Design

After two years of setting up and tearing down clear night after night, I finally decided finally to build a small low-cost roll off roof observatory at my house. The only suitable place was the spot I was currently imaging from – a wooden deck above the family room (an extension of the original house). This provided good views south, east and north-west, with only the northern part of the sky (close to the meridian) partially blocked off by a 150 year old oak tree – one of the original Newlands Oaks planted during British Colonial rule of the Cape.

My original plan was to construct two piers to carry my equipment, but this would have required either laying a concrete slab below the wooden decking or alternatively constructing a steel I-beam structure to support the piers. This more than doubled the total cost of the project.I already knew that the deck was stable enough to support long exposure astrophotography, provided that I did not walk on it during an imaging session and since the equipment would be controlled over my home wifi network from inside the house, I decided to simply reinforce the floor of the observatory to provide a stable enough platform for my imaging rigs.The materials for the walls and roof of the observatory are made from refrigeration panels. This provides good protection from the heat of the summer and keeps the inside temperature within a range of 15-30C all year round.

Humidity is regulated using a dehumidifier and when the roof is closed it is fixed at around 50%. A wifi enabled switch (Sonoff) allows me to turn the dehumidifier on and off remotely.

The roof slides open and closed on a set of steel rails and is driven by a standard gate motor. Automation is provided by an Arduino and a series of magnetic sensors which monitor the state of the roof (open or closed) and the mounts (parked or un-parked). The observatory can be up and running within a few minutes and is controlled over Splashtop streamer (or Teamviewer) on my laptop (or desktop) computer from the comfort of my living room (or anywhere in the world). Proceedings are monitored using a security camera, which is mounted on the side of my house and looks down on the observatory.