$fn = $preview ? 50 : 100;

module nema17(length=40) {
    translate([0, 0, -length/2]){
        hull(){
            cube([42, 32, length], center=true);
            cube([32, 42, length], center=true);
        }
    }
    cylinder(4, 11, 11, center=true);
    cylinder(46, 2.5, 2.5, center=true);
}