Mechanisms and Simple Machines: How to Make a Gearbox with Moving Parts

You can learn about mechanisms with these gearboxes made from just cardboard, sticks and foam!

At our engineering Summer Camp in NYC, we prototyped projects focused on helping children to better understand how simple machines and mechanisms work together to create movements. Throughout the week, our campers built gearboxes, took apart (and tried to reassemble!) toys with moving parts and presented shadow plays with their gearboxes to parents. In this post, I’ll provide directions for making your own gearbox at home!

To Make a Gearbox

This is a great activity for teaching children about the mechanisms needed to create desired movements. Here are the instructions for how we made ours–feels free to use these as general guidelines or as a starting point.

What You’ll Need

Cardboard box with front and back sides cutout
Foam (we used 1/8th inch) for mechanisms
Bamboo skewers or small wooden dowels
Tape
Colored paper (or anything else you’d like to make your characters from)
Hot glue

Steps to Assemble Your Gearbox

1) Pick a box you’d like to use, cut out the front and back portions
–It should large enough to work in, but smaller than the length of your dowel/skewer

2) Research different types of mechanisms and movements, you can begin by checking out this site.

3) Create the gears you’d like by cutting the foam into circles.

–A more circular gear creates more uniform movement

4) Create the gear system, push the skewers through the foam gears, and poke them through the cardboard so the gears can rub against each other.

–-Make sure the gears are carefully placed so they touch each other with some force

5) Create your character for the top of the box. The character is what the mechanisms will work to move.

6) Connect skewers from the gears, through the box (not connected to the box) to your characters.

–You should now have a gearbox with moving mechanisms!

Gearbox Redesign Ideas

Here are some things you can try at home to continue learning about mechanisms and developing your gearboxes.

Try changing things about the gears:

You can cut the gears roughly or place rubberbands around them to increase friction.
Try cutting gears in non circles, what works, and what changes?

Create different gear systems:

Try using more gears, different sizes, and different orientations
What happens when the skewer isn’t through the center?

Common Problems When Making Gearboxes

If your gearbox isn’t working at well as you’d like, try these ideas.

The gears are touching each other but don’t push each other:

Try moving them together even closer
Try putting a rubber band around the gear

The gears slide on the skewer, getting out of place:

You can attach the gear to the skewer with glue, tape, or rubberbands

The gears flop or bend off to the side:

Reinforce the gears with heavy weight paper attached on both sides

Now That Your Design is Done

Share it with us! Submit it here for feedback and ideas for redesign from our engineers. We’d love to hear about your process and what you thought was meaningful.