Hi Chillin Out, thanks for your reply. Sorry, I'm not sure where the metal arm is you're talking about. The 'fingers' sit at 2o'clock when I look at them if that makes a difference. There's a note on the unit saying not to turn the cog by hand, but, in my usual way, I thought I would try. When I tried to move the big cog at the end under the cover, I couldn't move it -should I be able to rotate it by hand? If there's a possibility of breaking it, which way should I turn it - clockwise or anti-clockwise?

Thanks again!