I'm all out!

Now I have to wait until sunday, when I can go get maybe an ounce or two at a local store (I don't like their rovings very much) to tide me over until the stuff I'm going to order from miss babs will get here. My new joy is working well so far, but I for some reason can't figure out the drive band. It keeps falling off. If I've got it around the smallest groove on top, do I put it on the smallest or biggest on bottom?