Personal Robotic Arm

Overview

This is a personal project to get hands on experience with the full mechatronics stack, mechanical design, fabrication, electronics, and control, in one physical system instead of separate class assignments. I am designing and building a 6 axis robotic arm in Fusion 360, driven by NEMA 17 stepper motors, A4988 drivers, and Arduino Uno controllers. The build is active and ongoing.

Goal and constraints

• End to end scope. Design, fabricate, wire, and program the arm myself, rather than working from a kit.
• Accessible actuation. Use motors and drivers that are affordable and well documented for a 6 axis build.
• Fabrication reality. Design parts that can actually be 3D printed and assembled with the tools available to me.

My contribution

• Designing the arm structure and joints in Fusion 360
• Fabricating custom components on a Bambu P1S FDM 3D printer
• Coordinating multi axis motor control across NEMA 17 steppers and A4988 drivers
• Programming Arduino Uno microcontrollers to drive coordinated axis motion
• Iterating on the design after fit checks and motion testing

Tools and technologies

• Fusion 360
• Arduino Uno
• NEMA 17 Stepper Motors
• A4988 Drivers
• Bambu P1S 3D Printer

Design decisions

• Actuation. NEMA 17 steppers paired with A4988 drivers give straightforward open loop position control across 6 axes.
• Structure. Joints and mounts are designed in Fusion 360 around FDM 3D printing on a Bambu P1S, the fabrication method I actually have access to.
• Control. Arduino Uno firmware coordinates step and direction signals across all 6 axes.

Testing and iteration

• Testing individual axis motion before combining full arm movement
• Checking for mechanical binding, backlash, and alignment issues during assembly
• Revising mounts and joints based on what testing shows

Challenges

Getting consistent, repeatable motion out of 3D printed parts has been harder than the CAD model suggested. Small amounts of backlash and misalignment in the joints show up quickly once multiple axes move together, and tuning stepper current and microstepping has taken real trial and error rather than a single correct setting. Coordinating 6 axes also raises the stakes on cumulative tolerance compared to a simpler arm.

Current status

What I am learning

• What it actually takes to carry a design from CAD to a working physical system
• How mechanical tolerance and backlash show up in real assemblies, not just drawings
• Practical debugging of a coupled mechanical and electrical system across multiple axes