Update for Z carriage rendering

Small update for the z carriage motor gear

Hardware/CYCLONE_2/Source_files/libs/gears.scad

@@ -63,6 +63,7 @@ module herringbone_gear( teeth=12, circles=0, shaft=5 ) {
 				circles=circles,
 				twist=twist/teeth
 			);
+			if (teeth>=10) {
 				mirror([0,0,1]) translate([0,0,-height/2-0.01]) {
 					difference() {
 						cylinder(r=diam/2, h=truncation_height);
@@ -72,6 +73,7 @@ module herringbone_gear( teeth=12, circles=0, shaft=5 ) {
 				}
 			}
 		}
+	}
 	
 	myGear();
 	mirror( [0,0,1] )