I need to cut a decorative spiral with a 5mm pitch. My 260 will do a 5mm thread but I need to change some gears. For smaller threads you use the 18T gear. For larger threads you use the 45T gear. The gear that's not in use is used as a spacer on the bottom cluster. For the life of me I can't see how to swap the 18T and 45T gears. There doesn't seem to be room for the 45T gear as the setup stands. Can someone shed some light please?