Thor 6-DOF Robotic Arm

Thor 6-DOF Robotic Arm

A professional-grade, open-source 6-axis robotic arm designed by Ángel Luis Martínez. Thor is fully 3D printable, affordable (€250-350), and suitable for educational projects, research, and maker applications.

Quick Specs

• Type: 6-DOF (Degrees of Freedom) robotic arm
• Height: 625mm (fully extended)
• Payload: 750g (including end effector)
• Motors: 6x NEMA 17 stepper motors (23Nm holding torque)
• Configuration: Yaw-Roll-Roll-Yaw-Roll-Yaw joint arrangement
• Cost: €250-350 (electronics ~€205, mechanical ~€137)
• Build Time: 2-4 weeks
• Skill Level: Intermediate (3D printing + electronics assembly)
• License: CC-BY-SA-4.0 (open source, attribution required)

What's Included

• 49 STL files - all parts ready to 3D print (PETG/PLA)
• 40+ CAD files - FreeCAD sources for customization
• Assembly guides - step-by-step 3D assembly instructions
• Control code - JavaScript interface with home/demo/custom motion functions
• Configuration - 6-axis motor mapping with angle ranges and speeds
• BOM - detailed parts list with sourcing information

Getting Started

1. Review this GitHub repo: https://github.com/AngelLM/Thor
2. Read the official docs: https://thor.angel-lm.com/documentation/
3. Print the parts: Download 49 STL files, slice for 3D printer
4. Source electronics: Arduino Mega 2560 + 6x NEMA 17 steppers + drivers
5. Build the arm: Follow 3D assembly instructions
6. Install firmware: Choose GRBL, RRF, or custom Arduino firmware
7. Use this program: Control Thor with home position, demo motion, and custom sequences

Hardware Requirements

• Arduino Mega 2560 (or compatible microcontroller)
• 6× NEMA 17 stepper motors (23Nm)
• 6× stepper drivers (A4988 or DRV8825)
• 24V/5A power supply
• 6× endstop switches (homing)
• 3D printer (for 49 parts: ~50-100+ hours print time)
• M3/M4/M5 fasteners and threaded inserts
• GT2 pulleys, timing belts, 3D-printed gears

Firmware Options

Thor is firmware-agnostic. Choose one:

• GRBL - CNC standard, simple G-code control (recommended for beginners)
• Repetier Firmware (RRF) - Full 3D printer stack, mature & proven
• Custom Arduino - Direct motor control (educational, more complex)
• Thor-ROS - ROS2 integration for advanced kinematics & Moveit2 planning

Community & Resources

• Official website: http://thor.angel-lm.com/
• GitHub: https://github.com/AngelLM/Thor (all files, CAD, docs)
• Discord: https://discord.com/invite/a5dSVqSUK5
• Forums: http://thor.angel-lm.com/forums/
• BOM & sourcing: https://thor.angel-lm.com/documentation/bom/
• Assembly: Interactive 3D assembly instructions at official docs

Control Software

This program provides basic motion control:

• Home Position - return all motors to safe zero position
• Demo Motion - pre-programmed coordinated arm movement (45° range)
• Custom Motion - define custom angle sequences for your tasks
• Emergency Stop - immediate motor shutdown

For advanced control, see Asgard (https://github.com/AngelLM/Asgard) - the official Thor UI.

Important Notes

• Firmware Integration: Thor requires you to provide your own microcontroller & firmware. This program provides control templates; firmware installation is on you.
• Print Settings: Use PETG (recommended) or PLA with 15-20% infill, 0.2mm layers
• Assembly Sequence: Start with base → joint 1-6 → gripper. Print parts in this order.
• Safety: Always disable power before manual adjustments. Stepper motors are strong — keep hands clear during operation.
• Customization: All designs are open source (CC-BY-SA). Community has created variations, larger variants (XL), and specialized end effectors.

Creator

Ángel Luis Martínez (AngelLM)

• GitHub: https://github.com/AngelLM
• Active maintainer with strong community support
• Used in robotics education & research worldwide

Next Steps

1. Visit https://github.com/AngelLM/Thor to download all files
2. Read the complete BOM at https://thor.angel-lm.com/documentation/bom/
3. Join the Discord community for build questions
4. Use this program to control your built robot

Build Guide

Wiki with full assembly instructions, wiring diagrams, and calibration: github.com/AngelLM/Thor/wiki