One of the great successes of desktop 3D printers is custom prosthetics and orthotics. For a fraction of the price of a prosthetic arm, you can buy a machine capable of producing hundreds of completely customizable prosthetics. [Taran Ravindran]’s project in the running for the 2017 Hackaday Prize follows the long tradition of building customized prosthetics. His prosthetic hand designed to be simpler and cheaper than conventional artificial limbs while still giving us some innovation in how this hand will move.
The digits on [Taran]’s hand are controlled by linear servos pulling on a series of Bowden cables. One servo actuates the index finger, with a double differential to close the three less important figures — the middle, ring, and pinky fingers don’t need the articulation of the forefinger and thumb. Those three are actuated together, saving cost and complexity — they basically operate to support the index and thumb rather than being controllable independently. The thumb has 2 DOF by itself to give it the maximum amount of utility.
Another area of importance [Taran]’s focusing on is the matter of ease of use. If the prosthesis is too complicated, difficult, or unpleasant to use, it won’t get used regardless of its awesome features. Knowing this, he focused on making the hand as simplified as possible. Right now, the project has been modeled in CAD, and [Taran] is just waiting for the SLS parts to arrive before assembling the whole thing. It’s a great project, and a great entry for this year’s Hackaday Prize.