SG90 Twin-Groove Tendon Spool
A two-groove tendon spool that screws onto an SG90/MG90S servo horn. It pulls a flexor line in one groove and lets out an extensor line in the other, so one servo drives a tendon finger both ways. It is 37 mm across and 22 mm tall, with 16 mm drums, a Ø7.5 mm bore so a screwdriver reaches the horn screw, a Ø9 mm recess for the horn hub, M2 clearance holes at radii of 12 and 15 mm on four arms, and Ø1.6 mm tie-off holes.
robotics sg90 servo tendon