Mechanical files, electronics and firmware sit in different organizations' repos, there is no written assembly guide, and nothing has been updated since 2024.
A tendon-driven humanoid hand and forearm by Rob Knight of The Robot Studio, printed entirely in plastic with 16 slim micro-servos in the forearm pulling the fingers. A wrist with optional continuous rotation is included. IoT Design Shop later added electronics on an Arduino Nano RP2040 Connect, firmware, a ROS 2 layer and a build wiki.
At a glance
| Parts cost | $300 (2023) project · Stated by the project in 2023 source ↗ |
|---|---|
| Difficulty | 4/5 Advanced · Dense tendon routing through a printed forearm, parts needing drilling and sanding, and docs spread over two organizations. |
| Build time | Not stated |
| Tools needed | 3D printer (large forearm prints; PLA, PETG or CF nylon, 0.6 mm nozzle recommended), fine sandpaper or diamond files, 2 mm drill, soldering for the electronics build |
| Motors | 16 Emax ES33xx slim micro-servos for fingers, 2 Feetech SCS2332 wrist servos, optional SCS15 for wrist rotation |
| Controller | Arduino Nano RP2040 Connect (IoT Design Shop electronics) with BLE or USB serial |
| Sensors | None beyond servo control (unconfirmed) |
| Published | ✓ Parts list✓ CAD/STL✓ Assembly guide✓ Wiring✓ Software✓ Video GitHub README parts list + public Onshape CAD + YouTube assembly playlist + IoT Design Shop build wiki |
| Activity | Last update 2024-07-26 · 577 GitHub stars · 101 forks on the original repo; IoT Design Shop repos have smaller followings |
| Kits | None found |
Licenses
The design license is non-commercial. Building one for personal, educational or research use is allowed, but selling builds, parts or kits is not.
| Design files | CC BY-NC-SA 4.0 source ↗ |
|---|---|
| Code | CC BY-NC-SA 4.0 (dexhand-ble firmware repo LICENSE) source ↗ |
| Documentation | CC BY-NC-SA 4.0 (dexhand.org) source ↗ |
Builder notes
Practical points from the project's issue tracker, forum and docs, each linked to its source.
- Mechanical files and the parts list live in The Robot Studio repo, while electronics, firmware, ROS 2 and some durability tweaks live in IoT Design Shop repos. The project site recommends following the IoT Design Shop electronics build. source ↗
- There is no written step-by-step guide in the original repo. The most complete reference is Rob Knight's YouTube assembly playlist for V1. source ↗
- A tendon port in the forearm interferes with the servo mounting tail and is meant to be cleared with a 2 mm drill before assembly. source ↗
- The forearm shells intentionally leave a gap so cosmetic covers can clip on, which confused builders matching the Bulk and Split prints. source ↗
- A cheaper SG90 servo version was promised but only a single-finger example was released. source ↗
Other hands plans
- LEAP Hand · $1,800 (2023) · difficulty 2/5
- AmazingHand · $140 · difficulty 2/5
- UMI gripper (Universal Manipulation Interface) · $370 (2024) · difficulty 2/5
- RUKA hand · $1,300 · difficulty 3/5
- Aero Hand Open · $320 · difficulty 3/5
- ORCA Hand · $2,000 · difficulty 4/5
- YUBI glove and gripper (Toyota) · $550–$750 · difficulty 4/5
- Yale OpenHand (Model T42 / Model O) · $1,400 · difficulty 3/5