Want to make ice (or other cast substance) in the shape of a sphere? Now you can!Print both halve of the mold, screw them together, fill with water, and freeze. Bearing in mind that ice expands when it freezes (and exerts a surprising amount of force while doing so) I recommend printing with at least three, if not four, perimeters to avoid the possibility of the ice causing delamination in the mold. The mold will print just fine at .3mm layer height, but lower layer heights will produce a finer mold. A note about food safety - Neither ABS nor PLA are considered food safe. I wouldn't recommend using this mold for ice if you print it in either of those plastics. Nylon should be food safe, but there is no consensus about the safety of nylon extruded through consumer hotends. Any printed mold is also likely to contain many small grooves which may provide an environment for mold/fungus/other unpleasant things to grow in over time. Basically what I'm saying is: Make ice in this at your own risk. I'm willing to take that risk myself, but you have to make your own decision on the matter. Customizable variables: top_or_bottom - The same .scad file will produce both halves of the mold, modify this variable to choose which half to produce. wall_thickness - The model is optimized for printing with .42mm thick walls. It should (probably) print with different wall thicknesses, but changing this variable will produce a model optimized for printing at different wall thicknesses. fudge_factor - This variable changes the gap between the connection ball and the connection groove. If the connection is too tight, increase this value. fudge_factor2 - This variable changes the gap between the inner and outer mold halves. You want this to be as small as possible while still allowing the halves to fit in order to prevent the mold from leaking at the joint. mold_size - This variable sets the size of the object to be created in the mold. fineness - This variable changes the number of rendered faces on the round parts of the mold. Increase to make the mold smoother, decrease to reduce the number of faces on the model.