Three-Finger Synchronous Gripper with Gear-Driven Full-Cover Protection Shield

I. Design Inspiration

Building on the gear‑rack‑driven three‑finger gripper, we’ve added an integrated, sealed gear protection cover to address issues such as dust ingress and tooth jamming caused by exposed gears. A single servo motor drives all three fingers in synchronized, ring‑like grasping motions, providing both transmission protection and enhanced gripping stability. This design is well suited for simple workshop robotic arms or DIY outdoor picking robots.

II. 3D Printing Process

The gripper base, finger claws, and protective housing are printed using PLA, while the gear rack is made from PETG to enhance wear resistance. A 0.3 mm clearance is left between meshing teeth, and a 0.1 mm assembly allowance is provided for hinge holes. The protective cover is integrally molded without requiring secondary assembly, featuring no overhanging thin walls and only minimal support at the claw tips, making printing and post‑processing straightforward.

III. Structure and Function

The enclosed protective cover fully encases the gear‑rack transmission pair, effectively preventing dust, impacts, and foreign‑object jams. With a single drive source, the three fingers can synchronously converge toward a central axis, while the curved claw surfaces securely grip spherical or cylindrical objects without slipping. The cover also includes built-in screw mounting holes for easy disassembly and maintenance, and its rear-mounted standard mounting bracket allows direct attachment to robotic arms.