$fn = 40;


difference(){
    union(){
        cylinder(d=12,h=1);
        cylinder(d=8,h=8);
    }
    translate([0,0,-0.01])cylinder(d=6.2,h=30);
}


module fakebearing(){
difference(){
    cylinder(d=8,h=4);
    cylinder(d=3,h=5);
}
}