Laser Proximity Detector

Customized version of https://www.thingiverse.com/thing:468917 Created with Customizer! https://www.thingiverse.com/apps/customizer/run?thing_id=468917 I created this custom enclosure for this Laser Proximity Detector. https://www.amazon.com/gp/product/B00NJNYQ9G I added holes in the lid for the laser emitter and the lensed detector. I'm using this setup to detect holes in a wheel to measure speed in feet per minute of a cart. The display is this unit: https://www.thingiverse.com/thing:3352007 The backstop is needed because the laser will bounce off objects on the other side of the wheel. I glued static foam to the backstop which absorbs the laser beam and keeps it from bouncing back. Only the spokes of the wheel reflect the beam back to the detector.