module c_channel_beam(length, width, depth, thickness, suppress_shopping_outputs = false) {
    translate([-width / 2, 0, -length / 2]) difference() {
        cube([width, depth, length], center = false);
        translate([thickness, thickness, 0]) cube([width - thickness * 2, depth - thickness, length], center = false);
        translate([0, depth, 0]) cube([width, thickness, length], center = false);
    }
    // Shopping
    if (!suppress_shopping_outputs) {
        echo(str("Rectangular Aluminium channel beam: Rectangular Aluminium channel beam ", length, "mm x ", width, "mm x ", depth, "mm x ", thickness, "mm - x1"));
    }
}

c_channel_beam(500, 19, 19, 1.6);