Talon Hand 2.0 (now 2.7)
by profbink, published
This is a remix of Makerbot's snap pin robohand. Thanks go out to the designers of the "Complete Set of Mechanical Anatomically Driven Fingers", Ivan Owen of Mech Madness Designs http://mechmadnessdesigns.com/ ; Richard Van As of Robohand http://robohand.net/ ; Michael Curry, the designer of the Snap-Together Robohand ; and to all the collaborators at e-NABLE https://www.facebook.com/enableorganization
I've optimized the design to be more ergonomic/comfortable, and to use leather as an interface material. With 3 pieces of leather you can mount this prosthetic device to a person lacking fingers on one hand.
Two sets of fingers are included: One with snap pins and one for Chicago screws.
Here's a clip of my son Peregrine putting on his Talon 2.2:
And here's he is playing at home:
After upgrading to 2.7, and some 2.0mm monofilament cables:
For more information or to get involved, visit http://enablingthefuture.org/
Now available here is a wide unipalm and matching wide cable guide. Thanks for the great mod, Ivan Owen!
***Significant upgrade on Feb 5, 2015!! Please provide feedback on the new files, and contact me if you need old files. There is now a cable anchor that takes 10 set screws, two for each cable, to prevent cable slipping, and the cable guide now has a left and right version, and better guides the cables, so that monofilament can push as well as pull, therefore obviating the use of elastics. :D
You can print everything but the finger distals with no support.
Ivan Owen has published an excellent step-by-step tutorial, in 3 parts:
Thank you Ivan!!
I'm working on detailed written instructions for all my wrist-powered devices at:
The cable anchor for the Talon Hand uses set screws. I used round trimmer line (like for landscaping) for the cables, and found that in a small print, if I mount the anchor forward and close to the cable guide, the hand will open without elastics. The cables push and pull. If your hand is not opening satisfactorily, you can install elastics. But if possible, avoid elastics, since they make it more difficult to close the hand.
Here is the hardware list for a build at the scale of 1, a good size for a 4-5 year old child.
wrist hinge: (2) 8-32 x 5/8" flat head hex screw; (2) 8-32 nylock nut
Anchor mount: (3) 3m x .5 x 8mm flat socket cap screw; (3) 3m x .5 cap nut
Cable anchor (5) set screws 6-32 x 1/4
Cable guide: (4) truss head sheet metal screws #4 x 5/8
Palm leather tacks: (16-20) truss head sheet metal screws #4 x 3/8
Leather to arm bars: (8) 6-32 x 3/8" flat socket cap screw
- a layer of 1" nylon webbing: (1) 6-32 x 7/16" flat socket cap screw
- 2 layers of 1" nylon webbing: (1) 6-32 x 1/2" flat socket cap screw
3 pieces, each ~a foot long 0.05" round trimmer line (landscaping type) for the cables. Fingertip ends of the line are melted into balls with a lighter so that they catch in the tips.
I typically build this for Peregrine, my adult son, at a scale of 1.6. He has an extra-large right hand. Obviously, the hardware should be larger for his build. Here's a list of hardware:
Talon Hand/Ody Hand at scale of 1.6:
10 Arm Bar Screws #10/24 x 3/8 or slightly shorter flat socket cap screw
2 Wrist Hinge 1/4" x 3/4" and nylock nuts
20 Palm Tacks #6 x 1/2
5 Set Screws
4 Cable Guide Screws
Cable anchor 3 flat socket cap screws and dome/acorn nuts
Nylon or Poly webbing for strap(s) and/or palm reinforcement.
You should have three pieces of leather: One very thick, for the one med
You can make a closure with Velcro or double D-rings. OdyBars are for a child's device and uses a single strap on the third hole. There is a space so the strap is comfortable between the plastic and leather. ArmBars are for an adult's device and use two straps. Loop the straps in holes 1 and 3.
If you print small, the spaces between the parts will be smaller, so more finishing is usually needed. If you print the device small (100-130%) use PPsnap4small instead of ProxPhalSnap (better for 140-160%)
Now there is a zip file containing Ivan Owen's wide palm Talon Hand. Thanks again Ivan!