Overview
Injection molding inverts the usual design problem: you don't design the part, you design the negative of the part — plus everything the process demands. The mold for this whistle had to account for draft angles on every vertical face, a parting line that wouldn't scar functional surfaces, and dimensional compensation for polymer shrinkage so the as-molded whistle actually plays.
Execution
I modeled the cavity and core from the part geometry with shrink factors applied, planned toolpaths for 3-axis milling within GD&T tolerances, and machined the mold halves. The result is a production-style tool: loaded into a press, it produces a complete working whistle.
