The control board design and the editable CAD are not open source.
PAROL6 is a 3D-printed 6-axis desktop arm from Source Robotics, built to resemble industrial arms in its mechanics and control software. It uses Nema 17 steppers with planetary gearboxes and belts, and comes with a desktop GUI, a Python API and ROS 2 simulation. The STLs and software are published, but the control board is a closed design sold by the company.
At a glance
| Parts cost | $970 estimated How Estimated for this page from current retail prices (2026-10-02) of the parts in the project parts list source ↗ Build priced Main build from the parts list with the pneumatic MHZ2-16D gripper and the official control board bought with drivers fitted; vacuum gripper and small-print-bed parts left out Not included 3D printing, tools, shipping, tax; laptop; air compressor or air supply for the pneumatic gripper |
|---|---|
| Difficulty | 4/5 Advanced · Many printed parts, gearboxes and belts, homing and calibration that trips up builders, and mains power wiring. |
| Build time | Not stated |
| Tools needed | 3D printer (PETG recommended; small-bed variant files provided), crimping and wiring, mains-voltage power supply wiring (project warns of lethal voltages) |
| Motors | 6 Nema 17 steppers, several with 20:1 or 10:1 planetary gearboxes |
| Controller | Proprietary PAROL6 control board bought from Source Robotics, with TMC5160 drivers, 24V supply |
| Sensors | Limit switches and an inductive sensor for homing (per issue #13) |
| Published | ✓ Parts list✓ CAD/STL✓ Assembly guide✓ Wiring✓ Software✓ Video GitHub (parts list markdown, building instructions PDF, STL) + docs website + YouTube tutorial playlist + forum + Discord |
| Activity | Last update 2026-10-02 · 3,335 GitHub stars · Discord, Discourse forum, 397 forks |
| Kits | Source Robotics sells the full arm, kits and the control board |
Licenses
| Design files | GPL-3.0 for STL files only; STEP CAD sold separately and not open; control board PCB not open source source ↗ |
|---|---|
| Code | GPL-3.0 source ↗ |
| Documentation | GPL-3.0 (docs site says code, building instructions/parts list and STL files are GPLv3) source ↗ |
Builder notes
Practical points from the project's issue tracker, forum and docs, each linked to its source.
- The control board is not open source. A DIY build still requires buying the board from Source Robotics, and builders hit this when it was out of stock. source ↗
- Only STL files are published under GPLv3. The editable STEP files are sold separately and the company says they should not be shared, so modifying the design means editing meshes. source ↗
- Builders report dead parts list links, especially for the pneumatic gripper, and AliExpress links that only allow ordering one unit. source ↗
- The building instructions show the J4 output pulley in two different orientations on different pages, which caused confusion. source ↗
- Homing problems after assembly usually come from steppers spinning the wrong way, fixed in code or by swapping motor phases. source ↗
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