FIRST PHASE, MANUAL OBSERVATORY FOR VISUAL OBSERVATION
I decided to build a dome to try to improve the observation conditions in an urban environment. Light pollution is declared enemy of amateur astronomy. If you live in a city, enjoying dark skies requires spending a lot of time and effort to travel dozens of kilometers with the entire equipment. Of course, there is nothing better than an environment without artificial light, but one way to at least be able to observe from the city is to protect yourself from the surrounding lampposts with a dome.
The dome initially had visual observation as its function and its conception was totally manual: allowing the sliding roof to be opened by hand and rotating the body of the dome with freehand.
The design required a light construction and an adequate size to use it on a terrace. The structure is made of standard aluminum profile with a hexagonal base. The joints are made with the standard parts of the manufacturer of the profiles, it does not require special pieces or tools that are not available to everyone. Both on the inside and on the outside, the profile is covered with thin sheets of marine plywood, to preserve its durability. The plates are fixed with screws to studs fixed in turn with screws to the profiles and all the joints are reinforced with special silicone sealant for exteriors.
The structure rests on a plywood base of greater thickness in several layers, cut formed a ring. In the photos you can see the solution for the structure to roll over the plywood ring and always be centered.
The sliding roof moves on pieces also of plywood as seen in the photos, and is construd by a thin white PVC sheet screwed on two pieces of plywood cut into an arc.
The base is a brick structure, quite light since it is built on a terrace, but it does not need great resistance since the weight of the aluminum structure with the panels is reasonably small, it can even be lifted and removed from the brick base between two people.
The turn of the dome works with simple PVC wheels that can be found in any hardware store, and smaller PVC wheels so that the turn keeps it on the ring.