Rack And Pinion Parallel Grabber

This is a simple, compact rack-and-pinion parallel grabber designed as a fully 3D-printed assembly and powered by a single DC BO motor. The design focuses on minimal parts, ease of assembly, and reliable parallel motion. Two opposing racks slide smoothly inside the printed body, while a centrally mounted pinion gear drives both racks at the same time, ensuring equal jaw movement. The pinion is directly connected to the BO motor mounted at the rear, eliminating the need for complex linkages or additional motors. This makes the grabber lightweight, cost-effective, and easy to maintain. It is well suited for small robotic arms, educational projects, and general-purpose gripping tasks where simplicity and efficiency are important.
 

Assembly:

1. Slide the two 3D-printed racks into the side slots of the grabber body, with the teeth facing inward.
2. Place the pinion gear in the center so it meshes with both racks.
3. Press the gear into position; the rear hole aligns it and supports the gear shaft.
4. Mount the DC BO motor at the back of the body.
5. Connect the motor shaft directly to the pinion gear, which also helps keep the gear from coming out.

When the motor rotates, both racks move equally to open and close the jaws. Since a BO motor is not self-locking, apply constant motor force while gripping to keep the object securely held. You can also use a 12v stepper motor.