Clockwork Bionicle Robot

With this tutorial (my first) you can build a robot out of Bionicle pieces with controllable arm movements.

Attach the upper arm pieces to the torso as shown. Then, put gray connectors (picture 3) into the middle hole in each arm.

Put the knobs and rods in the back of the torso. Next, attach the black connector pieces.

Finally, add the double gear-shaped stick, and connect it to both the arm and the black piece.

You can now add things such as a head, forearms, etc. to make it more human-looking. Also, you can add gears in specific positions to make them move when you move the arms: a very mechanical-looking touch that also assists movement if done properly.