3D Printed Servo Gripper

This mechanism converts the rotational motion of a servo motor into a clamping motion using a gear-driven four-bar linkage system. Designed for hobby robotics, pick & place tasks and students.
 

1. Gear Specifications

Standard: Spur Gear
Pressure Angle: 20°

Module: 1.25M
Teeth: 18T
Pitch Diameter: 22.5 mm

2. Theoretical Calculations
 

A. The horizontal distance between the two gear centers

B. Position Analysis (Four-Bar Linkage)

C. Recommendation: Limit the servo rotation to the specific range of 120° to 35°. 
 

Why: To prevent mechanical interference between the components

• 120°: Fully Open position.

• 35°: Fully Closed (Grip) position.

3. Hardware

Joint Assembly Method For simplicity, the joints use a Screw and Double-Nut (Jam Nut) setup. The nuts lock against each other to maintain clearance for movement. 

Alternative: Pins or Shoulder Screws.

4. Assembly & Design Videos