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A Hexagonal Observatory
By Marc Stowbridge
I live in rural central New Hampshire, with clear, dark skies and long winters. I didn't want to leave my equipment out unattended on snowy nights as my tripod would sag into the ice by the time it, and I, reached thermal equilibrium. I wanted an enclosure where I could comfortably use my LX-90 Schmidt-Cassegrain telescope, even when there was three feet of snow on the ground. I decided to design and build an observatory that was easy to make, inexpensive, and adaptable. The resulting structure is about 7 ½ feet in diameter and has walls about 4 feet high. It is designed to be somewhat portable, in that I can prefabricate the sections at home and assemble it somewhere else.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Building Details
The observatory walls are made of six 4-by-4-foot sections consisting of siding glued and nailed to frames made of 2-by-4s. Each wall section is mitered and bolted to the adjoining segment. The observatory sits upon a hexagonal foundation made of four layers of interlocking pressure treated 2-by-4s, anchoring the building and providing solid support. The floor has been covered with sand for leveling and drainage, and covered by interlocking rubber mats cut to fit. To help the observatory cool off after hot days, I installed louvered vents in 5 of the walls and a thermostatically controlled wall fan.
The roof is made of 6 trapezoids of {3/8}-inch plywood, and a small hexagonal cap at the top, all finished with marine grade paint. Aluminum struts provide a flange for bolting the plywood pieces together. The roof has an interior support frame made of angled and mitered 2-by-4s with plywood gussets to provide rigidity. When the roof is closed, this frame rests upon the top of the observatory wall.

To support the open roof, rails of pressure treated 2-by-4s extend from the North wall. The roof rides on these rails with simple rollers made of 6 -inch lengths of {3/4}-inch-diameter conduit that turn on a {1/2}-inch conduit axle. The rollers ride right over ice and snow. Safety cables attached to the roof loop around the rails, preventing the roof from blowing off in a gust of wind. A counterweight extends from the roof, making it easy to lift.

 
 
 
 
 
 
 
 
 

Inside the Observatory
My telescope sits atop a 39-inch-high pier made from a length of aluminum highway light pole, bolted to a 150-pound bucket of concrete. The pier is closed with a disk of plywood at the bottom and is filled with sand to dampen vibration. The same bolt and hand-wheel found on an LX90 tripod secures the scope to a wooden plug fitted to the top of the pier. A 9X14? cake pan between the scope and pier serves as a very convenient accessory tray.

Preparing for a night of observing takes only a few minutes. In winter, preliminaries consist of shoveling a path to the door and sweeping the snow off the roof. After unlocking the doors, I remove the turnbuckles that hold the roof closed. Then, by lifting a handle on the roof?s interior, I walk the 20-pound roof up and over the telescope, and onto the support frame. And just like that, I?m all set to power up my scope and enjoy the night sky. I like showing my friends the surprising things above us. By keeping the setup time to a minimum and making the surroundings comfortable, we're able to focus, as it were, on the sky.