Stack Light: EL817 Optoisolator Case

Rather than let the boosted optoisolators flop around:

Stack Light – controller hairball wiring

A small case seemed like a Good Idea™:

Optoisolator Case – OpenSCAD

The little hex standoffs have M3 threads, although 6 mm screws are about as much as they’ll take. The recesses have clearance for the boost transistor underneath the PCB, but it’s your responsibility to not let random wires get in trouble with the exposed circuitry:

Optoisolator case

A strip of good foam tape sticks it to the controller:

Stack Light – controller wiring

Admittedly, the stack light wiring remains something of a hairball, but it’s in a good cause.

The OpenSCAD code can build as many cavities as you need:

Optoisolator Case – x5 – OpenSCAD

The OpenSCAD source code as a GitHub Gist:

	// Optoisolator case
	// Ed Nisley – KE4ZNU
	// 2025-01-09

	include <BOSL2/std.scad>
	include <BOSL2/threading.scad>

	// Number of isolator mounts
	NumMounts = 2;

	/* [Hidden] */

	Protrusion = 0.1;

	PCB = [40.5,15.5,1.6]; // optoisolator PCB

	LipWidth = 0.8; // support lip under PCB

	Margin = [8.0,3.0,4.5]; // clearance around PCB

	BaseThick = 3.0; // underneath

	Block = PCB + [2Margin.x, 2Margin.y, (Margin.z + BaseThick)];
	echo(Block = Block);

	HolesOC = [9.5,10.0]; // M3 mounting holes (upper left / lower right)

	$fn = 3*4;

	//———-
	// Construct one mount

	module Mount() {

	union() {
	difference() {
	cube(Block,anchor=BOTTOM);

	up(Block.z – PCB.z)
	cube(PCB + [0,0,Protrusion],anchor=BOTTOM);

	up(BaseThick)
	cube(PCB – 2*[LipWidth,LipWidth,0] + [0,0,Block.z],anchor=BOTTOM);
	}

	for (i=[-1,1])
	translate([iHolesOC.x/2,-iHolesOC.y/2,BaseThick])
	threaded_nut(5.0,3.1,Margin.z,0.5, // flat size, root dia, height, pitch
	bevel=false,ibevel=false,anchor=BOTTOM);

	}

	}


	//———-
	// Mash together as many mounts as needed

	union()
	for (j=[0:(NumMounts – 1)])
	back(j*(Block.y – Margin.y))
	Mount();