I used a similar gear-like feeder from Make Anything before, but i was not quite pleased with the design because it would always come off and was not that nice to turn, so i made one on my own.
The part is pushed onto the extruder stepper motor to be able to turn the motor and push filament through the extruder or load filament. So there are two tasks the part needs to fulfill which require different speeds of turning. That's why I made this small round part on top with wish the motor can be turned quite fast. The two arms or wings below are used to turn the motor slowly.
Supports are required like shown on the picture and i used 2 perimeters and about 15 % of infill.