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
Working in a team of two, we 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.
