Mechanical Gripper—Dual Servos—Double the Force

I. Design Inspiration

To address the insufficient gripping force of single-servo grippers, this design employs two SG90 servos driving a pair of linked gears to open and close synchronously, delivering twice the clamping force. Specifically engineered for small robotic arms and robotics competitions, it meets the grasping requirements of STEM projects while also serving as an educational demonstration tool for mechanical transmission principles.

II. 3D Printing Process

The main frame and gripper are printed using PLA filament, while the gears can optionally be made from PETG for enhanced wear resistance. A 0.3 mm clearance is left at the gear meshing points, with wall thickness set at 2 mm. The design avoids large overhangs, adding support only to the small curved surfaces at the claw tips, and is compatible with standard screw assembly.

III. Structure and Performance

The dual servos are symmetrically arranged, driving the gripper’s opening and closing action through two sets of interlocking gears, doubling the torque output and enhancing gripping strength. The rear end features standard mounting holes for direct attachment to the robot arm’s end effector, while the non-slip surface on the gripper jaws improves grasping stability.