TCRT5000 Proximity Sensor Mount

Having a few TCRT5000 proximity sensors lying around, I used one for the Color Mixer so folks could just wave a finger to flip the LED colors, rather than pound relentlessly on the top plate:

Color mixer - controls
Color mixer – controls

The stem fits into a slot made with a 3/8 inch end mill:

Prox Sensor Bezel - Slic3r preview
Prox Sensor Bezel – Slic3r preview

You move the cutter by the length of the sensor (10.0 mm will work) to make the slot. In practical terms, drill a hole at the midpoint, insert the cutter, then move ±5.0 mm from the center:

Prox sensor panel cut
Prox sensor panel cut

A bead of epoxy around the stem on the bottom of the panel should hold it in place forevermore.

The rectangular inner hole came out a tight push fit for the TCRT5000 sensor, so I didn’t bother gluing it in place and, surprisingly, it survived the day unscathed!

The OpenSCAD source code as a GitHub Gist:

// TCRT5000 Proximity switch sensor mount
// Ed Nisley KE4ZNU - October 2016
Layout = "Build"; // Show Build
//- Extrusion parameters must match reality!
ThreadThick = 0.25;
ThreadWidth = 0.40;
HoleWindage = 0.2;
Protrusion = 0.1; // make holes end cleanly
inch = 25.4;
function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
// Dimensions
Sensor = [5.9,10.0,7.0];
SensorHoleCutter = 3/8 * inch;
echo(str("Cutter dia: ",SensorHoleCutter," mm"));
echo(str("Cutter motion: ",Sensor[1]," mm"));
PanelThick = 5.0;
StemLength = PanelThick + 6*ThreadThick;
FlangeThick = 3 * ThreadThick;
// Flange model
module ProxFlange() {
difference() {
union() {
for (i=[-1,1], j=[-1,1])
for (j=[-1,1])
cube(Sensor + [HoleWindage,HoleWindage,2*(PanelThick + Protrusion)],center=true);
// Build it
if (Layout == "Show")
if (Layout == "Build")

5 thoughts on “TCRT5000 Proximity Sensor Mount

  1. I considered asking what proximity sensor you’d used, as it seemed an obvious omission. Then I remembered that you’re careful about such things and if I was patient, I’d find out. I considered making a flip comment about using a square cutter, then I remembered someone did invent a gizmo with a triangular cutter and gearing that cuts square holes (looks impractical and I doubt it’s available commercially, but at least the concept is out there).

    1. careful about such things

      Words other than “careful” spring to mind… [grin]

      A discussion about drilling square holes came up in the minilathe mailing list a few months ago. The magic tool is basically a broach wobbulating around a drilled hole, with no gearing necessary:

      AFAICT, the Sherline lacks enough mojo for the job, even in plastic, and it’s far too spendy for an impulse purchase. Showing off an array of square holes, now, that would be amusing!

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