Here are two ways to build a LEGO contraption that launches paper airplanes! This fun LEGO building challenge combines STEM learning and play.
This would be a fun building challenge for a LEGO club or a STEM club!
LEGO Paper Airplane Launcher #1:
One day, Aidan came up with the idea of building a LEGO paper airplane launcher using the pull-back motor that came with a Technic race car set. He spent time over several days perfecting his design. The final launcher only launches the paper airplane about 4 feet, but I’m sharing this idea with you anyway because it’s a really neat engineering challenge!
If you don’t have the pull-back engine needed to build this project, you can get one inexpensively on Brick Link.
Besides some basic bricks and some Technic bricks (with holes), you will need:
- A pull-back motor
- Gears – We used 16 tooth gears and 40 tooth gears
- Technic axles – 12 studs long
- Large wheels – We used these wheels (30.4 mm x 20 mm) with these tires.
The base of the airplane launcher has two large gears and two small gears. The motor will connect to one of the large gears. The motor spins the large gear, which spins one of the small gears and the other large gear. The second large gear spins the second small gear. The two small gears need long rods in them – these will turn the wheels that actually launch the plane.
Attach the motor to the rod sticking out of the large gear. The second rod in the motor is just for stability.
Add another layer of bricks and then attach the wheels to the Technic axles. The axles are x shaped and fit into the x shaped opening in the wheel. The wheels should turn when the axles turn.
Aidan built a tool to wind the launcher out of another Technic axle and a gear. To wind it, stick the Technic axle into the orange hole in the motor and turn. You’ll need to hold down the other large gear to keep it from unwinding as you wind it!
The paper airplane launcher works by using energy from the wheels to push the plane forward. You’ll also need just the right amount of friction between the wheels and the plane. To get the launcher to work, you’ll need to experiment with:
- The tilt of the launcher.
- The distance between the wheels – Aidan added the rubber band to make the gap smaller.
- The width of the paper airplane. Try adding more layers of paper to get a tight fit with the wheels.
Aidan’s best version of the launcher only launched the plane 3-4 feet. But I thought it was pretty amazing that he could design something out of Legos that would even launch a plane at all! This is a great engineering challenge for kids.
After winding the launcher, hold down the second large gear while you insert the plane. Then let go!
LEGO Paper Airplane Launcher #2
Here’s a simpler way to create a LEGO paper airplane launcher, and it launches the plane much farther as well. (But there are fewer engineering considerations involved!)
This is the basic design. We used a large rubber band wrapped around this LEGO frame. The frame is not attached to the baseplate because Aidan wanted it to have a tilt, but I would probably make it flat and attach it to the baseplate for stability.
Bend a paper clip to create a hook shape and tape this to the paper airplane.
Put the hook around the rubber band and pull back on the paper airplane.
Then let go, and the paper airplane will fly across the room!
We have another post that shows how to build this type of paper airplane launcher with a board and two nails.
This project would be perfect for a LEGO club or STEM club! Need more STEM ideas? You can check out more ideas here: STEM Activities.