Several months ago I received a commission to create a functional prosthetic hand based off of the Phantom Pain hand used in Metal Gear Solid 5. This was for a client who was born without a left hand and grew tired of his standard claw style prosthetic, but didn't want to shell out thousands of dollars for a motorized medical grade prosthetic. The goal was to create something durable, functional and useful on a budget. This is what I came up with. My client has very little left of his wrist, meaning the standard active grip system on other 3D printed prosthetics wouldn't work for him, so I designed a passive grip system using retention springs. This allows the fingers to (more or less) auto-adjust to whatever object they are gripping, and only requires user input to actually open the grip, which is done by pulling the knob at the rear of the forearm section. All 5 fingers normally open and close at once, but there is also a detachable ring connected to the main knob which articulates just the index finger, which can be locked in place to allow greater usability in actions such as typing and pressing buttons.
I'm releasing these files for free because I want them to get into the hands of other people who actually need a prosthetic and can use them to better their lives. The total material cost for the final device is under $100. Here is a breakdown of the additional parts you will need:
Order these;
14x Low profile 4-40 Locknuts: https://www.mcmaster.com/#catalog/122/3213/=15s86hk
50x 4-40 7/8" screws: https://www.mcmaster.com/#catalog/122/3018/=15s87ym
20X 4-40 5/8" screws; https://www.mcmaster.com/#catalog/122/3018/=15s89ba
14x Tensions springs (option to use stronger springs here for increased grip strength); https://www.mcmaster.com/#catalog/122/1283/=15s89og
10 feet of 1.2mm stainless steel braided cable; https://www.amazon.com/gp/product/B00GYTWM4I/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
Normal hardware store stuff;
1x 6-32 Locknut
2x 6-32 40mm screws
2x 6-32 15mm screws
12x 13mm rubber grip pads
7 10mm rubber strip grip pads
Super Glue (for holding the pads in place)
Epoxy putty (For filling the connection between the cables to the pull knob)
Preferred type of foam for internal padding (high density open-cell foam recommended)
I'll have a lot more info about this build and an instruction manual about how best to assemble the parts in a few days time. I'll also be posting all the original CAD files and encourage more experience designers to modify them in anyway they like, be it for a slightly different look, enhanced grip, individual finger control, etc etc. Lets collectively make this as widespread and useful as possible, very much looking forward to seeing what people do with these files!
Printer:
Flash Forge Creator Pro
Rafts:
No
Supports:
Yes
Resolution:
.200 microns for most parts
Infill:
40%
