HACKberry
BGuides and BOM only — orobot firmware does not yet support this hardware.
Sign up to ExploreAbout this program
HACKberry is a 3D-printable, open-source myoelectric (EMG-sensed) bionic hand created by exiii Inc. (Tokyo) and the Mission ARM Japan community. A forearm-mounted photo-reflector sensor detects muscle flexion; an Arduino Micro reads the signal and drives three servo motors (thumb, index finger, and a linked "other three fingers" group) to open, close, and lock a grip — enough for daily tasks like holding a cup or pinching small objects.
The project ships full mechanical CAD (STL + STEP), custom PCB sources (KiCad/Eagle) for the hand board, sensor board, and battery board, and working Arduino firmware (three sketch variants: v3.0, Mk2 v1.0, and a v3.1 Mk2 EMG variant).
Source: https://github.com/mission-arm/HACKberry
License — dual license, read carefully before building or distributing:
- Arduino firmware: GNU GPL v3.
- 3D data, hand/sensor/battery PCB data: Creative Commons BY-NC-SA 4.0 (non-commercial use only).
- Commercial use of any part requires written permission from exiii Inc. (contact: info@exiii.jp). Do not sell assembled units or derivative commercial products without their sign-off.
Photos: official HACKberry site (exiii-hackberry.com), © Exiii Inc., CC BY-NC-SA.
🖨 Print Files (15)
R-H-01.stl
R-H-02.stl
R-H-09.stl
R-I-01.stl
R-I-06.stl
R-O-01.stl
Required Hardware
Commodity / Buyable Parts (electronics & hardware)
| Part | Description | Qty | Source |
|---|---|---|---|
| Arduino Micro | Main microcontroller (ATmega32U4) | 1 | Adafruit |
| DMW-BLF19 | Li-ion battery + charger | 1 | Amazon |
| ES08MD (Emax) | Small servo motor (index + other-finger actuation) | 2 | Emax |
| HD3001HB | Large servo motor (thumb actuation) | 1 | rcMart |
| QRE1113GR | Photo-reflector muscle-flex sensor | 1 | Mouser |
| DC/DC Converter (1.25–35V/3A) | Adjustable power converter | 1 | Seeed Studio |
| Resettable Fuses (RXEF050, RXEF040) | Overcurrent protection | 2 + 1 | Mouser |
| Steel balls, springs, screws, bearings | Mechanism hardware (coil/tension/torsion springs, M2/M3 screws, shafts, bearing) | assorted | Lee Spring / Sotec / Hirosugi-Keiki / wilco / Amazon |
| Mini stereo audio cable + jack | Sensor-to-hand signal cable | 1 | Amazon |
| Velcro strap | Sensor-arm strap | 1 | Amazon |
| PCBs (BatteryBoard, HandBoard Mk1/Mk2, SensorBoard) | Custom circuit boards — KiCad/Eagle source files included in repo, fab via any PCB house (e.g. OSH Park, JLCPCB) | 3 boards | n/a (source files in repo) |
3D-Printed Parts (from HACKberry_3Dmodel/STL/)
109 STL files total, organized by assembly group (mirrored Left/Right sets):