The turntable is not very heavy, but I would go to 12mm plywood.
The turntable usually also have an roundhouse where you store locomotives. Several locomotives close together maybe very heavy.
I wouldn't go to foam, but this is just my opinion and others here have more experience in layout buiilding (although I already have a small layout with a turntable).

Hi,

The old turntable 7186 isn't sunken so it stays on the table.



The new one 7286 is sunken.





Cheers

Åke

The C-Track one coming out late 2019 74861 doesn't have the metrics for its dimensions posted yet.

Just that the diameter of the recess is 278 mm, though not if that is the inside diameter or the outside diameter (size of hole you'd need to cut out).
Nothing on the depth of the recess.

Are we still without any information relating the dimensions of the 74861? I don't see them on the maerklin.de page.

Also, the layouts on pages 261-262 of the 2019/2020 general catalogue are completely unuseful. There is a components list but the drawings doesn't show where to place them.

Does anybody have more info?

Regards,

Rafael

Hi

Definitely the TT is not heavy and a 10 mm plywood is good enough. It must be very plane (not warped)
To use foam as a base is not very good for resistance to weight (not the TT weight but the force you apply when you work nearby).
Ideally is plywood the best and a thin foam cover 1 mm thick maximum reduce any noise the mechanism may make in resonance with the wooden frame.
Attention: if there is thin foam it must be on all access tracks and on the TT as well.
The tracks are supposed to be aligned perfectly both horizontally and vertically (no grades)
Cheers
Jean