5 mm Shaft 20-Slot Optical Encoder Disc
A 60 mm slotted encoder wheel with 20 wedge windows at a 50/50 duty cycle, on a 5 mm set-screw hub. You get 20 counts per turn from a single slot-type photointerrupter, or 80 with two sensors in quadrature. The disc is 1.8 mm thick so it runs in the slot of common U-type optical sensors, and the windows span radius 22–28 mm. The hub takes a 5 mm motor shaft with a captured M3 nut and set screw, and two M3 clearance holes 30 mm apart let you bolt it to a printed wheel hub instead.
electronics encoder photointerrupter odometry