You might have heard about the 3D-printed prosthetic hands created by Richard Van As and Ivan Owen for about 100 children thus far. That's a great thing they've been doing. There's also a "Snap-Together Robohand" version, http://www.thingiverse.com/thing:92937
, which is intended to be easier to build. I'm sure it is... but it still takes half a day to print the parts and assemble them. Unfortunately, I had less than 3 hours total on Saturday, September 28, 2013, to give an overview of making technologies and have YMCA Black Achievers
students actually build something. So, I designed a new prosthetic/robotic hand for which all the printed parts print assembled without supports in less than an hour. You still have to thread some fishing line and rubber bands through it, but from print start to working hand is easily done in less than 90 minutes!
The hand is roughly sized to match that of a 18 month old girl. It embodies a variety of compromises, any of which might make it unusable as a prosthetic in practice... but it certainly is functional enough to get the idea across -- which was my goal. I know very little about prosthetics, but I do know that fitting them is a very personal thing, so the primary design doesn't have a mount attached. It is possible to add a simple mount and still have the complete structure print assembled as either a prosthetic hand or a hand for a robot.