The door

This is made from the remainder of the second large ring. Only this time, the arcs need to be cut in half lengthwise. It is made much the same way as the frame, with some added braces in between, (I used 2). All you need to do then is skin it using a piece of plywood, or you can find a way to attach the bits you cut out of the dome for the slot hole. I used liquid-nails under all the screwed surfaces to make the door rigid and sturdy. I want this thing to last! On the back of the dome I mounted two parallel aluminum rails for the door to slide back on. This was quite a task!  When I got it finished, it worked ok, but I think it could be better. I also think it could LOOK better, so I think next weekend I may pull them off and try to do a more professional job. This thing does have to last and look good! To make the slide action a little smoother I screwed in some rollers on the inside edge of the door. A wood stopper goes on the inside bottom of the door to provide a stop for down and up positions. This stops the door from sliding all the way off. At the top of the door I installed a weather flap made of strong flexible plastic gutter guard.

Ok. I did what I intended and fixed up the rails on the back. I bought a second pair of aluminium rails and riveted them together. I then built brackets out of sturdy, but still bendable steel. Instead of using screws to secure everything, I used bolts this time. I think it will be stronger. I changed the positions of the rollers inside the door a couple of times until it slid  better. To stop the door from rolling off all the way when open, I bolted a couple of stirrups to the bottom of the rails. To stop the wind from blowing the door off while open, I bent a couple of brackets up to bolt onto the rail supports.

The door has proved to be a challenge on several attempts to get it to roll freely and easily without sticking, jamming or binding. I have since done away with the original design and am now looking at roller shutter designs or I may eventually have to go for a slide sideways door. One option was an accordion style, (picture below) but it doesn't look like it is going to be the answer. More on this later so stay tuned....

I have designed a slide sideways door using some aluminium window track, attached to top and bottom of the slot and parallel. The door will attach to the track via rollers. Hopefully this will slide easily, be easy to secure and be weather-proof.. If you look at my diagram, I intend to make the right side of the door as you look at the picture, overhang down on the left, and the right hand side will be flat, but run up on to a rubber seal so the rain cannot get under it.

Ok. Heres the next step in improving the rolling action if you still want a classic, roll over the top door. I am going to run two 10mm diameter steel rods down the sides of the door, and one down the middle back of the dome. This will form a track for a three-point rolling system. On the tracks will roll two rollers, top and bottom of each rod. I have turned down some rollers from a nylon material. I will keep you posted as this develops.

Here's the completed roller assembly, made from an off cut of RHS, a couple of bolts, washers and spacers. It will attach to the underside of the door.  The slot cut in the side allows the assembly to pass freely over the brackets that will attach the guide rail to the side of the slot.

And here's the new door. I purchased a length of 50mm x 50mm x 6mm thick angle aluminium and had it rolled to a 1.5 metre radius. It was then cut in half and spaced evenly apart to cover the slot, rails and allow for some overhang as well.  It was then skinned with aluminium sheet and riveted in place and painted. I bolted the roller assemblies to the inside of the bent sides at the front, and on the back of the door.

Getting the thing to roll smoothly was just a matter of patient tinkering and adjusting to get it right until I was happy with it. It's not an exact science, but try to get it as smooth as you can.