These are free, open-source designs from the e-NABLE community. You don't need to pick one to make a request: your volunteer will help you choose.
It mostly depends on which joint can do the work. e-NABLE hands and arms are body-powered: bending the wrist or elbow pulls cords that close the fingers.
For missing fingers when most of the palm is there.
Bending the wrist closes the fingers; straightening it opens them.
e-NABLE Phoenix Hand v3 · Phoenix v2 Hand · Kinetic Hand · Osprey Hand · Unlimbited Phoenix Hand
See all hand designsFor a missing hand or forearm, below the elbow.
Bending the elbow closes the hand. Also a good fit when the wrist can't bend or the palm is missing.
Unlimbited Arm v2.1 · Gripper-Kwawu (long forearm) · Gripper-Kwawu (short forearm)
See all arm designse-NABLE designs for above-elbow limb differences are still a work in progress.
The NIOP modular system may be a fit. These organizations also do excellent work for above-elbow amputees:
See above-elbow designsMissing part of a finger, or need help with one activity like cycling, music, or eating?
There are mechanical fingers, plus simple tools such as bike handle adapters, guitar pick holders, and utensil cuffs.
Still not sure? That's fine: leave it to your volunteer, or ask the friendly designers on the e-NABLE Community Forum.
People missing some or all fingers who have most of their palm and a wrist that can bend at least 30 degrees. Bending the wrist closes the fingers of the device.
Good: The currently recommended design. Snap pins are labeled for easier assembly.
Watch out: The plastic mesh palm has to be heat-formed into a curve. As with the Phoenix v2, the palm-to-gauntlet angle should be 30–35°.
Assembly tips: Probably the easiest design for beginners to print and assemble. Simple, high-profile elastic bands straighten the fingers; watch that loose finger joints don't trap the elastic and stop the fingers returning.
Good: A solid design. Printed at about 120%, it suits a large child or small adult.
Watch out: The whippletree is a little more complex.
Assembly tips: Keep the palm-to-gauntlet angle at 30–35° while stringing and tensioning; balancing the angle and three strings takes some practice at first.
Good: A beautiful design modeled on real human anatomy, with extensive, high-quality documentation for preparing, printing, and assembling.
Watch out: Needs flexible filament, which not every printer handles. The flexible hinges work less well at larger sizes (heavier fingers), and the flexible palm and tensioners reduce grip efficiency.
Assembly tips: The flexible parts are the tricky bit: a direct-drive extruder helps a lot when printing them, and the hinges can be hard to insert into the finger slots.
Good: Strong plastic Bowden cables replace separate tendons and straighteners. The most fluid action of all the designs.
Watch out: The leather gauntlet and palm add cost and complexity.
Assembly tips: Ten small set screws add complexity, and the instructions don't say exactly how far to tighten and tension them, so expect some trial and error.
Good: A solid design; three tensioners make assembly easier. Smooth action, similar to the Osprey.
Watch out: The plastic mesh palm has to be heat-formed into a curve, and the palm-to-gauntlet angle should be 30–35°.
Assembly tips: One of the easiest designs for beginners. Watch that loose finger joints don't trap the elastic bands.
Good: Very small at 100% scale, so good for small children.
Watch out: Elastic and line share the same palm holes, and the small size makes assembly harder.
Assembly tips: At 100%, only thin elastic fits the palm holes, which limits how strongly the fingers return. Five fingers to tension individually.
Good: Popular, especially with children. Printed finger bumps help grip without needing grip tips.
Watch out: Uses Chicago bolts, and each of the five fingers has to be tensioned separately.
Assembly tips: The Chicago bolts stick out, especially at the gauntlet strap, and can get in the way of the outer two tensioners. Tensioning five fingers individually is fiddly.
Good: An appealing, natural-looking design. Flexible hinges replace separate elastic tendons.
Watch out: Finger return is weak, particularly at larger sizes, and grip strength is low.
Assembly tips: The flexible hinges are hard to fit into the fingers and may need trimming. Even at 100% infill they return weakly at larger sizes. Five fingers to tension individually, and the gauntlet's high arch makes thermoforming tricky.
Good: A sleek, natural-looking hand with easy finger action. Fingers are printed with built-in joints, so no extra pins are needed.
Watch out: Pins and the gauntlet-to-palm fit are loose, and the finger hinge supports on the palm are thin and fragile.
Assembly tips: Printing the large palm and gauntlet upright can cause problems. Small palm holes limit you to lightweight elastic, and the fragile hinges limit grip strength. Further engineering is needed.
People whose arm ends at the wrist or below the elbow and who can bend the elbow easily. Bending the elbow closes the hand of the device.
Good: A good design with straightforward hand assembly and tensioning (the same hand as the Unlimbited version).
Watch out: Thermoforming the forearm makes assembly harder.
Assembly tips: The forearm is formed in two directions (round for the arm, and rotated 90° for the hand), which can take several attempts. The end of the forearm also needs to be pressed in with heat so the strings reach the palm smoothly.
Good: A beautiful, natural-looking arm. The socket version has an adaptable grip and a rotating hand.
Watch out: Large adult sizes must be printed in segments and welded or glued. The flexible hinges struggle to return the fingers at large sizes, and stringing two whippletrees is complex.
Assembly tips: Probably the hardest design to assemble: small blind holes in the fingertips are difficult to string, and parts may need shaving to move smoothly. Not recommended above 100% hand size.
People missing part of one or more fingers who would like a mechanical finger that moves with the remaining joint.
People whose arm ends above the elbow. e-NABLE designs for this are a work in progress (e.g. NIOP modules, Shelbow), so these requests are best suited to experienced volunteers.
People who need help with a particular activity, such as holding handlebars, a guitar pick, or utensils, or who need a gripping aid or another assistive device.
Good: Very simple: only two parts. The grip is very strong thanks to a strong elastic band as the thumb tensor.
Watch out: The large hand needs supports and is hard to print cleanly. The cable ties must be strong but have small enough buckles to sit in the palm recess.
Assembly tips: A good device for someone with one fully working arm, who can open and close the thumb by hand.
Volunteer notes come from hands-on reviews by e-NABLE volunteers. Made one of these? Share your feedback about a design.
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