With one hour of work, you can have a boomerang that actually comes back. It's like magic.

This design was inspired by a book I used to check out from the library, read and re-read when I was a kid. It's called Boomerangs: How to Make and Throw Them , and it was pretty great. The author would apparently make boomerangs that he could throw and then catch with his eyes closed. He would also paint them and get birds to chase them. Every time I've made one of his designs, it's been very successful. This instructable shows my version of what I remember being my favorite design: a simple cross-type boomerang made from thin, beveled pieces of wood with a slight bend. Dimensions aren't critical: the design is robust enough that it seems to work well as long as you get the basic idea right and the bends in the right direction.

What you need:

Full Version:

An 18" 2x4, (or 2x6, 2x8, 2x10... etc).
Wood glue
A table saw
A sander
A microwave

Poor-Man's Version:

Two 18" paint stirring sticks (from home depot)
A pocket knife
A bolt and nut (or wood glue)
A candle

I made it at TechShop (techshop.ws)

Step 1: Cut Two Thin Strips of Wood

Full Version:

Cut two strips from your piece of wood. Final strip dimensions should be ~ 2 inch wide, 1/8-1/4 inch thick, and 18-24 inches long.

If you're using a 2xsomething, put your table saw at a 45 degree angle (increases strip width from 1.5 inches to 2.1 inches). Alternatively, you could rotate the wood 90 degrees and cut very wide strips (3.5" for 2x4, for example), then cut those strips down to the size you want.

Poor-Man's Version:

Paint stirring sticks = wooden strips. They are probably too narrow, but they'll still work pretty well.

Step 2: Round the Strip Edges

Full Version:

You can do this with a band-saw, or you can do it with a sander.

Poor-Man's Version:

You can do this with a pocket knife*.

_{*If you're in a pinch, (if, for example, you are trying to make a boomerang so that you can hunt for food in a zombie-infested apocalyptic future), you can round the edges by scraping them on a sidewalk.}

NOTE: You only need two strips. I'm showing four because I made two boomerangs (one with thicker strips, one with thinner strips).

Step 3: Bevel the Edges

Bevel the edges of your strips. You want one side of the strip to be flat, and the other side to be round. Like a long, thin semi-circle, or a boat turned upside-down, or an effigy mound.

Full Version:

Do it with a bench-top belt sander in 5-10 minutes.

Poor-Man's Version:

Do it with a pocket-knife*. Go slow so you don't catch the grain and carve off a giant chunk**.

_{*Again, there's always the sidewalk.
**I speak from experience.}

Step 4: Find the Center of Balance

Balance each piece on a suitably sharp, stable edge (for example, a knife-edge, a pencil, a ruler, a rib bone). Mark a line when you achieve balance (with the strip, not with life). The center of balance will not always be in the exact middle, depending on how symmetrically you did the bevelling.

Full Version:

Use a pencil.

Poor-Man's Version:

If you don't even have a pencil, why do you want a boomerang? Set your goals lower. Start with getting a pencil.

But if you insist, you could scratch a line with your fingernail, or with your teeth. Or with the sidewalk.

Step 5: Glue the Strips Together

There is some debate on this step. Some people like to glue the strips together in an "X" shape. Others prefer a "+" shape. I won't presume to tell you which is better. Do what your inner boomerang tells you. Just make sure to line up the centers of balance, and you'll be ok.

Full Version:

Use wood glue. This stuff is strong. If you glue two Popsicle sticks together with a drop of wood glue, wait 24 hours, and then try to pull them apart, you will snap the Popsicle sticks before you break the glue joint*.

Poor-Man's Version:

Drill a hole and use a bolt and nut to join the two pieces together. OK, I know this isn't necessarily easier, but if you don't want to wait for the glue to dry (i.e. if you're a lazy man, soon to be a poor man, see Proverbs 6:9), then it will work. In fact, I think I remember the guy in the book using a bolt because he liked to catch the boomerang by the bolt**.

_{*Again, speaking from experience. I was about 10 years old at the time.}
_{**I am in no way condoning the catching of whirling bolts, especially with your eyes. Safety first :).}

Step 6: Bend the Strips Upward (the Concept)

This is the most tricky step, and it's not that tricky. All you want to do is bend the boomerang strips upwards (towards the curved sides). Just a little bit of a bend is ok. The trick is getting the bend to stay, and to do that, you need to:

Get the bending portion hot
Bend it
Let it cool while bent

Bend at about the 1/3 and 2/3 points of each strip.

More detail in the following two steps.

Step 7: Bend the Strips Upward (Method 1)

(Animated GIF: Click to View)

This is the method recommended by the author, if I remember correctly. It sometimes leads to burnt wood, and doesn't always work very well. But if you don't have a microwave, then you've got to do what you've got to do.

Use a candle to apply heat to the section you want to bend (using a little bit of water helps).
Bend, using a small object to prop up one end of the strip.
Hold until the wood has cooled.

Step 8: Bend the Strips Upward (Method 2)

(Animated GIF: Click to View)

This is my new preferred method. You'll need a microwave.

Wet the portion you want to bend
Microwave for about 15 seconds
Bend
Keep bent until the wood has cooled

Step 9: Throw It

The boomerang turns toward the beveled side.

Right-Handed Version:

Hold the boomerang upright, in your right hand, like you would hold a throwing knife (or a pack of cards, if you've never held a throwing knife). The curved / beveled side should be facing your left and resting against your thumb.
Throw. Just like a throwing knife, except flick your wrist to get as much spin as possible.
The boomerang will curve to the left, then turn horizontal and float back to you.
Pancake catch it (like a frisbee)

Left-Handed Version:

Use your left hand.

Here's a video of me testing mine out. The one with the thinner strips did better in this tiny park. I think the thicker one will be more fun when I find some more space.