pic: arm design

[miketwalker]

I think that if the right materials are used, the structure would be good. Only problem I can see is possibly center of gravity. Having a second motor up on the second joint and holding a tetra up 9 or 10 feet along with the weight of the arm itself as well will make the robot tippy, so you have to work on problems with your COG (Center Of Gravity). But, if you keep everything else low in the base like you have it you should be ok.

I would definitly make sure you make the arms easily and quickly replacable, because if the robot does fall over it could snap them if not properly made or with other teams hitting into it.

As for the actual mechanisms, do not use pneumatics... with the height you'll need large pneumatics which waste air like mad, and you will need to wait for the tanks to refill. In 2003 we tried this with our system to knock down boxes... all of the air would be gone after 1 or 2 movements, and for a fast-paced game like this it'll hurt you. Also, I wouldn't use scissor lifts, they're very wabbly and hard to control. Yes, they do compact nicely, but they will not give you control and will not work very well lifting 9 pounds up that high, plus you wouldnt be able to turn it to release the tetra off of your hook making things hard.