Box Holder For scaled-down Catan Pieces. The outside dimensions are 40mm long, 40mm wide and 20mm tall.
The inside dimensions (the hollow section) are 32mm long, 32mm wide and 14mm deep. Therefore the wall thicknesses should each be 4mm.
This object was made in Tinkercad. Edit it online https://www.tinkercad.com/things/dhnUWpXADu3
dhnUWpXADu3.stl | 1.4KB |