June 5, 2014
3D Printing the Moon
A few years ago I had the opportunity to teach 3rd grade. One of my favorite units to teach was all about the Moon with an emphasis on understanding the phases of the Moon. Teaching the phases of the Moon is a perfect example of when a good model is necessary. My students and I made many observations of the Moon, we saw a diagram in the book, and we performed experiments with an overhead projector and a cup however, it was hard to really wrap our heads around why we see different parts of the Moon at different times of the month.
We decided to take the diagram in the book and make it into a 3D representation on a bulletin board. I didn’t have a 3D printer back then so I decided to use ping pong balls to represent the Moon. We had done a Geography lesson earlier in the year where we created paper mache globes. I used my teacher example sphere to represent the Earth. I cut it in half and tacked it to the center of the board. The students painted half of their ping pong balls black to represent the dark side of the moon and we glued those to the board around the Earth. Next to each ping pong ball we posted a picture of what that phase of the Moon looks like in relation to the Earth and the Sun.
The final board looked great, but still needed one more Education Technology touch to really make the learning happen. I was able to take a web cam and hold it on the Earth. Pointing the camera at the ping pong balls the image (displayed on the computer) clearly showed an image of the correct phase of the moon. It made it easier to understand how our perspective from Earth as well as the position of the Moon and the Sun is why we see different phases of the Moon.
This year, I had the opportunity to work with another teacher who teaches 3rd grade. She was teaching the Phases of the Moon Unit, and I shared with her what I had done. She was interested in teaching this lesson and with the 3D printer we had the capability of printing models of the moon instead of ping pong balls to further illustrate how the Moon looks from space. She went to work on teaching them the background information. They performed some really interesting experiments, then I came in and had a discussion about the class creating a bulletin board like the one I had done in my previous class. I gave them directions to make a plan in their journals.
I came back a few days later and we reviewed their diagrams. They explained the diagrams to me and shared why they had chosen to represent them in the way that they had. It was great to see a variety of ideas. Each of them had great reasons why they drew the diagrams the way they did. It was easy to tell that they had a good understanding of how the phases of the Moon work. After some discussion we settled on a collective design for the board. The kids went to work on painting the Earth, and I showed them how to find a model of the Moon on Thingiverse. (We didn’t have the time to design our own.)
I was able to show them the process of downloading the files and loading into our Afinia printing program. They also got to see how the printer works. They were very intrigued and excited to see it work. I ended up printing 8 moons total. I did a couple of them at home and my son had good time pretending he was Gru from Despicable Me who shrunk the Moon to steal it.
The students used Sharpies to shade the dark side of the moon, they used hot glue to connect push pins to the bottom of their moons, and then we stuck their moons on the bulletin board that they had created. The next step was to mirror an iPad to the projector and put the iPad on the Earth to represent our perspective. We were able to perfectly capture the phases of the Moon and we realized that we had some of the images in the wrong places. After some adjustments, the final result was a perfectly functioning model of why we see the phases of the Moon in every day life.