Introduction to Engineering With 6th Graders

A teacher at my school is taking a training in preparation for the new science core rollout in our state. She asked me if I knew of an easy to use program that kids could use on the computer to design things. I shared Tinkercad with her but then asked if I could actually come into her class and teach an engineering unit that would incorporate 3D design with printing actual objects on a 3D printer. She gave me permission, so this blog post covers what I taught her class during the first week.

To peak their interest, the first thing I did was place the 3D printer on a cart and wheel it into the classroom. I invited the students to come stand around it and we discussed how 3D printers work. I was surprised that none of the students had seen one before and so I took a little extra time with this part. I showed them the different motors and how the nozzle melts the filament. I passed around a piece of filament so each student could feel its strength and flexibility. I showed them how to load the filament, and started printing a small object.

While the object was printing, I used a slideshow to introduce the unit. Here is a link to the Google Slide I used: https://docs.google.com/presentation/d/1vHGHjTYRHlw8GNidb7C9BJ_XExdvTbuqAgrKfc6gdvs/edit?usp=sharing.

The point of the slideshow was to explain that the 21st Century skills of Critical Thinking, Creativity, Collaboration, and Communication are crucial to being successful. The collaboration and communication skill for today's lesson was "Wait until others are done speaking before talking." I talked about how they were going to do an engineering project that would have them practice those skills.

I used this image to introduce the engineering cycle:

The task I presented them was this: We have a park beside our school that has a creek run through it. There are a couple of bridges across the creek, but people have been calling the city to complain that a city worker keeps driving a lawn mower across the bridges while kids are playing there. The city would like this class to design a bridge that could be used to drive a lawn mower from one side of the creek to the other.

I shared this picture as the basis for their bridge:

I also printed 6 copies of the bridge template we will use to test their designs on Week 4 (note I also made a simple flat piece you can see at the bottom of the picture):

The rules for their design were:

• Bridge can only rest on the surfaces highlighted in yellow
• Gravity is the only thing to hold bridge in place (no tape, glue, screws, paint, etc.)
• No more than 25% Infill
• Must use 7 meters or less of filament
• A wheel must be able to “roll” across bridge
• The width of the bridge surface cannot be skinnier than the bridge template

With the engineering cycle in mind, I followed these steps:

1. I gave them 30 seconds of silent thinking time
2. Then they got out paper and pencils and had two minutes to draw the ideas they came up with
3. Then I reminded them about the focus of not interrupting others and asked them to take turns and share their designs with others
4. I passed out a 3D printed bridge template to each group
5. Then I passed out cardboard and rulers and asked them to build their first prototype

I was surprised that the students had such a hard time using the plastic templates I passed out for building their prototypes. Most of the groups spent the majority of the time using the largest pieces of cardboard available to make huge designs. I tried letting them work through this on their own, but when there 10 minutes left in class, I mentioned to them that it might be a good idea to build their prototypes directly onto the bridge template.

At the end of the day I asked them to raise their hands if someone in their group interrupted them during the activity. About 5 of them indicated that they had been interrupted so we'll have to keep practicing that skill. My plan for next week is to reinforce that social skill and introduce the concept of using consensus to make decisions.

I also showed the what the printer had made: http://www.thingiverse.com/thing:375778