Young Engineers of Today Spring Lab 5: PVC Trebuchet Part 2

Monday and Tuesday night were a blur of excitement, cheering, design genius, design flaws, and more. We had our 5th lab for Young Engineers of Today Monday and Tuesday night. What we attempted to accomplish was both daunting and fantastic.

This lab was part 2 of our PVC trebuchet project. In our 4th lab we started the drafting, prototyping, and making of our trebuchets. This lab our goal was to finish.

Our agenda for the lab was as follows

1. Recap our 4th lab and what we learned

2. Discuss future labs and where we are headed

3. Finish building trebuchets

4. Make launching mechanism and projectile

5. Test out and dial in our trebuchets

6. Come back and build a second one so each student can take one home

Students worked in pairs when designing the trebuchets. For many this was their first time measuring, drafting, cutting, using saws, assembling PVC, and understanding the science to projectiles. I covered most of this during our lab 4 so I won’t repeat it all. Going back to the goals of the night we had a lot to cover.

The students were amazing. They instantly got back to work on their trebuchets to fine tune everything and remember where they left off. We have lab every two weeks so this can be a problem with remembering. They went right to work making final cuts, tweaking their design, and ensuring it was ready to go. They all added the hanger piece to add to the projectile, assembled the PVC cap/duct tape/string projectile and about 35 minutes later we were all ready to go test. I did not have them start making the second trebuchet because if their first design did not work, then there is no point to build another.

One night we tested in the gym and the second lab students had to go outside to test. I thought testing would be a breeze, but I was wrong. Once again I am shocked and reminded why this program is so vital for student thinking and problem solving. They are masters of understanding science, formulas, games, apps, and simulations. However, when it comes to the real world and actually making and doing they struggle. Once again I was asked questions like I cannot measure 42 inches with a yardstick. How do I get to 42 inches? Simple little tips and ideas that we take for granted come to light when making ideas come to life.

I gave them advice for factors to adjust the hanger piece, the throw arm length, the amount of force used(we used human force as we did not have enough barbells), and projectile position. It took about 10-15 minutes for them to finally get a good launch.

When the projectile smacked the ground in front of them, fell off, shot backward, or shot upwards they froze. I think they thought it would work perfectly. They would look at me hoping I would fix it. I gave them suggestions and had them try again. And when it worked you could just see the happiness and excitement. There was such a buzz for learning that I cannot describe it in words. You could feel it in the air. Then once it worked once they started tweaking to find out how to go farther, higher, and to be the best!

What I was most impressed with more than anything was how they helped one another. A group would struggle and another student would come over to help. They were sharing their learning, their tips, ideas and just promoting the whole DIT(Do It Together) mentality of making and engineering.

After tweaking and making sure they all worked, we went back to the room and started to make the second copy. It is important every student takes home their learning and projects. We want them to keep learning at home beyond the lab. We want them taking pictures and videos of their learning. They went to work making a ton of new cuts and measuring. They also strengthened the joints with duct tape. We did not glue in case the trebuchets would not fit in the cars.

All in all this was another great lab. This semester I have really fallen in love with the class and these students. I see so many great ideas and moments of learning. Some of these students have really grown up and come a long way in a few months.

Last, I want to share this other video of some of the test launches. The reason I am showing this is to clear the air. First, none of these were taped or glued as we were simply testing at this time with different arms and designs. Once they got things dialed in they glued and taped. Second, I want the world to see that these student worked vigorously to make it work. How often in schools do we give kids one chance? There were failures, setbacks, parts falling off, failed launches and yet the students persevered until we were rocking launches of 50 – 100 feet with a very lightweight projectile. I could not be more proud. I share this so you can see the determination students can have when they are invested in the learning. Also, you can hear and see the excitement for their learning as well!

Now, I just need to finish my trebuchet which is going to be launched from my phone using littleBits. I just need more time in the day.

In our next lab we will begin soldering and programming robotic hands and start 3D printing our checker pieces where we will make molds of our designs.

Stay tuned!

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