Knick's finger, v2.0

thingiverse

For the latest design, check out http://www.thingiverse.com/thing:904304. This is version 2 of my prosthetic finger designs, suitable for individuals missing the last 2 segments of a finger, who still have a short stump. I can provide Sketchup files or export in another format if helpful. Here it is in motion: https://www.youtube.com/watch?v=iSYBMSrvFLY. I want to thank those great folks who've been working on 3D printed prosthetics longer than me for their inspiration and ideas. If you need help with finger prosthetics, please contact me. Instructions To print the socket, use NinjaFlex. Then, use PLA for the parts. The PLA cleanup is standard; ensure all holes are smooth and hinges fit cleanly with enough clearance. In the next revision, I'll refine some of the tolerances a bit. I print everything with support; you might be able to get by without it on some parts. For the socket, a quick pass inside with a Dremel sanding drum clears out that area well. For hinge pins, use PLA with caps on the ends for a clean look and positive closure. Just cut some filament a bit longer than needed, melt the end briefly with a lighter/soldering iron, and squish the cap onto the end. Same elastic as most hand projects use; however, I prefer 50lb braided fishing line for the tendon. It needs to anchor on the other side of your wrist so that bending the wrist doesn't move the finger, only moving the stump does. To do this, I use a bracelet where the tendon anchors back to. Then, connect the tendon to an aluminum turnbuckle from an RC car using small jewelry clasps (cheap on Amazon). These clasps allow for easy adjustments of tension. I like how the turnbuckles work and look but they're pricey, so in another revision, I'll come up with something printable for that part too.