It’s a Captain Obvious moment, but I think it is safe to say that there is a huge difference between theory and practice. This can apply to everything, including topics as varied as art, math, music, how you organize a home school, or even parenting, in general. Experience is the best teacher and kids loves to take things apart to see how they work.
Yes, I excel at the obvious.
This was never clearer to me than when Primo was in first-grade at a private school (right before we started educating the children at home): in that situation the “teacher” was content to simply read the science text without actually doing any of the suggested experiments (if there were any at all).
As Secondo would so eloquently put it, “Böring!”
Don’t get me wrong, thought experimentation (i.e. imagination with logic) is a useful tool in the pursuits of science and engineering, but nothing brings understanding as much as actually “laying hands upon the beast.” After all, one of the benefits of being Human, as opposed to some discorporate spirit, are our five senses.
Over the years many broken toys and appliances have been “sacrificed” to feed the boys’ curiosity. Granted, the sacrifices were really beyond repair (crashed hard drives, 32-year-old microwave ovens, remote control vehicles with broken gears). As well, we’ve also built many contraptions (like the trebuchet) which are filled with many lessons.
Admittedly, we haven’t been doing enough of the hands-on experiments and explorations over the last few months; sometimes life just happens, we get re-organized and move on. In that vein, I decided that the boys should have a homeschool shop class: first lessons – learn about gasoline engines by taking one apart, reassembling it, and show that it still works. The lessons here combined math, physics, chemistry, engineering, discipline, and use of many tools; it also fits closely with where my talents lie in the home education arena (i.e., math and science). Who knows, maybe we will build something else with the engine (e.g., a go-kart or mo-ped).
So began the disaggregation of a 3 horsepower 79cc Predator 4-stroke engine (about $80 with coupon at Harbor Freight). Yes, I bought a brand new engine; the cost of failure is low enough that I can tolerate it, but high enough that the boys would take notice and want to complete the project (they know the value of the dollars they earn, thus respect it).
Secondo lost interest quickly (and is currently studying hard to become a Pokémon master), but Primo has stuck with it over the last several weeks (its been hot in the garage so things have come apart slowly, a few minutes per week, when we have the time and are not too tired from the day). In total we think we spent between 4 and 5 hours with this activity.
What follows is a slide show of the disassembly steps (captioned, most of the 50-ish photos by Primo) and a video of Primo restarting the engine after reassembly.
During the disassembly we learned about torque (how to convert for different length wrenches), tolerances, the difference between precision and accuracy, oil and gas chemistry. It was clear that this little adventure will have a lasting impact when Primo told us he understood what we were talking about when GranolaGirl’s car had a clogged breather box that caused the cam seals to blow out.
The next project will be to use this engine in either a go-kart or a motorized bicycle (although Primo is wondering if we can get a small jet engine now).
Seriously, anyone can do this with their kids, and should. The hard part will be trying to get him to write about his experience! More on that, shortly.