Hateful Hamster lives again! Not only does it live, but it jumps into the pond, swims across the pond, collecting balls along the way, climbs up out of the pond and then...stops. Ya, so the last part is a bit of a let down, but at least he didn't sink :)
So, before the ingenious success of Hateful, a lot of thought and work had to be done. Wednesday I went into the shop for 3 hours to work on keeping Hateful afloat. Will decided she needed to take a day off from the shop, so I was on my own. The first problem I decided to tackle was the water leakage problem. For this entire term that had been a major problem. Water was inevitably going to leak from the small gap where the rod was coming out of the robot and spinning the paddles, but that amount of water should be relatively insignificant in the overall scheme of things. However, gallons of water (figuratively) were leaking into Hateful. There was a direct correlation between the amount of time he spent in the water and how much of his body was submerged under the water. The thing was...duct tape is awesome (don't get me wrong) however it is not the best choice for forming water tight seals. The water was leaking in between the duct tape and getting inside Hateful from all sides.
I am pretty sure I came up with the solution in a dream. Yes it is weird/cliche, but I woke up Wednesday morning and suddenly came up with the answer. Hot glue as much of the foam shell as possible directly to the board, leaving only a little area where we would have to make a flap to open and close to get to the electronics inside. It was such a simple solution, and now I wonder why we didn't think of it earlier. First problem solved!
Now, for the second problem...Hateful's foam "belly" was rubbing on the ground when it was driving around on land. In fact, in some areas it was so large that it was preventing the wheels from making enough contact with the surface (and so it could not drive). Hateful needed to lose weight, and I needed to figure out what diet was right for him.
Since Hateful is a wedge (pyramid), the shell should have 1 angle from the point where y is zero to the point where y is the height of the foam that we determined would be appropriate (so that the wheels would not touch the ground, but also so that all of the electronics and gear boxes would fit inside). Long story short, the angle was too small, and when is we made the shell to that exact specification, the waterproof box would not fit inside. Easy fix! I moved the waterproof box as far into the back of Hateful as possible (where the height of the foam was greater and could encase the height of the box) and then put the battery where the box used to be. This worked very well, but I still needed to make more calculations and a few slight changes to the shell and its angle. In the end, I drew out all of the pieces I needed to make, and started working on molding the foam.
The 3 hours went by fast on Wednesday, and since I had spent so much of my time drawing up plans, I was only able to make and attach the front part of the shell. That left me with a lot of work on Thursday. Will was there on Thursday and we were both able to work from 1-5pm (I had a basketball game, but it was at Home and so I didn't need to be at the gym until 6), so we got A LOT done! We finished the entire shell and everything was ready for Friday's demonstration. The only thing with staying in the sub-basement of Spalding for 4 hours straight, surrounded by the smell of oil and metal, is that you start to get a little bit loopy...
So, I need to preface this with an explanation of how to mold the foam... You cannot cut the foam with a knife, because it just leaves jagged ends and it falls apart. So, the way to cut the foam is to melt it with a hot wire. A problem then arises when you try to glue the foam together, using hot glue. Obviously, if the glue it hot enough, it will melt the foam, and you are left with less than you started with (instead of more...). That is what happens when you use the ME Shop's glue guns. They have one setting, and it is HOT! We think this is where some of our problems with leakage came from. So, we needed to find a new way to glue our pieces of foam together...
Luckily for us, our neighbors at the bench right next to us had nice foam creations, and so I asked how they glued the foam together. It turns out, he bought a hot glue gun online that had 2 settings of hot glue, one which would not melt the foam. He told us that we could borrow his hot glue gun to make our robot. As it was getting later and later, I started talking about the glue gun, and how it was a good investment. Will wanted to know the reasons for having 2 settings on a glue gun. I mean, why else would you need the low setting besides gluing together foam? While our neighbor was coming up with legit reasons for needing a 2 temperature glue gun, I blurted out "to pick up guys." Yes. It makes no sense, and no one in their right mind would have given that as a reason, but you have to remember...I still have a concussion and I was down in that shop for 4 hours straight...
Anyways, that started a discussion about which glue gun (the nice 2-temperature blue one with a light, or the crappy yellow one from the shop) would attract guys more, and if you would take the glue gun with you on a date, or to your wedding...etc. We had about 5 people involved in this discussion, when Will finally ended it all by saying "we will never get any guys if we are stuck down here in the shop all the time..." And that was that. The sad reality that we had spent our entire day down there gluing foam together with a glue gun...no matter how impressive the glue gun was, it was kind of lame. Haha! But it was fun, and Hateful was done!
Friday morning, I went into the shop to add RTV to all of the possible slots where water could leak, and then I charged the battery and the receiver. The thing was, once we connected the battery with the motors, and then sealed up the robot, we would not be able to turn it off until we ripped it apart. This posed a new problem.
In the long term, we will create extensions on the battery-motor connection, so that we can completely seal Hateful without having to get to the electronics inside. But, that day, we just had to connect it, seal it, and hope that neither the battery nor the controller would run out of power before we had to show it to the Professor. We plugged everything together at 2pm, and our trial was at 4:15. We needed to test out our robot with enough time to make adjustments, but not so much time that there would be no power left by 4. As we were testing it, I could see the Voltage going down on the controller display. I was scared, but I had hope.
Luckily, everything worked out fine! We did have to make a few adjustments to Hateful, up until 4pm! There was a hole that we had to hot glue shut, and we had to make a few adjustments to the net. But other than that, Hateful performed well! The prof seemed happy, and a few of our friends stopped by to watch Hateful in action. When Hateful made it up the ramp, I was so excited and surprised that I let go of the trigger, and he stopped right at the top. Ha! Granted, he didn't make it into the scoring bin, but at least he did everything else. The professor gave us some tips on how to make Hateful better, and finish the task, and then we went back into the shop. We didn't actually work much afterwards, because we were so relieved that it worked. The next deadline is still over a week away, but we have a lot of work to do. We have to finish up Hateful, and then resurrect Hungry...
