The saga: My original idea was to build a robot that could make organic molecules out of marshmallows and toothpicks. However, this was not possible for me. Here are some photos of two parts of this prototype, the toothpick thruster and the marshmallow conveyour belt.

(I have to admit, watching the marshmallows float down the conveyour belt and drop into the little compartment was fun... just the idea of candy on a conveyour belt, to me, is cute.) Unfortunately, the toothpick thruster did not have enough thrust to pierce the marshmallows.

On to the next idea... Two turning wheels (either vertical or horizontal) which hold and mesh styrofoam balls of 1.5" diameter. These balls started out with velcro strips glued to them. However, I encountered quite a few glitches with this prototype.

I tried to have the balls held onto the wheels by small velcro circles, but these held the balls too tightly. When the balls were supposed to come off of the wheels, they would not. I built a spatula contraption to try and scrape the balls off of the velcro, but this spatula contraption worked miserably. I tried to make holders for the balls out of cups, but to no avail. The balls in cups were too far apart to stick together with velcro.

Thus, I turned to magnets. The first magnets I bought were pathetic. They did not like the steel tacks I bought to go with them. They were similar to those magnetic poetry words that barely stick to the refrigerator. So, Lyn suggested that I use stronger magnets! And what a suggestion that was! Lyn loaned me his strong magnets, which loved my steel tacks and made me very happy!

It was off to the hardware store, full of adrenaline, to buy more steel tacks and magnets! I'm not kidding about the adrenaline... I was very frustrated with everything else I had tried up to that point. When I realized that this idea had potential, I was extremely excited!

I made a pit stop at Radio Shack for no reason than the fact that it and the hardware store were in the same plaza.... I marveled at the soldering irons and various colors of LEDs.

Now, my robot consists of a crane with a magnet glued to a string, one wheel with flat surfaces for the magnets and little cup-chairs that hold the balls, and a remote control with four touch sensors. My robot's wheel mechanism looks like a Tilt-A-Whirl, hence the name Whirl-A-Carbon.

My crane is not the strongest thing in the world... It can only lift propane without significant help from me on a good day. However, building this robot has given me even more respect for nature. It was hard to design, build, and program a robot that can build molecules out of styrofoam balls, steel tacks, and magnets. It is amazing that molecules form without outside (eg., human) intervention faster, sometimes, than I can blink my eyes. This is why I love chemistry! Chemistry never lets me forget how complex and how beautifully engineered everything, especially natural but also man-made, in this world is!

The programs: The first program was one I wrote when I thought that a reflectance (infrared) sensor was a good idea. I found out (the hard way, as always) just how distance sensitive these sensors are. I found it impossible to set a threshold for black and white that I thought was resonable and get the program itself to work at the same time. The sensor seemed to think that the black and white panneling I had glued to the wheel was not both black and white but either all black or all white (usually black). I had taken some of the code used for the SciBorgs that Robbie and Lyn made and programmed and modified it so that it would work with my robot (or so I thought).

Out of frustration with the infrared sensor, I wrote another program that used touch sensors to control the crane and the wheel using two Crickets (one Cricket for the crane and one Cricket for the wheel). At first, I had the Crickets trying to communicate (send an IR signal) when one task was finished. I realized that with the way I wrote the program, it was more logical to have everything controlled by separate touch sensors rather than partially by touch sensors and partially by infrared Cricket cues. Thus, I created a remote control, much like the one I had with my first remote-controlled car (which came from Radio Shack). There were buttons to press for the car to go forward and backward, and a small and restricted joystick for turning. I was unhappy because the remote-control was still attatched to the car by wires!

Ironically, this is the situation I have found my robot in, minus the unhappiness and the small restricted joystick. One switch makes the wheel turn on and spin around, one switch makes it stop turning. One switch makes the crane bring the magnet up, one switch makes the crane let the magnet down. Something I learned in PHYS 107 applies beautifully here: The simplest answer is often the best/correct answer.

Modifications: As much as I love steel tacks, the fact is: magnets are more attracted to themselves than they are to steel tacks, no matter how sharp or nice the steel tacks may be. So, I made another type of ball to be used in the Whirl-A-Carbon that have their own set of drawbacks. I removed the steel tacks from some of the balls (such a tragedy!), and scraped out a dent on the top of a ball and on the bottom of a ball, each the size of a magnet. I glued the magnets into the dents, but hot glue and styrofoam (and my finger) don't mix, so I tacked a paper strip to the ball over each magnet. While these balls hold together more tightly, they are also much heavier than the steel tack-filled balls. Unfortunately, weight and my crane are examples of two more things that do not mix. I would chnge the gear raio in my crane to make it stronger, if I had to do this project again. I would also experiment more with different ways I could set up the magnetic balls.

I feel that within the time constraints of this Wintersession course, I attained my goal of building an organic molecule generator. I wish I had more time to change things about the system and make things absolutely perfect, and I wish I could have worked a bit faster than I did. However, I feel that the pace I worked at was not too strenuous, but I also made a lot of progress very quickly. I also wish I had been able to get the infrared sensor to work. On the other hand, I always wanted to build my own remote-controlled machine. Now I have fulfilled that goal, as well!