Gear Animation WIP

I'm working on an animation for a friend's film and the scene I'm developing is just an intricate set of gears rotating; I'm doing this all in Blender and it is taking some time to make it look right. I'm eventually going to have an entire scene filled with gears and pistons moving about...

Blender+Yafaray

Youtube Version of Video: [link]

Any tips would be appreciated

*Update: [link]

*Update 2 (best version I have so far): [link]

*there is another update of the gear animation, but I am no longer working on it and the moving animation (fly through) was rushed for the time frame my friend wanted and I'm not entirely proud of it haha (although I didn't have much time)