// create the donut shape that i am removing from the shaft
module donut()
{
rotate_extrude()
translate([41,0,0])
circle(35);
}
//shaft
// create the shaft, and remove the donut
difference()
{
// shrinkwrap (hull) a large radius base cylinder and a small radius elevated cylinder to serve as the core of the shaft
hull()
{cylinder(5,15,15);
translate([0,0,35])
cylinder(5,8,8);
}

translate([0,0,28])
donut();
}