St. Paul students make windmills
Wednesday, March 28, 2012 4:40 AM
Round and round it goes, if it survives the LawnBoy, nobody knows...
Emma McBride works on a windmill project. (Chatfield News photo by Gretchen Mensink Lovejoy)
First, it's got to catch wind.
"Which one went around the fastest?" inquired IBM employee Ryan Kivimagi, speaking to St. Paul Lutheran School students as they completed constructing and testing their Rube-Goldberg windmills during his annual IBM Engineering Week visit to Chatfield last Thursday afternoon.
They were simple windmill blades constructed from an assortment of household oddments, including rubber bands, plastic cups, dowels, popsicle sticks, plastic spoons, paper clips, tape and a manila file folder.
Students built windmill assemblies, then placed them on a pin connected to a switch that changed the direction of rotation, at which point Kivimagi and Hitachi employee Denise Wermager used a leaf blower to create high indoor winds, resulting in varied measurements of velocity and voltage generation.
The engineering experimentation began as Wermager handed out the kits and gave instructions.
"We're doing a windmill project using a leaf blower that will test how well your windmills are built. What types of skills do you think are important in engineering? What you're doing is engineering, or designing something. That's right, science and mathematics."
She pointed out that "even a bottle of water has been affected by an engineer - the water bottle was designed to fit a person's hand."
A water bottle was designed using a set of rules, therefore, the Rube-Goldberg windmills the students were to build had a set of rules for their design, beginning with "do not break the centerpiece of the windmill... we need that back."
The other rules were that the students could cut up the manila folder or use it to map out their plans for the finished product, they could ask for plastic drinking straws and masking tape, and from there, there were no rules.
The three groups of five students quickly realized the usefulness of opening the centerpiece to install straws in its side-drilled holes, then began reinforcing the straws with popsicle sticks, the dowels or the plastic spoons, which they turned sideways as wind-catchers. The question of the moment was whether to add manila paper blades between the spoon blades, and most attempted it in one fashion or another, adhering the paper to the straws with tape, paper clips, rubber bands and elbow grease.
The testing process was exhilarating - Kivimagi and Wermager warned students to clear the front of the room as teams' windmill assemblies were mounted on the pin and set into motion by the leaf blower, as parts "could go flying and the windmills could be demolished by testing."
Students cheered and championed their team's design as parts flew on other teams' windmills, and cheered on other teams as success was almost attained.
The most voltage generated on a scale of one to 10 was a high-end two, with room for improvement and more learning.
Wermager stated that "even engineers re-test and learn about the flaws in their products so that they can explore the cause of the problem or destruction and find what works... try it over and over and over again to get better and better."
"What do we do next?" was the question of the moment, as re-design followed more testing and re-design. One team observed, "We have to have a backup plan in case the first one doesn't work."
Going back to the drawing board led many of the students to add plastic cups to their designs, which proved useful in the last round of testing when Kivimagi asked them "Which one went around the fastest?"
He explained, "It's the one with the most parts to catch the wind."
Still comparing design strategies an hour and a quarter later, the students thanked Wermager and Kivimagi for their visit and advice on how to capture the wind.