/* Linear units are mm */

ext_dia = 32.0;
int_dia = 6.2;
h = 10;

mnth_dia = 3.2;
mnth_ins_dia = 6.0;
mnth_ins_h = 2.0;
mnth_center_r = 12.0;
mnth_num = 4;

bearing_od = 19.0;
bearing_h = 6.0;

$fn = 64;

translate([0, 0, h])
rotate(180, [0, 1, 0])
difference() {
    cylinder(d=ext_dia, h=h);
    cylinder(d=int_dia, h=h);
    
    for (alpha = [0 : 360/mnth_num : 359.9999]) {
        rotate(alpha, [0, 0, 1])
        translate([-mnth_center_r, 0, 0])
        union() {
            cylinder(d=mnth_dia, h=h);
            translate([0, 0, h-mnth_ins_h]) cylinder(d=mnth_ins_dia, h=mnth_ins_h);
        }
    }
    
    cylinder(d=bearing_od, h=bearing_h);
}