As part of my curriculum at Cal Poly, I took a tooling and fixture design class. In this class, I designed an ergonomic pocket-sized screwdriver. To manufacture this screwdriver design, I designed an injection mold and machined it using a HAAS VF-2 CNC mill. After machining the mold, I set it up on a small injection molding machine and created three screwdrivers. For this lab, I did the entire process from designing the screwdriver and mold, creating the toolpaths for machining the mold, operating and machining the mold, and injecting the screwdriver handles.

For the screwdriver design, I employed good injection molding design practices, such a uniform wall thickness, symmetrical design, and more. My handle also has fillets on all sides to ensure it releases from the mold easily.

For the design of the injection mold, I created a two-piece mold with a parting line going right through the middle of the screwdriver handle. For this mold, I designed and sized the sprue, sprue well, and runner to properly work with the injection molding machine and the nylon plastic we have in our lab. In addition, I designed holes for dowel pins to help with aligning the two mold halves together. I also designed work holding tabs for toe clamps to allow the mold to be clamped and installed on the injection molding machine. For my mold, I also ensured all edges were chamfered to ensure no one would get cut or injured installing the mold.