I have designed a unique rotary block and tackle system to allow very small stepper motors to drive finger joints with resistive force and high precision
Each knuckle on each finger is designed to fit FSRs for sensing intended motion, and uses a through-hole potentiometer to encode current position
Motion is driven using UHMW (ultra-high molecular weight) fishing line threaded through narrow-gauge medical tubing
All parts are modeled in Fusion 360 and printed with PLA on my QIDITECH 2
Parts have been designed to be easily machine-printable with minimal supports and no glue so that full disassembly for maintenance is possible
The leads on the FSRs are soldered very carefully and wrapped in shrink tubing to prevent analog noise from motion
The joint system is designed to fit around the sides of the knuckles while driving them using a pully engine above the joint.