My flip top observatory is finally a reality. It turned out to far easier than I had expected. I started with this 2.26M x 2.26M shed ...
ABSCO Premier Garden Shed Model 23231G
http://www.absco.com.au/products/index.php?c=14&p=36
Added options
key lock door handle
concrete bolting pack
basic cost $662.73
Total cost including options/gst and discount $793
The local distributor had the option of either free installation or pre-assembled sections. I chose the pre assembled sections so the roof sections could be pre-modified. A word of advice here. It's a very good idea to have a mate helping and holding things up whilst you screw them together. Doing it sole is definitely awkward!!
The roof is an important structural element of this shed and without it the sides need brackets on all four corners both top and bottom (as shown in the pictures) to give them enough strength to basically stand square. Once they are in, the unit is quite square and rigid. The hinges were dead easy. Had some shipping pallet wood that was exactly the right thickness (about 31mm) to fit.
To open the roof a pole with a hook on it is used to push the upper most roof section first then the lower section. The first time I closed it there was quite a bit of noise with metal coming to rest on metal which would probably disturb the neighbours at 2am in the morning so I added some adhesive weather proof strip along the top edges. It's now very quiet. In fact I think I can open and close it without making a sound. The roof sections are quite light but when opening the leverage can get quite high so I rest the pole against the side and gently lower the section down until the chains take up the slack.
I used some galvanised pipe clamps to hold chains and wouldn't recommend using them as they are too flimsy. You need to use a solid flanged eyelets or some thing else as strong.
Wind gusts will be a problem with the side that is almost vertical so I'll have to find a way to tie it down when open. Probably bungee cords.
You might be wondering why it's located in the corner. Well the rear side is the Adelaide city centre direction (light pollution heaven) and the shed already blocks of the west so the idea is to open up as much of the east and north as possible. I should have at least +/- 45 degrees from vertical in any direction so I can't complain too much. Many people have a lot worse!
You need to watch the pier height as my 10 inch Meade (sct) on an eq6pro mount came within about 10cms of the roof (2m high). The pier is about 1m high.
If you are thinking about an observatory then this might be a reasonably easy and cheapish way to go.
Cheers
Stephen