This activity is the first in this series to allow students the opportunity to use the miter saw and drill press, all with supervision of course! While I pre-cut the PVC beforehand (it is loud and dusty), students cut the wooden dowels down to size, and drilled small holes into their makeshift handles. My design of the rotor chopper differs slightly from the Howtoons article. I added a handle to the end of the string, which provides more stability for students to pull hard on the ripcord. They also cut strings to proper length and hotglued their propellers.
I knew the greatest challenge would not be in the build, but rather the use of the chopper. It took some practice winding the string correctly around the chopper, and learning how much force was necessary to get lift. We used the meadow so that students could launch the chopper from an elevated position.
Here's a slow mo vid of one in action. Love the diving attempt to catch it in the end.