Screwless (Almost) Robotic Anthropomorphic Hand
19 May 2018 - I downloaded a gearModule.scad script from somewhere in OpenSCAD forums and placed 4 gears together.
20 May 2018 - first prototype, sketch5_3 is done
21 May 2018 - sketch5_6, with limits
22 May 2018 - sketch5_7, flex-back
26 May 2018 - sketch6_1, _2
12 September 2018 - better metacarpal bones
14 September 2018 - metacarpal body sketch6_0v2, 4 finger prototype
Nondestructive - this means that during assembly I do not glue, thread, break, melt anything. The whole hand can be later on disassembled and reassembled without breaking a thing. Servos can be unmodified, even the servo horn is not attached using a screw.
The whole design is made using source code-oriented tools, this simplifies sharing and modification of each element. Also, version control and comments.
Difference between this and Pisa IIT Softhand
More prominent gears for support, more wires for the Hillberry rolling joint. More 3D printer-friendly, as parts are generally designed to be printed without supports or with minimal amount.
The hand with servos is easier to replicate, but the flexibility and freedom of design suffers greatly. Despite that, the prototype is working and properly actuated.
PowerHD HD-1800A (SG90 should work too with changed mounting dimensions)
Ideas storage for later:
First stage - no bearings
Quite a bit of friction, but the hand seems controllable.
Second stage - for control wire routing only
MR52 - 2x5x2 1.50$ per 10 aliexpress MR62 - 2x6x2 1.50$ per 10 aliexpress
Whatever is mine (so without gearModule.scad) is licensed under CC-BY-4.0 - enjoy!