For our statistics class, we have been working hard on a Design of Experiments project that optimizes a paper helicopter with respect to hang time an accuracy of a decent down a stairwell. Basically, we used our statistics material to make a folded piece of paper drop as slowly as possible and land as close to a target as possible. Like many other projects in our classes, this was a class competition and pride was once again on the line.
The competition arena was a stairwell outside of our summer classroom. We were to design a helicopter that would drop 3 stories down within the 2ft gap between flights of stairs. Here's what it looked like:
My first thoughts were... NO WAY! It's a long way down and not a lot of room for error. How could we get a piece of paper to hit the target below. So the team started to prototype and stumbled across a unique design that was simple to build and worked pretty well. We chose it and proceeded with the design of experiments.
In a nutshell, the design of experiments is a statistical method to vary more than one parameter at a time and still understand the effect of each individual parameter. It's very powerful when you have lots of variables (ie. paper type, helicopter blade length, blade width, body height, body width, paperclip weights, etc) and not a lot of time to vary each one individually. If we were to individually change each variable one at a time, we would have made over 256 different helicopters. Instead we built 16, tested them, and got a feel for which variables were most important. We then focused on these important variables for design improvement through further testing and optimization.
All in all, we spent many hours on this project building around 100 different helicopters. Our final design seemed to work pretty well, assuming the AC wasn't blowing in the stairwell like it did during some of our testing. Here's what it looked like, complete with a paint job and intimidatingly named the "Hella-Copter":
Competition day came and everyone crowded in the stairwell to watch.
A near miss of the target by the competition!
More people in the stairwell.
We knew that our design was the best of what we had built, but we weren't sure how it would compare to the class's (and we really weren't sure if the AC would be on). Teammate Robert dropped the Hella-Copter and we watched anxiously as it slowly descended upon the target. It wobbled a bit, grazed the railings, and landed within a few inches of the target causing lots of "oohs" and "aaahs" from the spectators.
It landed with a time of roughly 16.5 seconds combined with the closeness to the target for an overall rank of 1st in the class! My first "win" for the summer! I now have some bragging rights! Other teams may be better at playing the Beer Game or running a simulated production facility, but my team built the best paper helicopter! Talk about real life skills... I should add this to my resume.
