Hi Miriam,
Everything is moving fine... The problem is that the dial isn't connected to anything inside the machine. I bought it off eBay, so I have no clue what happened with it prior. In my head, there's either a spring missing, or some sort of other piece, which connects to some other part to change the stitch length. Right now, there's no physical way the knob can affect anything internally, because it's not hooked onto anything. The knob is just there.