[Carter12s]

Wow that is cool. Can I make sure I am getting this right thou? you have a stationary gear mounted at the pivot point of you shoulder, so that as you rotate, the chain linkage from this gear to the wrist would keep the wrist at a constant relative angle, except that by using two different sized gears you get the angle of the wrist to change as a function of the angle of the shoulder! That is really impressive!

The only place I have seen a similar system is inside the explosive ordinance disposal arm used on Foster-Miller TALON robots. Even thou I work with a talon and the arm almost every day, I never thought to use it on our FIRST robot, and the TALON system is simpler since because they use same sized gears they simple keep the joints relative angles the same.

That is just fantastic to see! If I can ask what gave you the idea to use a linkage like that?