounds like I should be planning more like a 4' radius around each pier.

Hmmmm.

[Spoonsize]

Ken....Set your scope/scopes up with the counter weight bar horizontal and OTA also horizontal. Measure out from the center of the mount to the ends of the bar and OTA, and this will give you an idea of how much room you'll need.
Thanks for the comment on the obs.

Steve

[KenMiller]

Well... I don't have the larger scopes yet - although one is one the way. That's kinda the purpose of the observatory.

When I got started with this I selected equipment that I could reasonably carry in and out each night. Now I want to upsize

Guestimating on their mounting points, a 5' radius would handle the largest and a 4' radius the next largest.

The math on all these inscribed circles was aggrivating, so I fired up TurboCAD. Looks like I can do one 5' radius plus one 4' radius plus one 2' radius mount inside a 12' x 18' Astro Haven clamshell with space for a 4' desk and chair.

But to get in and out of it appears to require a base for a door - which I guess means a raised floor and taller piers. I guess it's time for a call to Astro Haven.

[JMS]

Hello, For separation of pier and concrete floor, before pouring floor, wrap pier with a styrofoam, 1/2" to 1" thick. After pouring floor you can burn it out and replace with a foam rubber material. Homosote is dense and might transfer vibration.

Joe

[KenMiller]

Originally Posted by JMS

Hello, For separation of pier and concrete floor, before pouring floor, wrap pier with a styrofoam, 1/2" to 1" thick. After pouring floor you can burn it out and replace with a foam rubber material. Homosote is dense and might transfer vibration.

Joe

That's a great tip! Thanks Joe.

[KenMiller]

I haven't been making much progress on this because Astro Haven no longer offers the size dome I'd like. But I'm not yet ready to give up on the full clamshell design (I just don't like those roll-offs).

In the mean time, I've had it with realligning every time I want to image.

So, I've decided to put in a concrete pier, see where that takes me as far as additional piers and later put the building up around it/them.

[Spoonsize]

What mount are you going to use??