Exploradome sells a kit for dome rotation. I thought a different design might be fun to try.

But first, you need wheels. I wanted a urethane type, with a 1/4" or 5/16" hole for the axle, and ball bearings if I could find them.

After some digging, Sport's Shops sell repair kits for inline skates and offer a variety of wheel sizes and types.

An 80mm wheel comes out to 3 1/8: and should be what I needed.

Here is a pix of what I got.

I thought you might like the pretty printing. Others were much better but cost more. Note the two ballbearings that are included. Very smooth, they are.

About 7/8" thick which was great.

And, 8 of them are $40. $5 each. I bought 16 total and there will be a wheel every 22 1/2 degrees. Wanna save a bit more? Buy them on the internet. "Dick's" were the cheapest. BUt I wanted to see and feel and measure.

Btw, a 1/4" bolt/shaft fits perfectly in the 8mm hole of the bearing.

Here are the current thoughts of how the ring will look in cross section.

Turquoise - Top ring attached to the dome
Yellow - Middle ring that holds the wheels.
Salmon - Bottom ring attached to the walls of the Asylum.

The wheel is pink. An approximate location of each corner of the octagonal walls is in red (Corner Post) and an approx location of the walls themselves is in green. Being octagonal, the wall between the posts will measure less than to the post.

I am going to build the posts and walls before I finalize these measurements.

But, doing things this way, a number of issues go away and benefits arise.

The dome will be alot more round than using the plastic rings etc.

This arrangement should operate much more smoothly than the Mfgr' method.

It might be cheaper than buying the mfgr's version.

I will have more wheels to distribute the weight. I hope this allows the dome to be pushed from one place to the other very easily.

A problem I am facing will be to keep the ring segments, after being glued together, round and concentric, one to another. Especially, the groove where the wheels will ride on both the upper and lower irings..