On the first day of our Engineering Unit, we tell our students that their challenge is to figure out how to launch a pompom into the air. We have lots of materials on the table, and we have three prototypes to show them that they can test out. They can choose to build one of those, or create any other design from the materials available.

The supplies we provide: plastic spoons, rubber bands, TP rolls, balloons, craft sticks or clothespins, snow cone cups or paper to roll into a cone shape, straws, scissors, tape.

Here are our three prototypes:

Spoon on a Clothespin

Take a plastic spoon. Insert it into an old-fashioned clothespin, tape it tightly. (Or tape the spoon too a craft stick. The goal is to make the handle longer for more leverage.) To use: put a pompom in the spoon. Hold it in place with one hand while you hold the clothespin in front of you with the spoon at top, facing away from you. Pull the spoon back, and let go.

You could also offer craft stick catapults as an option. The only reason we don’t is because we’ll be building them a few weeks later in our Levers class.

Balloon Poppers (aka Marshmallow Shooters)

Just tie a balloon (no need to inflate it), then cut off the rounded end and stretch that opening over the end of a toilet paper tube. You can stop there, or if you find your balloon is pulling off of the tube when you pull on it, just tape it or rubber band it in place.

To use: Hold it with the open end of the tube facing up. Load it with a marshmallow, pompom or whatever, then pull down on the balloon knot and release to launch it. The pompom will likely hit the ceiling.

Modification: You could also use the rounded end of the balloon instead… it’s just easier to pull down the knot than the rounded part.

Variations – instead of using a toilet paper tube… On Coffee Cups and Crayons, she uses a cake pop container.  Paging Fun Mums uses a plastic cup with the bottom cut off.  Frogs and Snails uses a pool noodle, which would be good for little ones who might crush the toilet paper tube by holding too tight.

Pompom Puffers

Make a small paper cone.* Tape to a bendy straw. Then you set a pompom in the cone, and blow through the straw, trying to keep the pompom afloat in the air over the cone without escaping.

*Here is a PDF with my directions and a template for the circle. Or, if you have Sno-Cone Cups, you can use those instead of building a cone – you just snip off the very tip of the cone, then tape it on the straw.

Take it to the next level

Once a child has built a successful launcher, we challenge them to refine it. We offer some goals: How could you make it launch the ball further? Can you hit that target – if not, how could you make your launcher more accurate? Could you make it launch more than one pompom at a time? They can choose to tinker and refine as much as they want to. This is a great chance to practice the engineering process.