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SolidWorks 3D Printing FEA Mechanism Design CATIA V5

Robotic Arm End-Effector — Design & Manufacture

Design, FEA validation, and manufacture of a 3-fingered adaptive gripper end-effector for a 6-DOF industrial robot arm, capable of handling objects from 20–120 mm in diameter.

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Robotic Arm End-Effector — Design & Manufacture screenshot

Overview

This project involved the full design-to-manufacture cycle of a 3-fingered adaptive gripper for integration with a Universal Robots UR5e collaborative robot arm. The gripper needed to reliably handle a wide range of cylindrical and prismatic objects without requiring gripper changes between tasks.

Design Requirements

Requirement Target Spec
Gripping range (diameter) 20 – 120 mm
Max gripping force 80 N per finger
Mass ≤ 600 g (inc. actuation)
Material PLA+ (prototype), 6061 (production)
Actuation Single servo motor (underactuated)
IP rating IP54 (dust & splash proof)

Design Process

Concept Generation

Generated 5 concept designs using morphological charts, evaluated against requirements via a Pugh matrix. The underactuated linkage concept was selected for its simplicity and adaptability without requiring individual finger actuators.

Kinematic Design — SolidWorks

Designed the 4-bar linkage mechanism for each finger using SolidWorks Motion Study:

  • Modelled full finger closure from 0° to 90°
  • Optimised link lengths to maximise gripping force transmission ratio
  • Ensured no singularities through full working range

Structural FEA — ANSYS Mechanical

Validated all structural components under worst-case loads:

  • Load case: 80 N grip force + 15 N inertial load (max robot acceleration)
  • Minimum safety factor: 2.0 on all load-bearing links
  • Critical part: Proximal phalanx — peak von Mises stress 42 MPa (yield: 55 MPa for PLA+)

Manufacture & Testing

  1. Prototyping: FDM 3D-printed in PLA+ on a 0.2 mm layer height, 40% gyroid infill
  2. Fasteners: M3 stainless steel screws + press-fit brass inserts
  3. Actuation: MG996R servo with custom aluminium crank arm

Test Results

  • Successfully gripped and transferred cylinders from Ø22 mm to Ø118 mm
  • Consistent grip force within ±5 N across full object size range
  • No structural failures over 500 open/close cycles
  • Mass achieved: 542 g (within spec)

Manufacturing Drawings

Full GD&T production drawings were produced for all machined components, including tolerance analysis for the critical linkage pin fits (H7/g6 clearance fit).

Future Work

  • Redesign in 6061-T6 aluminium for production use
  • Add force sensing via strain gauges in the fingertips
  • Integrate ROS2 control node for autonomous grasping