Contraptions

When I was younger (pre-second grade), my three favorite books were How Things Work, The New Way Things Work, and Batteries, Bulbs, and Wires. I still have these books, sitting on my bookshelf alongside Human Dimension and Interior Space. They covered, from a practical perspective with many pictures and diagrams, the basic concepts and operations of everyday machinery and objects, especially with regards to the function of simple machines. That fascination with all of the possibilities enabled by basic parts remains with me today, and is probably no small part of my career in engineering.

Creating intricate machinery to accomplish tasks for us is, today, quite simple.  Take some sensors, maybe some servomotors, and a microcontroller, write a quick program, and you’re all set to do whatever it is you want to do, whether that’s water the lawn at a particular time and set of conditions, or collect data on the weather, or feed your fish when you’re not home.  Simple, straightforward, and lazy.  Lazy engineering.

Now, lazy engineering is not a bad thing.  In fact, under most circumstances a lazy engineer is a better engineer.  And the possibilities enabled by microcontrollers, servomotors, and sensors are vast, diverse, and wonderful.  I have such tools myself, in a tacklebox in my garage with various other electrical components, so that I can put together a little system to harvest ambient RF energy and convert it to heat, or water my plants, or alert me to intruders without relying on some spyware company.  Yet, whenever I consider how easy it is to slap together these basic components to accomplish tasks, and I think about engineering and design before the advent of such electrical conveniences, I feel that a certain kind of intricate, lateral, multidimensional thinking has faded.

I remember going to a little farming museum several years ago.  Most such museums have the usual array of semi-rusted plows and farm tools from the seventeenth or eighteenth centuries, which are mildly interested and not particularly memorable, but this museum had a wheelbarrow.  Specifically, it had a wheelbarrow that the owner, two hundred years ago, had jerry-rigged with a little conveyor belt and a plunger that moved when the wheel rotated.  This setup enabled the user to do nothing more complicated than walk the wheelbarrow along a row, while the modifications took care of the intricate task of planting potatoes.

Planting potatoes seems like a simple thing.  I could come up with a quick little robot that would do the same thing by putting a few servomotors together, a sensor or two, and a quick program on a microcontroller.  But this unknown farmer didn’t have such conveniences.  His mechanism was based entirely upon mechanics, a system of gears, pulleys, and other such simple machines to take advantage of the normal motion of the wheelbarrow to make a commonplace task a little easier.  Sure, modern industrial farm equipment can do far more, far faster, and a far larger scale, and largely automated or remote-controlled, but that’s not the point.  There’s something remarkable, something admirable, about contraptions like that potato planter.

It’s the same reason that I’m fascinated by mechanical clocks.  The basic principle of a mechanical clock is nothing complicated – convert some natural periodic motion into the motion of gears that will rotate at different rates to represent minutes, seconds, hours, and whatever other complications you might like to include on your clock – but how many of you could sit down and puzzle out how to make that reality?  That’s a challenge I set for myself when I was doing my undergraduate program.  I was learning a lot of systems engineering, but I felt that I wasn’t learning enough of the practical aspect of how to make these disparate systems in the first place.  To challenge myself, then, I decided to design a weight-driven clock from scratch.

Weight-driven clocks seem simple, right?  The weight, based on the pulleys or gears its suspending cord or chain passes over, will fall at a predictable rate.  Convert that linear downward motion at a predictable rate into rotational motion, step it up or down using a series of gears to achieve the precise rotational rate necessary to describe seconds, minutes, and hours, and you’re done.  Making that happen, though, and in a confined space, is a different matter.  For it to function properly, for the weight to fall at the proper rate and provide rotational energy throughout the course of a whole day without being raised back up to the top, I had to invent a basic clutch mechanism to switch between two parallel weights, one of which would only be released to begin falling after the other had reached its full extent.  The final design covered five pages of engineering paper (I insisted on doing the whole project by hand, again to prove that I could.  My only exception was to check my math with a calculator).

I never built that clock, so I don’t know for certain how well it would have functioned.  Designing it was a project in itself – building it would have required a caliber of precision machining to which I did not have ready and inexpensive access.  Maybe, one day, I will build myself an elegant, mechanical clock, like one of those antique grandfather clocks, to display in my house.  Or maybe I’ll buy such an antique.

Clocks are far from the only example of this kind of intricate mechanical thinking – we could discuss music playing devices, automata, and other contraptions – but they exemplify the kind of thinking I’m trying to prod.  It is multidimensional, indirect, and fundamental.  We can look back two thousand and more years to see the ancient Greeks moving temple doors with steam, or, slightly more modern, the devices proposed by Leonardo Da Vinci.  How many of us can even identify the intricate fundamental engineering that underpins our modern technology?  Even most engineers don’t think about it, and if they can describe it, they probably couldn’t replicate it.  We can accomplish amazing things with our modern technology – this computer on which I’m typing is just one example – but we should try not to lose sight of contraptions.