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open source

Design data of HACKberry are avaialable on github.
(3D model, PCB sketch, arduino code etc.)

3D-printable Open-source Bionic Arm

 HACKberry is the 3D-printable open-source bionic arm project founded by exiii Inc. in 2015 along with Mission ARM Japan, a Tokyo based non-profit organization hosting a grassroots community for people with upper-limb disabilities. 


  • Size: 225 x 150 x 60 (mm)

  • Weight: 450-500g

  • Sensor:  pressure sensor (photo reflector)

Download data from github


 Data of HACKberry are available on github.

 Here you can download  3D CAD data, arduino codes, circuit diagram as well as BOM (i.e. bill of materials).

Your participation to share skills and wisdoms is very appreciated!



Don't know how to make robots? No worries!

There are some ways to learn how to make HACKberry.


What are goals and challenges?

"Casual choice" is the concept of HACKberry.

Commercial bionic arms have been expensive and restricted in choices.  HACKberry takes a unique approach to overcome these problems. Instead of providing a final uniformed product, HACKberry shares the recipe to make such product. In other words, it open-sources all the design data online. In this way, users can save expenses and it opens room for developers to customize and add features to such arm easily.


  However, many challenges remain to make HACKberry useful in the daily lives of people with various symptoms of upper limb disabilities.

 Regarding the prosthetic hand itself, it is still difficult to reproduce the skillful functions of a live hand given the current level of science and technology, so we need to build a function step by step based on the voice of actual users. Socket, the part that connect a prosthesis to a residual limb, also needs improvement. Since the shape and size of arm vary widely, the socket has to be tailor fit. In particular, better socket is waited for users who have lost the limb above elbow, and users who has wrist and some fingers remained.


We hope these challenges can be solved by the HACKberry open source community.

About exiii Inc. 

 exiii Inc. is a hardware startup established in 2014.

Genta Kondo was the first CEO, and led the development of 3D-printed bionic arm handiii, handiii COYOTE and HACKberry.


About Mission ARM Japan

 Mission ARM Japan is a non-profit organization established in 2014 by cancer patients who lost their upper limbs to support peer support. Genta joined the organization in 2015 as an engineer member to promote HACKberry, and moreover, to initiate other projects that may solve challenges of upper limb disabilities together with actual patients and various creators.

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