This is a simple project which involves paper tubes, a few note cards, and a rod for the windmill to turn on. Acutally, a pencil could be used for the rod. First, I drew the circles on note cards and used a protractor to mark eight 45 degree angles. Next, I cut a strip of note card which I rolled into a circle with a diameter about a half inch smaller than the two circles. Next, I cut out the two circles and glued them to each end of the rolled up strip. Then, I cut out the blades and glued them in at an angle. The base can be made in any design a person wants to use.

My students have always enjoyed this activity. First we build 4 beams out of paper. The triangle,rectangle,corrugated, and the cylinder.

I don't allow them to use tape, only glue. Normally, it requires 3 to 4 class periods (40 min.) to build the beams, test them, record the results, compare the results to the class average, and graph the results.

Overview

We build the 4 paper beams, and let the glue dry over night. We then place two desks 4 inches apart and place the beam over the space. We then slip our special testing device onto the beam and begin adding pennies until the beam collapses.... and pennies go rolling everywhere!

Beam Building Instructions

Here is a picture of the 4 beams.

Triangle Pattern

Rectangle pattern

Corrugated Pattern We used a strip of paper 12 cm wide and made 6 folds (like a fan) 2cm. apart.

For the cylinder, we cut a piece of paper 12 cm long and rolled it into a cylinder. I let them experiment with rolling the cylinders into different sizes.

Here's our devices that we used to hold the pennies.

So far, we've had a beam hold 376 pennies before collapsing.