This is a mold for quickly making snowballs in the shape of a rhombic dodecahedron.

This particular polyhedron has a couple of properties that make it really cool for snowballs:

• It's space-filling, meaning that you can stack these with no gaps in between
• All opposing sides are parallel, so you can easily grip the snowball using the mold itself for throwing, and also easily unmold it with a sliding motion parallel to one of the faces.
• Its 2D projection from a corner looks exactly like a cube projected from a corner, so photos of these look like impossible cubes from the right angles.

I've included pre-made STLs in Small (good for quick snowballs to throw), Medium, and Large (good for sculptures), but you can copy and tweak the original design to your heart's content in OnShape.

Print instructions

The models are oriented so that the 45 degree bottom infill is parallel to one pair of sides of the bottom face for a more uniform look, so leave the rotation as is in your slicer.

They print great with no supports.

The pictures are of:

• The Small printed with 0.2mm layers in Prusament Neon Green PETG
• The Large printed with 0.3mm layers in Sunlu Orange PETG

PETG seems to work well to easily release the snowball from the mold, but PLA should work just fine too.