Module 1.5 Sector Gear 8 mm Hub
A 120° sector gear with 20 involute teeth (module 1.5, 20° pressure angle, 45 mm pitch radius, same as a full 60T gear) on an 8 mm bore hub. It locks to the shaft with an M3 set screw and a captive nut. Use it to drive a pan/tilt, elevation or gripper joint through a limited arc against any standard M1.5 spur pinion, so you don't need a bulky full gear. The teeth are thinned slightly to give FDM backlash, and there are two M3 holes for bolting on an arm or link.
mechanism sector-gear gear 8mm-shaft