Yes I worked on 8 Versions of A coaster. Used A learning Model to get to grips with 3D modelling in Fusion 360

Designed for Standard mugs to slot in the centre but slightly larger than needed so other sized mugs can fit too.

I did try to use A halo design with no central material but it would allow smaller mugs or glasses to fit.

I also put walls on it to catch drips and rings on the bottom to make taking it off your printer easier.