The Masson Lab 2D clinostat has modular boxes to hold the Petri Plates. Users can select either the clear, vented boxes, or the opaque black/mirrored boxes, depending on the goals of the experiment.
We used an ATmega328 microcomputer to control a 12V 350mA stepper motor connected to a belt and gears. These are connected to a shaft with centrally mounted light-proofed acrylic boxes to hold square Petri plates.
The frame is made of 80/20 and 3D-printed parts and connectors.