The build docs, PCB notes and software date from 2020, with high-level control mostly in Matlab, and the authors have moved on to PAROL6.
Faze4 is a 6-axis desktop arm by PCrnjak of Source Robotics styled after small industrial arms. Every joint uses a 3D-printed cycloidal gearbox driven by a stepper motor, and all wiring runs inside the printed shell. It weighs around 15 kg and has roughly 1,000 parts including screws and bearings.
At a glance
| Parts cost | $1,000–$1,500 (2020) project · The project docs say around $1,000 to $1,500, while the README says under $1,000 source ↗ |
|---|---|
| Difficulty | 4/5 Advanced · Around 1,000 parts, large slow prints, hand-assembled cycloidal gearboxes and a custom PCB with known errors in its first version. |
| Build time | Not stated |
| Tools needed | 3D printer with at least a 250x210x200 mm bed (197 printed parts, PETG recommended), crimping and wiring of 6 external stepper drivers, optional PCB fabrication for the distribution board |
| Motors | 6 steppers (3 Nema 23, 2 Nema 17, 1 Nema 14 with 19:1 gearbox) driving 3D-printed cycloidal reducers and HTD belts |
| Controller | Teensy 3.5 on a custom distribution PCB, with external TB6600-style stepper drivers and a 24V supply |
| Sensors | Micro and roller limit switches plus 2 inductive sensors for homing |
| Published | ✓ Parts list✓ CAD/STL✓ Assembly guide✓ Wiring✓ Software✗ Video GitHub (assembly PDF, parts list xlsx without prices, electronics setup PDF, STL zip, URDF) + Read the Docs site |
| Activity | Last update 2025-12-28 · 903 GitHub stars · Discord, 152 forks, Hackaday.io page |
| Kits | No Faze4 kit found. Source Robotics now sells kits of its later PAROL6 arm instead. |
Licenses
| Design files | CERN-OHL-S-2.0 (LICENSE file replaced the earlier one in September 2025) source ↗ |
|---|---|
| Code | CERN-OHL-S-2.0 per the repo LICENSE file (README still shows an MIT badge and says 'Project is under MIT Licence') source ↗ |
| Documentation | No separate docs license; README states MIT, LICENSE file is CERN-OHL-S-2.0 source ↗ |
Builder notes
Practical points from the project's issue tracker, forum and docs, each linked to its source.
- The design and docs have barely changed since 2020. Recent commits only touched the README and LICENSE, and the same team's later PAROL6 arm is where active development went. source ↗
- The README and LICENSE disagree. The README badge and footer say MIT, while the LICENSE file was swapped to CERN-OHL-S-2.0 in September 2025, so anyone redistributing a modified design should follow the stricter reciprocal terms. source ↗
- Only STL meshes are published for the structure (STEP files exist only for the cycloid discs). A 2021 request for editable CAD to fit cheaper 18 mm inductive sensors got no answer, so changing parts means editing meshes. source ↗
- The parts list lists 50x67x7 bearings but the manual uses 50x65x7, a mismatch builders spotted. source ↗
- The docs warn that the first distribution PCB has many errors and some drivers must be wired differently from the plan. A second board revision was added later. source ↗
Other arms plans
- MeArm · $40 · difficulty 1/5
- SO-101 arm · $230 · difficulty 2/5
- EEZYbotARM MK2 · $100 (2018) · difficulty 2/5
- GELLO teleoperation arms · $280 (2023) · difficulty 2/5
- Thor arm · $390 · difficulty 4/5
- reBot-DevArm (Seeed Studio) · $1,500 · difficulty 4/5
- OpenArm · $6,500 · difficulty 5/5
- Koch v1.1 arm · $480 (2024) · difficulty 2/5
- ROBOTIS OpenMANIPULATOR-X · $1,600 · difficulty 2/5
- BCN3D Moveo · $430 · difficulty 4/5
- PAROL6 · $970 · difficulty 4/5