TTW MOMENTUS MOMENTUS "The MONSTER" Rim Drive

From how it looks (I'm not familiar with rim drive, more with idlers), the motor drives directly the platter through a rubber O-ring put on it's shaft. I think it's quite a problematic solution: 1) I'm sure they can machine the rim to a great degree of roundness, but it must be matched by the same on the rubber side. I think EMT idlers is a good example here with their machined rubber surface...and even those have roundness problems; 2) The motor is more intimately coupled to the platter than with an idler, which makes it's more visible with all it's cogging.

Also the shaft looks shortish for the 40kg platter, even though it's super hard. Longer shaft=less wobbling (again EMT930/927 is a good example here)

Lewm, looking at the rubber on the motor's shaft it does not look like a precisely machined surface, but I may be wrong. I'm also wondering how they engage/disengage the motor?

Brf, you can think...when you start to listen&measure it can be adifferent experience. I'd not waste my resources on precisely machined copper plate without a mathing rubber surface...and we haven't touched the motor yet

I also suspect the thread/belt drive and idler/rim drive have a different physical optimum of the motor strength/platter inertia, so I doubt one can have a universal solution here, as they propose.