$fn=33;

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

M4HoleDiam=4.4;

holedistance=10;


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);
}