Six Simple Machines

Machines
Not the kind in Terminator or the Matrix. But the ones that some of us might have presented in our first science fair. That is, if you, like me, were passing through grade school at some point in the '70s; they should ring a bell. Simple machines.

Simply put, a machine is anything that makes work easier. And a "simple machine" is defined as any device that requires the application of only one force to work. While Wikipedia reminds that there is some contention about this, it is traditionally accepted that there are a total of six simple machines.

These are: The Inclined Plane, The Wheel and Axle, The Lever, The Pulley, The Wedge, & The Screw. And chances are that at least one example of each exists somewhere in or around your house.

The Inclined Plane
The most common example of an inclined plane is the simple ramp. But chances are, unless your house is wheelchair-accessible, you will not find a ramp in it.

My mother's boyfriend recently capped a set of deck stairs with a ramp constructed of plywood, and covered with exterior-grade carpet. Though not the most aesthetically pleasing, it sure makes life easy for my mom's aging canine. She, the dog, simply glides down and curses back up when she is done with her business.

If you have ever moved yourself, you probably couldn't have done it without a ramp. Most moving trucks are equipped with that large metal ramp that pulls out from and stows beneath the truck's bed. Further, if you have ever visited a construction site, building in progress, you might have noticed the temporary stairs. OSHA probably doesn't love it, but more than likely it was a 2x12, angled from ground to the entrance. It provides a runner for quick entry.

In terms of your house, it is common to see two planes placed back to back. The roof, though maybe not the truest example, certainly has an incline. And unless you live in a house built in a contemporary mold, you have some section of roof that is pitched. The pitch allows the roof to, with little effort, shed rainwater. On a much smaller scale, you can think of a knife as being two inclines set back to back. You use them when you are cutting bread or insulation.

You likely have one or more ceiling fans hanging in your house. The blades of these things, tilted at an angle, do a wonderful job with cutting through and moving air. Also, think of some of the surfaces on the outside of your house. When done correctly, your exterior porches and sills (door & window) should have a slight pitch outward. This incline (or decline) allows gravity to do its thing on any water that should find its way to these surfaces.

The Wheel & Axle
I guess it would be silly if I went into a dissertation on the wheel. I mean, in my eyes, the wheel has to be one of the most significant invention in all of human history. Without it, would over-land transportation be possible? OK, you got me with the helicopter (uses inclined planes by the way.) But that is not the point of this article.

If you think about it, and excluding the obvious lawn mower or wheelbarrow, wheels are employed all over your house. They appear in cabinet drawer glides, on the bottom of your refrigerator, on your vacuum cleaner, and in sliding/pocket door hardware assemblies. In each case, the wheel makes movement possible.

This one may get overlooked, but have you ever thought that a doorknob is a wheel rotating on an axle. Even if you have leversets on your exterior doors, or fancy lever-handled doorknobs, the internal mechanism usually consists of some sort of axle rotating, retracting the strike and allowing for opening of the door.

The Lever
Basically, a lever, with its partner the fulcrum, is used to assist in movement. There are three types of levels, and each is represented in your home in at least one form.

The most recognizable lever has to be the see-saw. I am not certain how many people have see-saws in their yards; they do require space and can be dangerous with younger children. So we'll look elsewhere for examples of the lever.

First, there are the levers you might guess: the bottle opener, the crowbar, and scissors or pliers. The last two are actually called "double levers." And it is ironic I think that these are all tools. Then, there are the ones you might not guess: how about a door, a toilet seat, a broom and even your arm or your jaw. Nowhere near as exciting as the wheel, the level is still tough to imagine living without.

The Pulley
The pulley is probably the most sophisticated of all our simple machines, and it, coincidentally, is the hardest one to provide examples for. Car guys will tell you that pulleys are used in several places in automobile engines. But us house guys have to admit, much less popular in the house.

Unless you have older wood windows, there is a good chance that your house currently contains no pulleys. Pulleys working with rope or chain are employed in extension ladders and can be very helpful when transporting material up several levels of scaffolding.

That's it; that's all I got. I will say, however, that I am currently consulting on a project in Fells Point, Baltimore. We were looking for ways to make it easier to lift heavier things up to the third floor though a narrow attic access. I suggested, in the spirit of the watermen that built those houses, a rope and pulley system. And while my idea got shot down, I am certain it was the inspiration for this piece.

The Wedge
Of this bunch, the wedge might have the most reason to be thankful. Defined as a moveable inclined plane, does it really deserve its own category? All doubts aside, though, it will be treated with the same respect as the rest.

The wedge is used to separate or support two objects. And stopping there, this section is dedicated exclusively to the carpenter's good friend and go-to, the shim, an example of a wedge. Especially if you live in a newer home, and since paired shims have become standard building practice with door and window installations, chances are, your house contains them.

Shims have so many practical uses, it is hard to imagine the end of the examples I could provide. Instead, let's talk briefly about what materials can be used to create a shim. The most common shim is probably the white cedar shake found at your local lumber yard and home center. Industrious types and seasoned carpenters make their own. And for you, there might be more than one occasion when it is a good idea to make one of a scrap piece of pressure-treated lumber. (Note to self: Good idea for a how-to).

Metal shims are manufactured and are used to "shim up" steal beams or retro-fitted lally columns. (Notice it even has its own verb.) Plastic shims can be purchased, and in their diminutive form, can be used for leveling toilets or furniture.

A shim can be made out of something as simple as a scrap piece of cardboard or an old playing card. Carpenters use them to change the angle on their miter saws just that discretely. For me, I find these machines indispensable. When trying to make a small adjustment to a door, a window, or a mitered corner, nothing works better than a piece of cardboard. It is recycling & it is usually free.

The Screw
The screw is a mechanical device that. . . Just kidding. I won't even go into it here. To be quite frank, I feel it desires its own homage. So please hang till I can produce that one.

Six Simple Machines
You may be sitting there scratching your head wondering why you read through this blather. Why even write a piece about simple machines? None of this information is really quite practical. It couldn't be used for a 3rd grader's research report.

Well, I guess I am of the thinking that by understanding the parts, the elemental mechanics of system, it helps in demystifying the system. And while the goal is always a complete system, in its whole, it is best if you know that this system, our house, is equal in some ways only to the handful of, often simple, simple as 2nd grade, parts that come together to assemble it.

Maybe for you, the simple machines may unlock some hidden memory that will get you inspired. Or maybe it might help you work smarter, at least more aware, on your next home project.

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More Moxie:
Wikipedia -- The Free Encyclopedia
St. Joseph's School -- Fullerton