Elsewhere I have written about the power of projects.  There is no educational experience that quite matches making an example of what you are studying, or even a model of it.  But the experience of building or making something goes beyond the item itself and can introduce you to skills, tools, and ideas that you might not have had in mind when you started.

Last year we decided to clear out a weedy old flower bed in the front yard and turn it over to growing tomatoes.  While digging out the undesired vegetation, I found a length of steel pipe some fourteen feet or so, spotted with rust.  I pulled it free of the clutching weeds and loam and, when I tossed it aside, it rang with a pleasant sound.

This gave me an idea to take the pipe and turn it into a set of wind chimes.  It sounded like a simple project; just cut the pipe into different lengths, and string them up somehow.  Simple, but artless.  That prompted me to not get to it all at once.  That was a good thing because it gave me a chance to mull over the idea.  I decided I didn’t want just a bunch of random tones clanging, I wanted music, or something close to it.

My windchimes project, made from an old piece of pipe found in the garden.

This led me to decide that a set of five chimes would be a good number.  A trip to Wikipedia gave me an overview of several musical scales and modes.  One of these was a pentatonic scale, the Japanese Yo scale. (http://en.wikipedia.org/wiki/Yo_scale).  This scale in western notation goes D, E, G, A, B.

But I also learned a little bit about how chimes actually work from my spouse who is much more musically literate than I am.  It turns out that when a chime or a plucked guitar string or some other long, freely vibrating object vibrates, there are two points called nodal points, around which the object vibrates.  Think of the zero point of a cosine wave.  These points are found a distance of roughly 22% of the length of the object from the ends.  The practical upshot of this is that if you suspend the chime from one of the two nodal points, it dosen’t clank, but gives a nice, sustained gong.  This is because whatever is holding up the chime is touching it where the chime is hardly vibrating at all, and so does not interfere with the sound.

But when you are talking about a scale, you aren’t just talking about notes on a staff, you are talking about intervals between the notes.  These are expressed as ratios.  I kind of like low-pitched chimes; they have a deeper, mellow sound.  So my problem was the following: how do I cut a fourteen-foot pipe in such a way that the five pieces that result ring at the same mathematical intervals found in a Japanese Yo scale?  I wasn’t interested in the exact notes, but I wanted the same intervals.

I found some information on the web that provided ratios for different musical intervals assuming an equal tempered scale (as opposed to a strictly mathematical scale such as the Pythagorean scale).  I created a spreadsheet that let me play with different lengths for the lowest tone, while calculating the other lengths and comparing them to the 112.14 inches of pipe I had to work with.
So what else did I learn?  Now we come to the engineering part of the job.  I learned that cheap hacksaw blades don’t last long when cutting thin steel pipe.  I learned that high-speed steel drill bits are inferior to tungsten bits, which do not cost that much more.

I found a circular piece of wood at a craft store to use as a top platform, complete with a convenient hole drilled in the center.  With five chimes, I wanted five points from which to hang them, which meant dividing up a circle and marking the spots for the hanging points one fifth of the way around the circle.  A protractor helps accomplish this, but one must be careful and pay attention and always, check your work.

I learned a few other things, like the value of sanding and priming a wooden surface before painting it, and how to use duct tape and a Phillips screwdriver to push a length of clothesline through a tennis ball used as a damper so that the chimes don’t bang into each other too much (They were a little too close together, I thought).   But the point is that doing a project like this teaches far beyond the ostensible point of the enterprise.  And the extra tidbits you pick up will come in handy elsewhere.  Count on it.

One other important thing you need to remember when doing  a project is a bit of advice I received from my good friend Dr. Shawn Carlson: when you do a project, assume that you will throw away the first attempt.  That’s where you make all your–necessary–mistakes.  Over the years, I have come to appreciate the soundness of that ego-preserving advice.