module inner_wheel ()
{
difference() {
cylinder (h = 10, r = 30, center = true);
// cylinder (h = 10.75, r = 1.3, center = true);
color("Red",0.5)rotate_extrude(convexity = 10, $fn = 100)
translate([27+20, 0, 0])circle(r = 20, $fn = 100);
}
}

module shape_wheel()
{
difference() {
cylinder (h = 10, r = 35, center = true);
color("Red", 0.5)rotate_extrude(convexity = 10, $fn = 100)
translate([30+20, 0, 0])circle(r = 20, $fn = 100);
}
}

module outer_wheel() {
difference() {
cylinder (h = 15, r = 27, center = true, $fn=100);
inner_wheel();
}
}

//inner_wheel ();
//shape_wheel();
//outer_wheel();

difference() {
inner_wheel();
cylinder (h = 10.75, r = 1.8, center = true);
}

/*difference() {
shape_wheel();
inner_wheel();
}
*/