Hi Mike,
Yes, that’s exactly what I’m thinking. Ideally, 18” to 22” diameter rounds – though this is a tougher cut than straight lines. “Lazy Susan” gets masonry screwed to one side then a light coat of mastic strategically brushed on the other “fixing” surface and plop the other marble round on top.
Having all these items on hand, I’ve already checked the rudiments out. Getting a level pedestal (base) is key, since we’re all accustomed to cheating (shimming or foot adjustments) to bring our tables level on off-level bases, stands or what-have-you - in their static positions. But the Lazy Susan mechanism doesn’t produce appreciable error to level in itself.
There’s about a ¼” gap between the marble in which two small rubber wedges can be inserted to secure “stops”. While a drifting, spinning Lenco might be a sight to behold, I’m not sure bringing any Coriolis effect, however slight, into play is a good thing.
Dressing phono cable for payout shouldn’t be too much of a hurdle. Traditional “corner” mounting demands a 90-degree swing for two arms and 180 for three. However, a plinth designed for this application (“thinking outside the box”, Jean once said) could well reduce this to 60/120 degrees depending on the arms and their swing arcs.
The crux question is what you elude to about rattling bearings ... with the huge sink of a Giant Plinth, footed with Acorns + isolators and that atop the first marble round, would vibration still be an issue? If so, what about infusing grease in the "Lazy Susan"?