Geared Motor "Servo" Arm

thingiverse

This is an arm that you can screw on to the yellow plastic DC geared motor assemblies usually found in robotics projects. It can be used to convert rotational motion to linear motion much like how servo arms work. I uploaded 3 variants - one with 30 mm long arms, one with 15 mm long arms, one with 15 mm long arms but with a longer shaft so you can offset the arm further away from the gear housing of the motor.