hole-demo.scad

$fn = 100;
hole_diameter = 1;
hole_length = 2;

z_fight_epsilon = 0.0001;

module substrate(){
    difference(){
        cube([hole_diameter*2, hole_length-z_fight_epsilon*2, hole_diameter*2], center=true);
    rotate([90,0,0])
        children();
    }
}

translate([-hole_diameter*3,0,0])
substrate()
    cylinder(r = hole_diameter/2, h=hole_length, center=true);


substrate(){
    cylinder(r = hole_diameter/2, h=hole_length, center=true);
    translate([0, hole_diameter/(2*sqrt(2)), 0])
        rotate([0,0,45])
        cube([hole_diameter/2, hole_diameter/2, hole_length], center=true);
}

translate([hole_diameter*3,0,0])
    substrate(){
        cylinder(r = hole_diameter/2, h=hole_length, center=true);
        difference(){
            cylinder(r = hole_diameter/2 * 2/sqrt(3), h=hole_length, $fn=6, center=true);
            translate([0, -hole_diameter/3, 0])
                cube([hole_diameter*2/sqrt(3), hole_diameter * 2/sqrt(3), hole_length+z_fight_epsilon*2], center=true);
        }
    }