Motor RPM Sensor Mounting: Bracket Madness

The first sensor bracket came from the scrap pile, but showed that it would produce 1/rev pulses from the motor shaft pulley. The positioning wasn’t quite right, so I made another bracket that put the TCRT5000 sensor at right angles to the pulley:

TCTR5000 Motor RPM Sensor - end view
TCTR5000 Motor RPM Sensor – end view

All of the sensors have a rakish tilt over their PCB, so at some point I must resolder them:

TCTR5000 Motor RPM Sensor - side view
TCTR5000 Motor RPM Sensor – side view

It might not matter, as the phototransistor on the left peers directly at the pulley, with the LED on the right acting as a floodlight.

“Made another bracket” sounds like the metal sprang fully formed from the concept. Herewith, the early contestants atop a sketch and the flat layout for The Ultimate Bracket:

Motor RPM Sensor Brackets
Motor RPM Sensor Brackets

A closer look at that final dimension sketch, because I’ll need it again:

RPM Bracket Dimensions
RPM Bracket Dimensions

The vertical size of the center section (12 mm) sets the perpendicular distance of the sensor from the shaft. The horizontal size (14 mm) controls the pulley-to-sensor spacing.

The horizontal distance from the center section to the hole on the right (10 mm) adjusts the sensor spacing parallel to the shaft.

I cut the overall rectangle with tin snips, drilled & cleaned the holes, applied a nibbling tool to the details, trimmed the corners, filed off sharp edges & spines, and it was all good.

The doodles for the first few attempts, as I don’t want to repeat those mistakes:

Bracket Doodles
Bracket Doodles

All in all, a few more hours of Quality Shop Time than I expected…