pic: Team 121 Arm Proto

I saw some comments about our arm prototype that was featured in the American Robot video. Here is a pretty good picture of the prototype in action. Alot of different people shared ideas to come up with this concept. I welcome any suggestions, questions, or comments.

I noticed that some people who watched the American Robot video commented on our arm design. Here is a picture of it in action. We welcome any comments or questions. I hope that by sharing ideas we can all end up with better mechanisms for this years competition.

Good Luck


Can you explain how it stacks, the picture isn’t exactly clear on what it does to stack.

The arm works like a human arm: with a shoulder and elbow joint and hand (the part that picks up the tetra). You can use your own arm to test it out. With your palm up and arm straight, “drive” into a tetra, fold your arm up at the elbow until your hand touches your shoulder. Then rotate your shoulder up so your hand is above your shoulder and “drive” to a goal. When you reach a goal, rotate your elbow down so your arm is straight, “drive” forward so the tetra is over the goal, and rotate the shoulder joint down so the tetra is neatly placed on top of the goal. Back out and fold the arm back up for easy driving. Hopefully from the picture you can see the parts and motion I was describing. Hope that helps.


I don’t understand, maybe it’s the angle the picture is at at??~ how is the tetra remaining on the arm?

nevermind, just saw the video grrrrrr :yikes:

Go here http://www.joemenassa.com/Robotics05.html to get more detailed views.

This is a simple 2 jointed arm. It has a shoulder and an elbow joint that fold up. it places a tetra by pointing the elbow toward the top of a goal and the unfolding the forearm so the tetra curls onto the goal. If you watch the American Robot video you can see an early version of it in action.

Good Luck to everyone!