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Tinkering as a Teaching Tool

A few days ago, I walked into a science class and was instantly reminded of my grandfather’s garage. There on a table in the corner was a dissected toaster and next to that was a dissected computer printer. Two generations of technology all parted out, so the inner genius of their design could be seen by all the students. This teacher was on to something important.

We all have had adults in our past who tinkered with stuff. Maybe this was a neighbor who could fix our bike or a family member who knew how to change the belt on the old washer. They had a fearless quality about them when it came to getting out the tools, taking things apart and putting them back together. It have mattered then, but perhaps not now, that they were good at making things work better. What matters now is that they had knowledge of how things work and a curiosity about the world of things.

My first experience with this was with a broken toaster. My grandfather took the whole toaster apart and replaced the heating element with one from another broken toaster. I was fascinated by the simple mechanism that holds the bread slices down and keeps them just the right distance from a red hot strand of metal then releases the toast to a height that allows the user to pull it out of the narrow slots without burning their fingers (usually). It was all magic to a seven year old.

I am told that antique and rare toasters sell for over six thousand dollars. That means that there are some elegant old toasters out there that folks collect. In fact there are and they have some mechanical wizardry that is a great example of the creative application of simple science principles. There are springs and levers and a host of innovative ideas around the simple act of toasting bread.

http://www.toastercentral.com/toaster20s.htm

As it turns out broken appliances are a dime a dozen. I have a couple sitting around my home as I write. These are great for teaching. The teacher who generously allow me to visit her class was teaching 8th grade science. Her focus for the week was on forces and motion. These two broken machines were not directly related to the lesson of the day but the kids made a strong connection. On the printer there was a glide bar that moves the printer head across the page. The student was showing me the way the manufacturer reduced the friction so the head would glide more smoothly (important for clear type) and how they stop it and send it back the other way at the end of one line. He thinks this is pure genius but was already thinking of better ways to do this. He could speak the language of force and motion and knew what variables were worth tinkering with. There were 4 or 5 students who filtered in throughout the day just to take something apart. Perhaps we do not do enough of that in our classes.

This working with real familiar materials is important. In a search of the web I found lots of references to dissecting toasters. It appears that engineering classes use this to help students gain an idea and appreciation of how things work and how products are engineered. What a concept!

http://wiki.ece.cmu.edu/ddl/index.php/Toaster

http://home.howstuffworks.com/toaster.htm

The idea is not limited to toasters but these appliances seem to be in good supply at second hand shops and in the junk rooms of homes everywhere. Computer printers seem to be in that same category. The next level up in the technology dissection hierarchy could be anything from speakers to blenders (careful of the sharp blades) or even the coffee maker. The coffee maker is an interesting dissection.

http://gicl.cs.drexel.edu/wiki-data/images/e/e5/ASEE.Workshop.Handout.pdf

Here you add water to the mix of the warming devices and that makes for an interesting wrinkle. These seemingly simple machines have some great science questions. How does the water get heated (it is different in different machines). How does the water move from the reservoir to the carafe? How does the machine know to shut off the heating element when the water is not moving through? What types of insulation would help to keep the coffee hot without needing more energy?

To get started with kids it is suggested that the teacher dissect some appliance on your own. If you have not done this it is a great task for a quiet evening at the table with your kids. You need a broken appliance, a screwdriver set, pliers, a magnifying glass (if you are over 50) and some curiosity. Once you have dissected something mechanical and perhaps even put it back you know the questions to ask and where the most interesting gears, motors and levers will be found. You know that you will reach points where you say, “I wonder what that is for?” That is all part of the process and valuable the entire way.

In your class this activity can be as formal or informal as you wish. There are handouts online that can be modified to any grade level or you might choose to just leave the materials out for students to explore between classes or activities.

http://gicl.cs.drexel.edu/wiki-data/images/e/e5/ASEE.Workshop.Handout.pdf

So, as the holidays approach keep your eyes open for some great old appliances. Clear a spot on a table in your room and bring out the tools. This should be fun and who knows; maybe I can fix that old toaster that has been with me since 1975.

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