Well, its a bad potentiometer, or the potentiometer is somhow knocked loose (unlkely). If your lucky, you can get spare parts for your rudders. A potentiometer is small device used to measure resistance as you pan from position to position. Unfortunatley, these wear out. The one in my logitech stick broke in 2 weeks. Exactly to the day that the return policy expired at comp usa.
Logitich dont give no free shpping, nor do they sell spare parts.
I like thier sticks when they are new, but they are not durable, ain any sense of the word.