When I asked boomerang ninja Logan Broadbent to visit our local high school where I volunteer, he wowed us with his signature stunts that have fueled his videos to tens of millions of views, but he spent the most time in our design and manufacturing class showing us the science that makes a boomerang work and strategies to develop our own designs.
After lots of iterations and some evolutionary dead-ends, we present our World Wide Boomerang. I’ve made it successfully with middle school and high school classes, and it fits into one class period. It’s safe (doesn’t hurt people or break windows), costs pennies, flies in a small yard, is adjustable for advanced flying, and yes, really comes back. It’s an intuitive way to experience why the airfoil shape is so essential to aviation.
1. Make the airfoil sleeves
The airfoils are made from file folder material that we’ll fold and tape to form sleeves, which slide onto the spars. Cut a 5-1/8” × 2-3/8” card from the file folder (or cut out and tape the template to the folder as a guide).
Tape the long edge of the card to the long edge of a tongue depressor. With the taped side facing down, fold the paper over once at the tape, then fold a second time at the paper and make a hard crease. Remove the stick from the tape, but leave the tape on the paper.
Reposition the stick into the valley of the second fold. Fold and tape the edge of the paper over the tongue depressor and onto the other part of the paper to make a sleeve that easily slides off the stick — and it’s a perfect airfoil! Make two more and set them aside.
2. Glue the spars
Tape the first tongue depressor spar to the pattern. Apply hot glue to the hub and quickly line up another spar with the pattern lines and overlapping the first, then push down before the glue cools. Do it again for the third spar. The spars give the boomerang its strength.
3. Add dihedral
Our boomerang needs a little bit of dihedral — that is, an upward slope of the wings. In the case of our boomerang the dihedral is subtle enough that you can’t necessarily see it, but you can test for. Spin the assembly on a flat surface, then flip it over and spin again. Choose the side that spins more easily and mark the top of the hub with a “T”. If both sides spin about the same, choose a side and gently bend the spars up into a curl until it spins freely. The side with the T will always face toward you when you throw.
4. Right-Handed or Left-Handed?
For right-handed throwers, start with the T face up and a spar pointing toward you. Slide an airfoil onto the spar so the tape seam faces down and the hole for the stick is on your right side. For left-handed throwers, the hole goes on the left side. Repeat for the other spars.
Tape them in place and you’re ready to fly!
Boomerangs generate lift like helicopters, but by throwing them almost vertically, much of the lift is sideways. That’s what makes them come back (along with some gyroscopic precession for the curve, which also flattens out the boomerang at the end for a gentle hover down into your hands).
- Remember that the T faces toward you when you throw.
- Hold a wingtip and throw it — with lots of spin — angled at about 1 o’clock if you’re right handed or 11 o’clock for lefties.
- Throw it straight ahead. Boomerangs have their own lift, so you do not need to throw it upward.
- Bend the spars for more dihedral to fly higher and hover down gently. If it’s not coming back, gently twisting the wings so the blunt end is higher (aka increasing the “angle of attack”) will increase lift and make it turn back.