Open Bionics Modular Prosthetic Terminal Device System

At Open Bionics, we are excited to share our modular wrist system designed for developing and interchanging prosthetic terminal devices.  The system supports quick disconnect wrists like the popular USMC-style that is used by our Hero Flex activity arm.

This is an industry-first initiative that aligns with our mission to make prosthetics more accessible, affordable, and adaptable for all.  

By releasing these designs under a Creative Commons - Attribution - Noncommercial - Share Alike license, we aim to empower the global community to innovate and create their own solutions for prosthetic devices.

These building blocks are available here on the Printables platform, with detailed assemblies also available in OnShape, providing an open-source foundation for users to design and customise prosthetic terminal devices. Whether you're an engineer, maker, or prosthetist, this system is a springboard to share your designs and inspire others.

As certain designs gain popularity, we may engage their creators to explore opportunities for formal testing and manufacturing under a royalty-based license. We believe that collaboration and open design will help drive the future of prosthetic technology.

Join us in this open-source initiative to enhance the possibilities for prosthetic limb development!

A little inspiration…

Using the included DIY / Lego attachment, you could try building anything from a pen holder to a pea shooter.  Or design a new attachment entire from scratch, how about:

• A weight training tool
• A pool cue holder or rest
• A ball thrower
• A guitar pick holder 
   

Printing Guidelines

We make extensive use of Prusa 3D printers for in-house prototyping and production.  These designs have all been printed and tested on Prusa MK3S, MK4 and XL in PLA and PETG.  

Recommended profile: 0.15mm STRUCTURAL

Fasteners

The collar system is designed to printed in two symmetric halves, in one of three sizes, then secured together using 2x N4x5/8" (16mm) Pan Head Self Tapping screws - either Torx or Pozi.  Example source: https://www.accu.co.uk/pozi-ab-self-tapping-pan-screws/163921-SPPT-No-4-5-8-A2-BL

Quick disconnect wrist inserts (e.g. USMC-style) are connected with a ½" UNC bolt.  Insert + bolt kits will soon be available on our web shop.

OnShape Design Document

Please use this link to access the OnShape design files: https://cad.onshape.com/documents/e725d463a647572c8235d96c/w/3a778fabbf716125cad7cd27/e/d00bb2a6731bd24076527288

The OnShape document contains:

• Overview
• Collar interface
• Printable USMC insert
• Modular wrist system including 3x sizes of collars
• Example terminal device assembly

For more information on the Hero Flex activity arm: https://openbionics.com/en/heroflex/

Liability Disclaimer

By downloading the provided 3D printing data, the user acknowledges and agrees that it will be used solely in accordance with the specified printing parameters and assumes all associated risks. Open Bionics disclaims any and all liability for personal injury, property damage, or any other harm that may result from the use or misuse of the provided data. The user accepts full responsibility for any consequences arising from its use.