The best way is to use V grooved wheels on an inverted right-angled aluminium
track.

My roll-off roof observatory is 12' X 8' and has five 4" wheels each side. It is
easy to roll off by hand and stays on the track perfectly. The roof is very
substantial too.

I got my V grooved wheels from McMaster-Carr in the US - I couldn't find a
source in the UK.

Do a search on Google for "Roll-off roof observatories". It will turn up a huge
number of resources including plans for the roll-off roof itself which is what I
used. Why re-invent the wheel!!

Good luck - a permanent observatory really is the way to go.

Nigel

"Martin Taylor" wrote in message
...
Ok, I am going to build a run-off shed and need an idea as to how to make
the slide-off roof slide off, without being flimsey or too cumbrous to move.
Is there any one here who has made one and can give me some tips, on what to
do/ what not to do?

I looked in the first edn. of Moore's book on observatories, but that does
not tell you HOW to make a run off roof, run off. It has plenty of images
of people's observatories, but little on the technique behind their
construction, and it that which I need!

Any help would be greatly appreciated!

Martin T