Split roof observatory

[alistairsam]

hi

Its been a while in the making, i've started with a split roof observatory in my backyard.

i had a few design goals, I wanted a roll off roof but did not want the permanent tracks with supports as it requires the same area as the obs to be blocked out. I don't have space in the sides. so a split roof made sense as I would just need to figure out how to suspend half the roof at each side

I wanted it to be low profile as this is just outside the kitchen window and I did not want to block the view of the backyard from inside the house.
so decided to build it to a height that just clears my scope when parked horizontal. that provides the lowest profile.

stay on budget, I did not want to spend too much as i'm renting and wanted it to be modular to dismantle and re-assemble elsewhere.

no requirement for me to stay within the obs, so ended up with the size 2.4 x 2.1m which was bigger than i thought but allows enough room for me to walk around the scope when imaging.

some pics. will explain the roof in the next post.

Alistair

[alistairsam]

For the roof supports, I thought of various methods to support an extended roof without vertical supports, finally ended up with this design that works by positioning wheel tracks at the appropriate points such that when the beam that supports the roof extends out, it starts off being supported on two bottom castors, but as the COG crosses the outer wheel, the wheel on top takes the load and is supported by the upper track.

I had to offset the two halves vertically as the roof needs to roll off 1.2m, but the beam needs to be longer than that to act as a cantilever.
the offset design allows the use of a 1.8m beam, and the roof will be made with lightweight materials including insulation. each of the castors are rated at 50kg each. I expect the whole half roof to be less than 50kg.

for tracks, I initially thought of the sliding gate track but thought i'd make my own. so routed out a V and a straight, glued an aluminium flat for the wheel to roll on and avoid compressing the timber when the roof is left at one position for a long time.
its not the smoothest, but will do the job as I'm not planning on motorizing it.

As for waterproofing the split, I will add on an overhang on one half so it completely covers the split. the two halves are also sloped slightly to prevent water collecting.
I went with blue cement sheets for the sides.
the sides and the roof will be insulated.
Corners will also have a channel with some render to make it water proof.

Thinking of 6mm marine ply for the roof as its not taking any load and should be light enough.
will be using pine where possible for the roof frame, hardwood at support points.

some pics.

test video of one of the beams
https://youtu.be/JjvHbOsIo7E

[alistairsam]

some pics

[bojan]

Interesting solution for wheels, I like it :-)

[Hemi]

I think the kitchen drawer type roof design is brilliant, not seen that being done before for an observatory roof.

Cheers

Hemi

[mynameiscd]

Hi Alistairsam,
I've got something similar on my beach block. Never fully finished but its got a similar roof design.
I've only got some older photos with my old gear and before the pier
Had a few minor leak issues early on but have fix the centre flashing.
Its made of foam wall panel I had left over from a couple of jobs. Its got a R2 rating so it doesn't heat up during the day.
Made a simple lightweight rondo steel frame and screwed the panels on.
No rollers, just C Channel guides it slides on.
I like it because you can adjust the gap either way to a slit so in winter you stay quite warm.
With foam you could quite easily make it modular and dismantle it.
No real need to render but I did because i'll never move it.
I've rendered it with acrylic render and my wife had done some arty decorations.
You can also get roofing panel with colorbond iron already attached.
Good luck with the build.
Cheers
Andy

[alistairsam]

Thanks for the pics Andy, that's a lot simpler than mine.

[alistairsam]

Almost done with the build.

Added Styrofoam insulation, polycarb heat reducing roofing, and a gutter in the middle for water to flow to the sides.
still need to add insulation to the walls and seal the corners, but had first light tonight.

video of a soak test. passed with no leaks.
https://youtu.be/oYGAg8QjEHI

Regds
Alistair

[alistairsam]

few more pics

[Andy01]

Very Impressive Al! :thumbsup:
Looking forward to seeing some new images from the setup :)

[SimmoW]

Brilliant Al! Loving all these pics and details from everyone, will really help when we finally do our sheds. The most challenging part seems to be the roof mechanism and ensuring it doesnt blow off in high winds.

[bojan]

Yes.. Low profile is the answer.
When I was asking around for someone to do the lid for me, the requirement for 6000N test pressure was mentioned...
Never keep the entrance door open when windy - otherwise the roof could be lifted and blown away if not secured in both directions.

[TrevorW]

Wondering roughly how much did it end up costing you to build ;)