3D Printed Prosthetic Hand Helps Out For About $150

February 8, 2013 by Mike Szczys 26 Comments

3d-printed-prosthetic-hand-on-thingiverse

We know that there are already 3D printed hips and knees in use in the medical field, but it takes a story like this one to really bring home the idea of how this technology changes lives. 5-year-old [Liam] is missing parts of his right hand, and this open-source prosthetic hand has given him a jolt of increased function. The video clip after the break shows him on the third day with the device. He’s practicing picking up coins from a stack using the hand. Just $150 in parts, combined with the hard work and good nature of the developers, made this possible.

The design is available on Thingiverse. In addition to the 3D printed parts the prosthesis uses off-the-shelf hardware store items like bungee cord and fasteners. The tips of each finger and the thumb are given some flex and grip by covering each with a rubber thimble.

We love seeing this life-changing technology wielded by basement and garage hackers. Another great example is this scratch-built leg from last May.

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A Constant Resistance Dummy Load Design

February 8, 2013 by Mike Szczys 21 Comments

constant-resistance-dummy-load

This constant resistance dummy load has not yet been tested in the real world. [YS] was inspired to come up with the circuit after reading Wednesday’s Re:load dummy load post. That was a constant current load, not a constant resistance load. [YS] started with the schematic for the Re:load and made his changes to arrive at this.

For him the exercise was just to alter the design to achieve constant resistance. He didn’t actually build and test the hardware because he doesn’t really have a need for it. This image was exported from Proteus, which includes a ProSPICE circuit emulator. His slides run through test voltages from 5V to 50V, maintaining a constant 10 Ohm resistance.

When studying this project we needed a little refresher on the different varieties of dummy loads. We found this post very informative about the differences and uses of Constant Current, Constant Power, and Constant Resistance (Impedance) loads.