Geared Motor "Servo" Arm

thingiverse

This is an attachment that screws onto yellow plastic DC geared motors commonly used in robotics projects. It can be used to convert rotational motion into linear motion, functioning similarly to servo arms. I uploaded three variants: one with 30mm long arms, one with 15mm long arms, and another with 15mm long arms but a longer shaft that allows you to offset the arm further away from the motor's gear housing.