This step by step guide will walk you through the methods that I have found best for making boomerangs on a student's budget.
Step 1: Gathering Supplies
- Safety glasses/ goggles
- Large sheet of paper or cardboard (construction paper, cereal box, or paper grocery bag will do)
- Jig saw
- Electric Drill (preferably corded )
- Sanding Drum
- 1/4 inch Baltic Birch 5-Ply Plywood
Step 2: Designing and Cutting Stencil
Different shapes do act differently. The aerodynamics of a boomerang are entirely dependent on its size, shape and weight properties. Although, usually, I just draw a shape that looks interesting and make it into a boomerang. For the purposes of learning to make a boomerang, consider using an existing design, then you can start drawing your own shapes.
Making a stencil is an easy way to bring your boomerang idea into the full size and is the best way to get the most out of your wood.
There are tons of resources out there for boomerang designs. Here are a few that I found in just a couple minutes of research. I recommend looking at a few of these designs and pick one that looks interesting. It will be easier if you pick one that is symmetric .
World's Great Boomerangs
Master Designs Boomearngs
If you are making a symmetric boomerang, fold the sheet of paper or cardboard in half and draw one half of the shape. Cut the paper while still folded to make the whole stencil.
For unsymmetrical booms, simply draw and cut out the shape you want.
Don't worry if you aren't good at drawing. If you make a mistake, who cares, its just paper, try again until you get the shape you want.
Step 3: Tracing the Blank
I like to cut out 3 or 4 boomerangs out of the plywood in one sitting since I have all the materials set up. It is nice to have multiple stencils ready so that you can piece them together so as to use the minimum amount of wood as possible.
Arrange the stencils on the plywood in such a way that you use the least amount of wood.
Tape the stencils down by rolling pieces of tape and sticking them to the back of the stencil.
Trace the stencil onto the plywood with a pencil (don't use marker or the ink will run into the grain and stain your boomerang.
Step 4: Cutting Out the Blank
Place the plywood on the edge of a work table or outside step, deck or curb. This step will produce a lot of saw dust so do this in a shop or outside.
Make sure the parts you are cutting over hang the surface the plywood is resting on. Plan out the course of your cut. Jig saws cause vibrations in the wood especially if the wood is not supported on the bottom. It's best to cut from the edges inward to avoid large unsupported segments of wood.
Put on safety glasses
Grip the jig saw firmly and rest the skid on the wood for support.
Start the saw before engaging the blade with the wood to avoid kick.
Cut to the outside of the stencil line and move the saw slowly but with some force.
The sharp turns at the tips of the boomerang are the most critical so go slow and stop if you need to.
Jig saws are designed for rather sharp turns while cutting but use your judgement.
To restart cutting , place the blade back into the cut about 1/2 inch behind where you stopped the cut. Start the saw and continue. Do not start the saw when the blade is engaged with the wood.
Step 5: Carving the Airfoils
The reason I use a corded power drill with a sanding drum attachment is I don't have a router table or belt sander. If you have access to these tools, by all means use them, they will save you time.
Determine which side you want to be the top of the boomerang. For symmetrical boomerangs, it doesn't really matter.
Determine the leading edge and trailing edge of each arm. This will depend on whether you are making a left handed or right handed boomerang. If you are right handed, you should make a right handed boomerang and lefties, make a leftie boomerang.
Right handed boomerangs spin counterclockwise
Left handed boomerangs spin clockwise
The leading edge is the front of the arm will be more rounded and blunt . This side rushes into the wind.
The trailing edge is the back side of the arm and will be more tapered . This side trails behind the leading edge.
Refer to the right handed boomerang in the pictures above. A leftie boomerang will be the mirror image.
The second diagram in the pictures below is the cross section of one arm with the leading edge to the left.
Sand down 2 out of the 5 layers of the plywood to about a 35 degree angle on the top and bottom of the leading edge.
Sand down 3 out of the 5 layers to about 20 degrees on the top of the trailing edge and one layer on the bottom to take off the sharp edge.
Repeat steps 2 and 3 for each arm of the boomerang.
Step 6: Decorating Your Boomerang
Once you are confident, consider using a clear spar urethane for water protection. If you want some color, use spray paint. I like to paint my boomerangs bright colors so I can spot them in if they get lost in tall grass.
Warning: Adding any sort of coating, varnish or paint will add weight to the boomerang and will change its flight properties. You can't be sure how it will change until you test it.
Step 7: Throwing Your Boomerang
My advice is
1) Stand in a big field, about the size of a baseball field, facing directly into the wind. Tear some leaves of grass and toss them into the air to see which way the wind is blowing.
2) Hold the boomerang on the wing tip of either wing between thumb and fore finger. The top of the boomerang should be on the side with your thumb
3) Imagine you are standing at home plate of a baseball diamond (see the diagram for a right handed thrower below). The wind is coming straight from the pitcher towards you. If you are a right handed person, imagine the boomerang is a tomahawk and you have a beef with the first base men, If you are left-handed, your beef is with the third base men.
4) Now, Imagine two huge panes of glass extending lengthwise from you to your imaginary enemy baseball player. Between the two sheets of glass, there is only enough room to fit the thickness of the boomerang. Throw the rang between the glass sheets directly at your foe's head with enough force to knock them out. Most beginners make the mistake of throwing the boomerang too horizontally and not hard enough. When you let go, the boomerang should be between 80 and 90 degrees to the ground.
5) The boomerang should curve towards second base while rising and flattening out (starting to spin more horizontally like a Frisbee). It will come back to you more or less from the direction of the third basemen if you are right handed or the first base men if you are left handed. Ideally, by the time it returns, the boomerang will have rotated its axis of spin to the horizontal (like a helicopter) and will slowly sink to the ground (that is, unless you catch it).