This was my first commercial project. They are pieces to join extruded aluminium frames together.

They were being fitted into frames where the ends of the extrusion were blocked, so sliding in for the end was a no-go. The solution was inspired by t-nuts. Place it in the slot in the narrow orientation rotate 90° to lock it in.

I think I printed about 2,000 of these.

$fn=80;

module frame() {
    difference() {
        translate([0,-1,8/2]) cube([14,20,8], center=true);
        translate([0,-1,(8/2)]) cube([10,20.5,4], center=true);
        translate([0,-1,6]) cube([6.4,20.5,4.1], center=true);
    }
}

module nut() {
    intersection() {
        cylinder(d=10,h=4);
        translate([0,0,4/2]) cube([10,4,4], center=true);
    }
    
    translate([0,0,8/2]) {
        intersection() {
            cylinder(d=6.5,h=2);
            translate([0,0,2/2]) cube([10,4,2], center=true);
        }
    }
    
    translate([0,0,6/2]) {
        hull() {
            translate([0,0,(2+6)/2]) cube([10.05,4,2], center=true);
            translate([0,0,18]) translate([0,0,(2+6)/2]) cube([7.05,4,1], center=true);
            translate([0,0,18]) translate([0,0,(2+6)/2]) cube([9.05,0.5,1], center=true);
        }
    }
}

%frame();
translate([0,0,2]) nut();

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