Wednesday, May 15, 2013

2.007 Wrap Up

I have shamelessly stolen many photos for this post.

The first of which is me in a Tyvek suit going around the last corner in our gokart hill climb competition. 

And here's a bit of drag race action.

Race day was long and exciting. We got to see all the cars perform and had a blast doing it. The people in this section are all really cool. I wish we had spent a bit more bonding time throughout the semester.

Zoran performed quite well. We placed 5th in the drag race and 3rd in the hill climb. Instead of being raw speed, the scores are your time in seconds multiplied by the watt-hours consumed. It's an interesting metric that balances efficiency and quickness pretty well. Here's a graph I stole of the results.

Closer to the origin is better. My marker is the white star which is barely visible (just below 20Wh and 90s). My partner Carolyn is the black triangle. She's 3/4 the person I am (weight wise) and so had a considerably better score.

The Thursday following our competition was the main 2.007 event, a game based off of Operation. We brought the karts to Johnson arena and had them next to the main competition area. For a while people sat by their karts and answered a few questions but soon boredom set in and the shenanigans started. 

Karts were zipping around behind the stage and I got to try a good number of them for the first time. We had a "parade" and then presented Charles with a small gift, Chibi-Dice. Good job team.

It turns out that putting walnut in the laser cutter is a very good idea. 

So, all the festivities are over. How about some reflection.

In my opinion, the most unique part of Zoran is the parallel steering. The arrangement gives a very wide range of motion and allows us to have a turning radius of about four feet. We confirmed just how un-intuitive the setup is when a 2.007 professor (who will remain nameless) hopped on the kart and gave the handle a big counter-clockwise twist. Cue mini heart attack. Luckily the linkages are made out of steel and bent back reasonably straight. Even with that, some of the other karts are even more confusing to steer. One kart has two levers next to the seat which isn't unreasonable, some tractors have a similar setup. However, the levers operate in the exact opposite way you'd expect them to. The kart is also very quick which makes for a lot of slightly terrifying near misses with walls, people, and other karts as you drive around. It's got a wonderful pleather seat as well which makes for an overall comfy scary, fun experience. 

As best I can tell, just one other team went to extra lengths for the aesthetics of their kart. The aptly named PandaKart featured a custom waterjet steering wheel and brake pedal. I'm sure it was fun to drive, I wouldn't really know. It's also a tadpole style kart but has a much shorter wheelbase. I couldn't fold up enough when I had my test drive and was restricted to operating the pedals with my hands. The creators had no problem with fitting on the kart although the seat cut them up a bit before they taped the edges.

If we had to do it all again I think a bit more effort in making our kart more comfortable would be time well spent. The bolts and wooden paneling left bruises in many spots on my legs after competition (confirmed with Carolyn). Changing the seat geometry or adding padding would be nice. 

Our motor ended up being a bit undersized. Most of our initial calculations and some of our tests were based off of a 36 volt electrical system. When we made the switch to 24 volts the kart got a bit slower and the maximum output power of the motor decreased. Making the changes meant reliability (and so were necessary) and I'd still rather have a pretty fast go kart that always works than a really fast go kart that kinda-sorta works.

Overall this was an excellent experience. Going from SolidWorks to a real thing (that works like you said)  is always satisfying. All of my CAD to real life efforts so far have been static and not too complex, like amplifier cases, so tackling this project was especially gratifying.

I really like project classes. I told Charles he should offer a battlebot section. He's obviously thought of it before. If it becomes a thing I might have to find a way to retake 2.007.

Until next time.