eps = 0.01;
infty = 100;

width = 30;
depth = 10;
hole_d = 3.5;
wall_angle = 40;
hole_angle = 10;
hole_wall = 2;
wall = 1;
front_h = 0.5;

difference() {
	hull() {
		translate([-width/2, 0, 0])
			rotate([hole_angle, 0, 0])
			cube([width, eps, front_h]);
		intersection() {
			translate([0, depth, 0])
				rotate([hole_angle, 0, 0])
				translate([0, 0, -infty/2])
				cylinder(r = hole_d/2 + hole_wall, h = infty);
			translate([-infty/2, -infty/2, 0]) cube(infty); // z > 0
			translate([0, 0, wall])
				rotate([-90+wall_angle, 0, 0])
				translate([-infty/2, 0, 0]) cube(infty); // upper side
		}
	}
	// screw hole
	translate([0, depth, 0])
		rotate([hole_angle, 0, 0])
		translate([0, 0, -infty/2])
		cylinder(r = hole_d/2, h = infty);
}