$fn = 33;

height = 40;
width = 60;
b = 3;
triagleheight = 5;

M4HoleDiam = 4.4;

holedistance = 10;

// main call
angle_bracket();

module angle_bracket() {
    render() difference() {
        frame();
        holes();
    }
}

module frame() {
    // x plate
    cube([width, b, height]);

    // y plate
    translate([b, 0, 0]) rotate([0, 0, 90]) cube([width, b, height]);

    //bottom triangle
    translate([b, b, 0]) stabilizetriangle();
    // upper triangle
    translate([b, b, height - triagleheight]) stabilizetriangle();
}

module holes() {
    // y holes
    translate([0, holedistance, height - holedistance]) YM3Hole();
    translate([0, width - holedistance, height - holedistance]) YM3Hole();
    translate([0, holedistance, holedistance]) YM3Hole();
    translate([0, width - holedistance, holedistance]) YM3Hole();


    translate([holedistance, 0, height - holedistance]) XM3Hole();
    translate([width - holedistance, 0, height - holedistance]) XM3Hole();
    translate([holedistance, 0, holedistance]) XM3Hole();
    translate([width - holedistance, 0, holedistance]) XM3Hole();
}

module stabilizetriangle() {
    linear_extrude(triagleheight) polygon([[0, 0], [0, width - b], [width - b, 0]]);
}

module YM3Hole() {
    rotate([0, 90, 0])cylinder(h = b, d = M4HoleDiam);
}

module XM3Hole() {
    rotate([270, 0, 0])cylinder(h = b, d = M4HoleDiam);
}