Home
This work is licensed under the Creative Commons Attribution 4.0 International License. For more information see the bottom of the page.
El Medallo is the world's cheapest-to-fabricate open source bionic prosthetic. Created at eNABLE Medellin now called Humanos3D, the mechanical design of the device is a variant of the Kwawu Arm (by Jacquin Buchanan). You can see the story of its creation on youtube.
Our design features 2 different grips, a pinch grip and a power grip, each activated by EMG sensor signals from 2 unique muscle contractions. These 2 unique grips are achieved by altering the timing of 2 servo motors controlling the fingers.
Construction of this prosthetic appears complicated at first, however we provide a step-by-step guide here and anyone with basic electronics and 3D printing experience can make this themselves. The estimated fabrication time from start to finish is approximately 80 hours. If you are creating a custom fit insert, add another 10 hours; this will be longer if you are unfamiliar with fusion 360. This estimate includes file preparation, sourcing parts, soldering circuitry, calibrating the EMG sensors with the patient and assembly. This time may be longer if you need to alter this prosthetic for a particular patient or if the prosthetic does not fit in the first attempt (this can happen).
Before starting please read each of the articles below to understand the full process of fabricating this bionic arm.
Disclaimer: This prosthetic is still being developed and the prosthetic and documentation is subject to change. We do not recommend this prosthetic for recipients who can receive and use a mechanical prosthesis such as an unmodified Kwawu Arm. The final fitting of this prosthetic and patient training should be completed by an individual with experience in medical prosthetics.
- Preparation
- Manufacture
- Assembly
- User Guide
- Technical Documentation
(This documentation is not required reading for fabrication of the arm)
- Development Findings for Wider Enable Community
- Replacing Components
- Modifying the Cad Design
- For eNABLE Groups interested in the continued development of the El Medallo, please contact us for access to our private repositories.
People who helped bring this project to life, in no particular order:
- Mark Walbran: Electronics and Programming, Project Management
- Mohith Mothukuri: Socket Design, Electronics
- Oliver Vogel-Reed: Kwawu Arm Modifications, System Integration
- Brynmor Davis: Sensor Research and Development of EMG Patient Protocol
- Ben Complin: EMG Calibration Protocol and Algorithm Debugging
- Esteban Rojas: CAD work, 3D Printing Wizard
- Adam Armfield: Director of eNABLE Medellin
- Vincent Nguyen: Socket Design
- Elena Guss Tarazona: CAD Work and Assembly
- Natasha Pentin: Administration
This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.
In simple language you can:
- Share — copy and redistribute the material in any medium or format.
- Adapt — remix, transform, and build upon the material for any purpose, even commercially.
Under the following terms:
- Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
See the links below for more information on development: