Construction Detail - Page 3

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The wheels are v-groove and 4" in diameter. They are rated at 800 lbs. The wheels ride on roller bearings and can be greased. This picture is for size reference. VWT Inc. made the wheel cages and mounting plate assembly.
Next came the frame for the roll-off-roof. I took extra care when I mounted the rails to make sure they were parallel for the entire 20 ft section. 3 wheels on each side gave the needed support to prevent sagging. Wheels are mounted to 4 x 4 posts 10 ft long. As mentioned earlier, each end of the rails has a fabricated stop to prevent the roof from "really rolling off". This is a close-up view of one stop.
Roof framing is complete. I raised the roof an additional 2 ft to clear the scope when it is in the parked position. This also gives plenty of headroom inside the observatory. A look on the inside to show the 2 ft section and the roof support detail. Extra care taken here to ensure a very rigid structure that will remain square so it will roll easily and seal the weather out.
Another view with the roof in the "off" position. Plywood installed and black felt down. It's beginning to look like an observatory. My faithful Basset Hound always checks out the daily progress.
It works !! I'm thinking that this project will actually get finished before it turns cold. I find myself chanting in a strange accent - "roof on, roof off" This gives you a good idea why I oriented the roof to roll off to the East. Between the house, trees, and light pollution, I really can't see anything until they clear the trees anyway, and that is still about 45 degrees below the meridian.
Here is a close-up of the wheels and rails. I have had to make some minor shimming adjustments as the wood finds it final resting point, but everything still works as advertised. Shingles are now installed and I have closed in the east end. Since the walls are only 5', you must remember to duck when you go through the door. Two or three knots on my head later, it became a natural motion.

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