Dome Rotation - Suggestions

I am almost finished building my dome observatory, but I am having a little problem with rotating the dome (which is why one choses a dome in the first place ). I am currently using a steel rail with steel V-groove casters (photo attached). The problem with this is that there is a tendency to derail the casters from the ring. I wonder if rollers would be more forgiving. Robert Hayes' rollers/ball casters look interesting. Appreciate your help.
Paul WB

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Paul, have you verified that the circle is true? Have you deburred the edge of your "track" and tried applying some grease? These are what i would do first.

I would loose the rail and change the rollers to skate wheels. Modify the horizontal wheel to keep the dome aligned by running on the plywood rotation ring and you will loose a lot of head ache. I have been involved in doing both ways and have found the steel rail to not provide anything to the system but problems. Besides the with the horizontal wheel the V groove is superfluous.
Magic Man
SSMO

Hi Paul,
I see you noticed my transfer bearing idea. I don't know how well it will work, I'm still working on the building.
I had six 1/8" steel arcs water jet cut to place on top of the walls for the bearings to roll on. The inside diameter of the steel hangs over the inside wall top plate by 1/2". I did this because I'm using garage door rollers mounted to the dome ring to locate the dome in the xy axis. The rollers roll on the inside diameter of the top sill and the steel overhang will keep the dome from possibly blowing off.
I'm siding the building now and should have pics soon.
Bob