National Institute of Technology Agartala, India · B.Tech Project · Mechanical Design · Robotics · Servo Control

Design, Fabrication and Analysis of a Three-Finger Gripper Actuated by Micro Servos

Affiliation: National Institute of Technology Agartala, India

This undergraduate project focused on developing a three-finger robotic gripper using micro-servo actuation/control, fully in-house fabricated mechanical components, and experimental evaluation of grasping behavior.

Mechanical designIn-house fabricationServo actuation/controlTesting

Project overview

The project explored the design of a compact three-finger gripper for robotic grasping applications. The work combined link design, in-house mechanical fabrication, hardware integration, servo actuation, and benchtop testing to create a working prototype.

Every mechanical part of the prototype was fabricated in-house, including the aluminum finger links, drilled and bored servo mounting features, the MS bar, threaded rod, handmade nut, support frame, and gripper assembly. The system was developed as a full gripper rather than only a single finger mechanism, with attention to mechanical construction, grasping layout, and the relationship between applied load and sensor output during testing.

My contribution

Contributed to the design and in-house fabrication of the complete three-finger gripper mechanism.
Fabricated or supported fabrication of the mechanical components in-house, including aluminum links, drilled servo mounts, threaded rod, handmade nut, MS bar support, and the suspended test setup.
Integrated micro servos, structural links, custom fasteners, and the gripper frame into the final working assembly for servo-actuated controller integration and validation.
Participated in prototype evaluation and load-response measurements.
Helped develop and refine the final working prototype shown in the project images.

Objectives

Design a lightweight three-finger gripper using micro-servo actuation.
Fabricate the mechanical parts in-house instead of relying on an off-the-shelf gripper platform.
Build a working prototype and integrate the complete finger assembly.
Evaluate basic grasping performance and mechanical behavior.
Measure response under different loading conditions.

Results

Built a functional prototype of a three-finger servo-actuated gripper with in-house fabricated mechanical hardware.
Demonstrated complete assembly with custom-made links, handmade threaded components, suspended support structure, and actuation hardware.
Collected load-response measurements across different test weights.
Established a practical foundation in mechanism design, assembly, and experimental validation.

Tools and methods

In-house fabricationMechanical fabricationHand threadingDrilling/boringServo motorsServo controlCustom fastenersPrototype assemblyExperimental testingLoad evaluation

Technical focus

Robotic end-effectorIn-house fabricationServo actuation/controlMechanism designHardware assemblyLoad testingLabVIEWNI ELVISArduinoPrototype validation

Selected figures

Threaded shaft and hex nut used in the gripper mechanism

In-house fabricated hardware. Hand-threaded shaft and handmade mating nut used in the custom gripper mechanism.

Collage of the gripper prototype and suspended test setup

In-house fabricated prototype assembly. Multiple views of the servo-actuated three-finger gripper, including custom links, frame, fasteners, and suspended support structure.

Load-response measurements. Voltage response plots recorded across test loads from 0 g to 35 g.

Final prototype image of the three-finger gripper

Working prototype. Final in-house fabricated gripper assembly used as the project cover on the main portfolio page.

View project report · View COPEN 2019 paper / oral presentation