Patriot Observatory
So a while back, I had an idea for a super low budget domed observatory that could be improved on over subsequent years, using wood frame construction for the bottom half and an 8 foot 2v geodesic playground 10 sided dome for the top half, as an alternative to the plastic domes that, if I could afford one, I would have ordered instead.
I finally got to building it, and here is how it is constructed.
First came putting together the dome itself, took an hour or so, easy but tedious. After that was assembled, I took some measurements, and put together the wall sections into two halves. Using those halves, I cut the floor, and using the cut floor, I laid out the floor frame.
For the initial stage, there is no pier, and the dome lifts/rolls off. There is a gravel pad with 3 concrete blocks set in the ground for a tripod, and holes in the floor for the tripod legs to go through, isolated from the structure. There is a French drain 10 feet uphill, so water issues aren't a big concern. The floor is framed with 2x8's and 2x6's with 3/4" subfloor, with enough space in the middle of the frame to dig a pier without taking down the structure when I get to that point. The lower walls (also 10 sided) are 32" high and framed in 2x4 with 7/16" sheathing.
There is plastic sheeting under the Subfloor and inside the sheathing, and tyvek over the sheathing, with corrugated vinyl siding. The dome is currently covered by a tarp with a number of attachment points. The first iteration had the dome lift arms at 4 feet long, which made it much too heavy and unreachably high at the apex, so I shortened them to 3 feet. It's easier to lift, but no longer fully clears the structure when open, and consequently gives a steeper view angle to the north. The lift mechanism operates with 4 hinges, it lifts and rolls to the north with a similar view angle to the treeline. The rolling is performed by large skateboard wheels on a totally warped 2x12 leftover from another project a couple years ago.
The first iteration had the tarp tucked in between the dome and the walls as seen above, but my original idea for keeping water out involved an interior lip all the way around, which turned out to be impossible when combined with the dome lift mechanism, as well as being excessively damaging to the tarp itself when the mechanism was operated, so it's now fully exterior, hanging 4" below the top of the walls, hemmed via grommets, though I may take it off and stitch the hem at some point.
In the next couple of years, I plan to cover the dome with plywood, cut a slot and add a rotation mechanism, as well as add a pier, and eventually automate the dome rotation. This is the reason I decided to build it the way I did, instead of using a plastic shed or similar. This way, the basic structure is already present and ready, whereas with a cheap garden shed, I would have had to build the whole thing later, and have a rotting plastic shed to get rid of to boot. It also (in my opinion) looks nicer out in the front yard than a random plastic garden shed.
Power is supplied by solar, both a small 300w dedicated system as well as the main house system, with generator backup, which is rarely used except in winter. There are no utilities at the street, so we have to be self sufficient for power and water.
I am considering a powered lift/roll solution using linear actuators, but have not fully worked out how to do it.