// 'captive washers' spacer for NEMA 17 motor... replacing finicky washers on my X and E mounts // 12/12/12 bluecoast thickness = 2.5; //change your finished Z thickness here screw_hole_diameter = 4; //actual screw used in NEMA 17 is M3 union() { for ( i = [0 : 2] ) //the three screw hole 'washers' { rotate( i * 90, [0, 0, 1]) translate([0, 21.9203, 0]) difference(){ cylinder(h = thickness, r=5); cylinder(h = thickness, r=(screw_hole_diameter/2)); } } difference(){ //the half-ring to rule them all cylinder(h=thickness, r=19.9203); union(){ cylinder(h=thickness, r=16.9203); translate(v=[0,-20,0]) cube(size = [20,40,thickness]); } } };