Our robot was highly dependent on mechanical devices. We decided early on to rely on potential energy devices whenever possible. We had a few reasons for this. The first is that these devices respond more quickly (in general) than using motors. They are also lighter and often more reliable. Another reason is that they are easier to build. Also, that left the motor ports open for other uses. An additional driving factor was that we are all studying as mechanical engineers, and we like mechanical devices better than electrical ones.

The biggest mechanical aspect of our robot was the arm. We launched the arm using a slingshot-type device. We had rubber bands tied between two posts on either side of our robot. We then pulled the arm back, stretching the rubber band. This is where our first mechanical triggering device came into play. We put a one by four beam on the arm, which tied to the axle of the motors that would up the arm. When the motors started, it pulled the beam off of the arm, and it launched.

On the arm was our grasping device, better known as the Jaws o’ Death. These were completely mechanically activated. It was basically a hinged jaw that was held shut with a rubber band. We opened them, and stuck our second mechanical triggering device on. It consisted of two Legos stuck together that we propped the J o’ D open with. This way, when the arm hit either the block or the ground, the propping pieces would break away and the jaws would snap shut with block-crushing force.

Our drive train was the mechanical aspect of our robot with which we had the most difficulties. We started out by using a worm gear, as we knew that the more gears we used the more power we would lose due to friction. The worm gear gave an extremely large mechanical advantage, so it would be about the only reducing gear we would need. However, as it turns out, there is a large horizontal force that is associated with the gear. The combination of the high rmps and the horizontal force created an excess of friction. In fact, after we ran our robot for a little while the two rubbing pieces fused together.

To fix this problem, we constructed a drive train that implemented the typical gear setup. Because our robot was quite tall (for clearance of the blocks), we had to transfer the power from the top to the bottom. To do this, we used the chains. We had a problem with the chain breaking. This was particularly annoying because it was quite difficult to put them back on, as our gear train was completely hidden in the superstructure of our robot. We solved this problem by doubling the chains on each side. It took about an hour to do this, but we rarely had a chain break after that, and never had all of them break in one go. This was basically what we were trying to avoid, as that would completely immobilize our robot.