Comment by coldsmoke

Do you mean 10 minutes? He lines it up with Polaris, so it only needs one axis of rotation. But I guess the alignment isn't that good since it is just eyeballed, but it should work for exposure times much longer than 10 seconds. He is even rotating the screw every 15 seconds which wouldn't make much sense for a 10 second exposure. =) Clever little project in any case. Thanks for sharing the video.