Ten Snowmen Leaping (zoetrope Powered by Micro:bit)

Make a zoetrope to create an animation of snowmen leaping!

A drum with sequential stills facing inward around the circumference. Peer through equally spaced slots to the images on the opposite wall. As the drum spins, the slits provide a broken view of the drawings, creating an illusion of a moving image.

*Some mathematics involved in the making process.

1 x micro:bit
1 x breakout board
1 x continuous servo
1 x battery pack
2 x AAA batteries

Making
2 x black A4 paper
Cardboard
Scissors
Penknives
Coloured Markers
Double-sided tape
Scotch tape

To Print
1 x base template
1 x animation strip template
1 x side section template

Decide how big the zoetrope will be. This will depend on the materials you have available. The most important dimension is the diameter of the drum. This diameter will help you figure out the circumference or perimeter of the circle.

Use this equation to figure out your circumference:
"C = D x pi" (where C is the circumference and D is the diameter).

In the reference PDF, the diameter of our circle is 18cm / 7 inches. You can print that out, trace it over cardboard, and cut that out and poke a hole at the center of the cardboard circle.

We need to calculate the width of each frame now.

Use this equation to figure out your width::

“w = (2 x pi x r) divided by f” (where w is the width of each image, r is the radius of the circle, and f is the number of frames).

For example, our zoetrope: 4.71 = (2 x 3.14 x 9) divided by 12; 4.71 cm or 1.85 inches.
You can print out of reference PDF and cut out the strips, add in your drawings and connect the 3 strips using double-sided tape but do not connect the ends just yet.

If you decide to add more frames, please do it in the multiples of 12, where the minimum frames needed for a zoetrope is 12 and re-do your calculates with the formula.

The sidewalls should be at around twice the height of the frame. This provides space at the bottom for the strip of images, and the slots at the top.

In our reference file here, the height of the walls is 9.6 cm / 3.8 inches, and you will need to cut 4 of these out. Connect the tabs of the 4 side section to make a long strip and do not close the two ends yet.

We used black paper to emphasize the contrast of the animation strip.

Remember to test the size of the wall and the size of the image strip by temporarily curving the wall into a drum and placing a strip inside. The strip should fit perfectly into the drum, without having to use adhesive.

Once you have checked that the sidewalls and frames fit perfectly, paste the frames to the sidewalls and the sidewalls to the base.

We find that it's easier to tape the sides down section by section

*Ensure the slots are on top!

If you have seen our carousel tutorial, this step will be familiar.

Connect the servo to the micro:bit as shown in the picture, we used P1 on the breakout board.

Write a simple start/stop command on makecode and upload that to the micro:bit.

You can also refer to our screenshot if you're lost. Button A starts the servo spinning in a clockwise direction while Button B stops the servo from spinning.

The hole we made in Step 1 will help us locate the center, attach the servo to the bottom on the zeotrope. Plug-in the battery pack, press button A and watch it spin away and your drawing come to live!