EPQ Robotic Arm

Overview

Designed and manufactured a complete 6 degree-of-freedom robotic manipulator from scratch as an A-Level Extended Project Qualification (EPQ). The project received the highest grade (A*) and involved four major design iterations progressively refining the mechanical and control systems.

Key Features

• Six independent joints enabling full manipulation capability
• Custom harmonic drive gearboxes achieving approximately 100:1 gear reduction
• Zero backlash operation through strain wave design
• Payload capacity under 0.8kg, suited for light manipulation tasks
• Complete CAD documentation of all design iterations (Mk1-Mk4.2)

Technical Implementation

Mechanical Design

• Custom-designed strain wave gearboxes for high torque density
• 3D printed components (PLA) with recycled aluminium structural elements
• Iterative design process addressing weight and strength constraints

Control System

• Arduino-based motion control with NEMA 17 stepper motors
• A4988 motor drivers with AccelStepper library for smooth motion
• Serial communication enabling remote control via Python scripts

Technologies

• CAD: Autodesk Fusion 360
• Microcontroller: Arduino with C++
• Motor Control: NEMA 17 steppers, A4988 drivers
• Manufacturing: 3D printing, aluminium machining
• Communication: Serial protocols, pySerial

Design Evolution

The project progressed through four major iterations:

1. Mk1: Initial proof of concept
2. Mk2: Refined gearbox design
3. Mk3: Weight optimisation
4. Mk4.2: Final iteration with improved reliability