$fn = 60;
Delta = 0.005;

D_i = 42.7;
D_a = 46.2;
D = 75;

M = [3, 5.5+0.15]; // Schraube+Mutter(+Toleranz)

difference() {
	union() {
		difference() {
			cylinder( d=D, h=5 );
			cylinder( d=D_i, h=20, center=true );
			for (a=[60:360/3:359]) rotate([0,0,a]) translate([(D-14)/2,0,0]) cylinder(d=4, h=15, center=true);
		}
		mirror([0,0,1]) difference() {
			cylinder( d=D_a+10, h=10 );
			cylinder( d=D_a, h=50, center=true );
		}
		intersection() {
			translate([25,-5,-10]) cube([15,10,15]);
			cylinder(d=D, h=40, center=true);
		}
	}
	translate([20,-0.5,-11]) cube([20,1,20]);
	translate([(D-10)/2,0,-5]) rotate([90,0,0]) {
		cylinder(d=M.x, h=40, center=true);
		translate([0,0,3.5]) cylinder(r=M.y/sqrt(3), h=20, $fn=6);
	}
}