Directional Freezing Clear Ice Sphere Mold

This is a model for a three piece ice sphere mold designed to fit inside a standard Thermos to use directional freezing to form clear ice spheres. You may need to play around with water amounts and freezing times to get good spheres. I printed all three pieces in PLA. Printing the top piece in something flexible, such as TPU, would likely be a good idea for easier removal.

If you're worried about food safety, coat the pieces in food-safe epoxy or polyurethane and let cure.