Radial-Cage Robotic Gripper

Degree Objective 3

Develop mechanical control systems by implementing transducers, actuators, feedback, vision and sensing systems, and other mechanical systems into robotic platforms.

How it meets the objective: It develops a complete mechanical control system — one linear actuator, chosen from real vendor specs, drives eight cage arms in coordination through a sixteen-bar linkage, with the motion validated in CAD.

An original soft-enclosure end effector designed in Fusion 360: eight curved cage arms with TPU contact balls close around fragile objects, driven by a single linear actuator through a sixteen-bar linkage.

Built in RBT205 (Final Project) with Fusion 360 CAD and motion study, around the igus drylin DLE-LA-0003 linear actuator.

How it works

A NEMA17 stepper linear actuator drives a sliding collar along the central axis. The collar's vertical travel rotates sixteen linkage arms, which sweep the eight cage arms inward around a fixed hinge ring — thereby enclosing the object rather than pinching it. Load is distributed across many soft contact points, making the design suited to fruit, packaged goods, and other delicate or irregular items.

Engineering highlights

Original mechanism: the concept was developed from scratch — inspired by arcade claw and scalp-massager form factors — not adapted from a reference design.

Real actuator specification: the igus DLE-LA-0003 was selected against published specs — 100 N axial force, 0.075 mm feed per 1.8° step, dryspin lead screw.

Honest motion analysis: the Fusion motion study uses a slider joint to validate linkage behavior before modeling screw kinematics. The study exposed a linkage interference, now documented with a refinement plan covering bearings, clearances, guide stiffness, and prototype testing.