Optoelectrical Rotary Quadrature Encoder Disc and Sensor Mount

thingiverse

This is work in progress. Work on a rotary quadrature encoder customized for Mr Baddeley's R2D2 v2 design is underway. The project utilizes scooter E100 motors and a modification shared earlier. The goal is to create an accurate measurement system using low-cost sensors, ICs, and an Arduino microcontroller. For optimal performance, the sensor case and encoder disc must be printed in BLACK to prevent stray light reflection. The backing of the disc should be printed in WHITE for maximum reflectivity. Encoder Disc The encoder disc consists of two parts: a black front side with slots and a white back side that reflects light. These two components should slide easily into each other. Aluminum foil or tape can also be used between the parts to increase reflectivity, but plain white plastic yields more reliable results by diffusing the light. To assemble the encoder disc, insert it over the motor's spacer behind the sprocket. Ensure a 1mm gap between the disc and the front cover to prevent rubbing when the motor rotates. Sensor Assembly Assemble the sensor by inserting three RPR220 reflective sensors into corresponding slots. Each sensor has four pins that should be guided through holes at the back of the casing. Insert two M3 square nuts into their respective slots as well. Secure the assembly to the side of the motor with the sensors facing the encoder disc's tracks using 2x M3 countersunk bolts, 8mm long. Installation requires drilling a plastic bracket with a rotary tool to create holes at a 52-degree angle from the motor shaft. To adjust sensor distance from the encoder disc, drill two pairs of holes at different heights and merge them into slots. Updates: * 09 Feb 2019: The circuit has been tested at speeds up to 27km/h, delivering motion events with 100% accuracy. * 05 Feb 2019: Huge improvements have been made in accuracy with the updated encoder disk, sensors assembly, circuit, and firmware. * 04 Feb 2019: Encoder Disc design was improved for accuracy, switching to 24 slots per track. Electronics were designed, prototyped, and tested at slow speeds. TO-DO List: * Design a PCB for the circuit. * Update this thing with complete instructions. * Create a protective cover that clips over wires.