From The Ground Up

Back in 2008, the building of sage observatory began. The designer and boss-fellow for this whole project is my dad, Steve. My brother Matty, and myself, Drew, have been the doing the majority of the build work, and some minor design, along with my pops.

From the very beginning of this build, Steve had a very specific idea for the layout. The basic plan was a rotating dome on top of a round, stud wall, building. The telescope would mount on 2 piers aligned with the north star. These piers would have to be poured in concrete along with the foundation, but insulated from vibration through the floor. The basic building design would follow standard stud-style construction over a poured foundation.

The pad itself is an octagon, with the piers poured in cardboard tubes and wrapped in foam rubber where they intersect the foundation. The foundation is reinforced with rebar for strength, and to resist cracking in the future. The edges of the foundation are 12-16" deep by 12" wide footers, and the center is 4-6" thick.

The walls are 2X6 stud construction with laminated, 1-1/2" thick, curved plywood top and bottom plates. This allows for plenty of space for wiring and insulation. The walls are be sheeted with 3/8" plywood, inside and out. The top and bottom plates 3/4" plywood, cut and over-lapped, then laminated together. In theory this gives a continuous top plate, and the bottom is interrupted only by the door opening

The roof, or MEGA-DOME, is constructed very similar to an older fiberglass boat. There's a bottom main section, built like a narrow slice through a sphere. On top of this will be long ribs, much like the longitude lines on a globe. There are two 180 degree full ribs, which are double thickness, to act as 'keystone' and as tracks for the main shutter. The shutter itself will be another laminated plywood construction, both for strength, and lightness. The entire dome and shutter assemblies are fiber-glassed on the seams and coated with polyester resin. The entire dome assembly will rotate on driven wheels mounted to the inside of the walls. These wheels will drive a circular 1-1/2" round steel tube, much like a roller coaster track, that's attached to the inside of the dome.

This will, someday, be a fully functioning, modern observatory so provisions have been included for power, temperature control, networking, and internet. The power will be provided by solar panels, wind generators, or a combination of both. The walls have cabling runs for AC power, 12V DC power, CAT5 for LAN, and extra CAT5 for possible control circuitry. There will be a power storage bank, probably lead acid batteries, along with AC inverters and possibly 5V for some of the other electronics. There will be three drive motors for dome rotation, and another two to control scope axis. The 5 motors will have a control computer: probably an old laptop running some flavor of Linux. Some clever control software will control everything, and input will actually be via wireless wiimotes.

Next time: construction begins...