ThorRR

ThorRR is a fork of the open-source Thor robotic arm, redesigned around RepRapFirmware with modified parts, optical endstops, and an updated BOM.

The original Thor mentioned RepRapFirmware support, but in practice the RRF configuration was incomplete, undocumented, and not usable out of the box. ThorRR fixes that and makes several other changes:

Firmware & Electronics

• Fully working, tested RepRapFirmware configuration
• Replaces the Arduino Mega + GRBL setup with a single RRF-compatible board (BigTreeTech Octopus Pro v1.0)
• Newly designed control application called Bifrost

Modified Parts

• Optical endstop improvements
• Redesigned base
• Several parts resized for better fit and printability
• Several sections reinforced to prevent deformation after heavy use
• Reduction in required cooling fans
• Improved cable path

Updated BOM

• Some components differ from the original Thor bill of materials to accommodate the above changes

• Open Source: Built on open source software — FreeCAD, KiCAD, RepRapFirmware, and ROS.
• CC-BY-SA-4.0 Licensed: All source files published under the same license as the original Thor.
• Low Cost: Hardware cost below 350€.
• Suitable for Education: Perfect for robotics courses in schools and universities.
• Tested RRF Configuration: A working RepRapFirmware setup, not just listed as supported.
• ROS2 Integration: Available implementation using Docker for flexibility.

• freecad-src – Source files of 3D models created with FreeCAD
• fusion-src – Source files of 3D models created with Fusion 360
• mods – Modified models and improvements to standard models
• stl – Printable STL files
• step – STEP files

• Thor (original): The original Thor project by AngelLM that this fork is based on.
• Bifrost: Control application designed for ThorRR.
• Thor-ROS: ROS2 & Moveit2 configuration files and packages to work with Thor.
• ThorControlPCB: Source & manufacture files of Arduino Mega shield designed for the original Thor.
• Asgard: Control software for Thor motors with a simple interface (original Thor).

1. Read the Documentation: Comprehensive guides on printing, assembly, electronics, and firmware are available at thor.angel-lm.com/documentation.
2. Print the Parts: Use the STL files in this repository.
3. Get the Hardware: Take a look at the Bill of Materials. Note that ThorRR has some BOM differences — see above.
4. Assemble the Robot: See here for assembly videos and interactive instructions.
5. Assemble & Setup the Electronics: The Wiring & Setup guide covers the general approach. ThorRR uses a BigTreeTech Octopus Pro v1.0 instead of the Arduino Mega shield.
6. Install the Firmware: ThorRR uses RepRapFirmware. The original Thor firmware docs are here for reference.
7. Control the Robot: Use Bifrost to control the robot.

• Degrees of Freedom: 6 (yaw-roll-roll-yaw-roll-yaw)
• Height Stretched: 625mm (without end effector)
• Payload Capacity: 750g max (including end effector weight)
• Motors: Stepper motors
• Electronics: BigTreeTech Octopus Pro v1.0 (RepRapFirmware)
• Transmission: 3D printed gears, GT2 pulleys and belts
• Software: FreeCAD, Fusion 360, KiCAD, RepRapFirmware, ROS2

• thor.angel-lm.com — Official website for the original Thor project
• FAQ
• Thor Forums
• Thor Discord Server

Contributions are welcome! If you'd like to improve ThorRR — whether it's design, documentation, or code — feel free to open an Issue or submit a Pull Request.

ThorRR is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License, the same license as the original Thor project. You're free to use, modify, and distribute this project under its terms.