Simple mod to permanently stack and stabilize these IRIS small parts organization bins. The feet act as templates to drill the holes that hold the stack together in the middle. They are attached with some of my favorite fasteners, R-Type Nylon Rivets. (If you haven't tried them, you should. No captive nuts, or fancy CAD geometry required.)

Fully printed on one X1C bed, attached to 2 sets of these and seems to work pretty well.

Rivet sizes are "R 4070" and "R 4120" for the Body and Feet Respectively.

12 of each needed for the middle section and feet per stack.

Amazon Link To Bins

Aliexpress Link To Nylon Rivets