For anyone who wants to build an observatory like mine, I have discovered a fault in the design that I shall attempt to rectify very soon. It involves the rollers that the dome pivots on. The setup I have works well in theory, but requires a lot of fiddling to get right, and then may still not be satisfactory.
I have come up with a new rolling design consisting of a rolled flat bar of 50 x 5 mm mild steel, to the diameter of the dome, running on pulley wheels only, that support AND guide. This will negate the need for support casters and extra horizontal guide wheels.
I have corrected it on my website with a bitmap concept diagram which I hope will clarify.
Cheers,
Barry
Barry's home made observatory
http://members.iinet.net.au/~armstead