THE TURNTABLE

For the dome to rotate it needs a turntable. I made two sets of rings as before but this time laminated three layers of 12mm ply. I used one layer of structural ply inside two layers of normal ply. I found the normal ply was prone to warping and did effect the resulting rings. Next time I’d only use structural ply and I’ve since found out it uses waterproof glue whereas normal ply uses water soluble glue in the manufacturing process.

I did a rough routing over both rings individually to remove the worst of the imperfections, then layered them on the same cutting platform and cut them together. I was planning to finish the turntable completely before moving on but have since decided to build the wall, which requires the bottom turntable ring, and finish the job on the wall.

The wall was built and the wheels where set into the top ring. I applied paint to everything before fitting the wheels.

Once everything was complete, I found that turning the dome was not as easy as I expected. The wheels should have been rollerblade wheels as they have bearings and taper more than the wheels I used. I also suspect my design allowed the wheels to be pushed outward on the axles and they were rubbing against the wood. Instead of retrofitting new wheels, I had a track bent from 65mmx3mm flat bar mild steel to fit inside the dome ring. I then got some u-groove wheels with bearings and mounted them in angle brackets. I used rollerblade wheels as guide wheels. Once all that was fitted, it got the dome turning with single finger pressure. Total cost there was around $200.

Once I completed dome automation it was clear that guide wheels where not required so I removed them. Final external job was to fit flashing between the rings to keep the water out.