The technical staff at Jaco Products, plastic injection molders of PPS, loves a good challenge and this project was no exception. The PPS 40% glass-filled part is used as a shaft for tachometers and end coders. The part required a ± 0.0002″ tolerance, not only on the id and od through the length of the part, but also on the spacing of the fingers and flange. When injection molding the fingers, they would move out of alignment when cooled- presenting quite the challenge for any skilled plastic injection molders.
With Jaco’s depth of experience across many plastics disciplines including injection molding, machining, and plastic stamping, we developed a multi-process solution to mold the part to near net shape using the CNC machine to the ± 0.0002″ tolerance. Using innovative plastic injection molds and a proprietary fixturing design, the exact required space tolerance of ± 0.0002″ on the fingers was achieved.