Crash Science: Building 3D Printed Crumple Zones

This is one of our favorite projects, and one of our oldest. You, the students, get to learn the basics of parametric 3D modelling, the same CAD technology that's used to design things like car engines (and the STEM Explorer vehicle!), and use your new skills, along with your knowledge of Newton's laws of physics, to build a working crumple zone for the STEM Explorer staff to 3D print and test. You'll not only learn about mass, acceleration, force, and momentum, but also how they apply to real-life safety concerns. Even better, the CAD skills you pick up along the way just might be the beginning of a career in engineering.

The Standards

This project is designed to meet Michigan science standards HS-PS2-1, HS-PS2-2, HS-PS2-3, and HS-ETS1-2, and ISTE standards 1c, 2b, 3d, 4a, 4b, 4c, 4d, 5a, 5b, 5c, 6d, 7a, 7b, 7c, and 7d. For more information, you can read our standards summary document, Michigan's standards document, and the ISTE's standards page.

The Rubric

You can see the rubric that your teacher will use to grade your project here.

The Project

We'll have a lot to get done in the next few weeks. Not only will you be learning CAD modelling and designing your crumple zones from scratch, the STEM Explorer team will also need to manufacture everyone's crumple zone with their 3D printers, and we'll have to test your crumple zone and give you the test data to analyze and interpret.

Important Links

• Onshape's website contains everything you need to do your CAD work, including of course the Onshape application.
• You'll also want to refer to our Onshape tutorial videos to help you learn how to make models. All of these videos are important and useful for your project.
• If you're a teacher, you can get more information about the project from our summary presentation and sign your class up with our signup form.

Step By Step

1. The STEM Explorer team will deliver an introductory lecture, somehow. If we can, we'll come to your school in person and give a brief introduction to the project, but if that's not possible, we'll do the same thing over videoconference, or if worst comes to worst we'll have you watch our video lecture.
2. We'll also try to give you an introduction to parametric 3D CAD modelling in Onshape, usually on the same day as the introductory lecture. If we can't give a live tutorial, either in person or over videoconference, or if you just want to review the material later, you can follow along with our video tutorials.
3. Now the real fun begins. You'll need to collaborate with your teammates to brainstorm a crumple zone idea. When you're done, you should have a rough sketch to turn in to your teacher and to the STEM Explorer staff.
4. Once you've finished your sketch, you can begin modelling your brilliant crumple zone idea in Onshape. You should create one document and then share it with everyone in your team, so that you can work on your design together with your teammates, and with your teacher and the STEM Explorer staff, so we can help you out if you get stuck.
5. When it's time to turn your design in, you should create a final revision of your design in Onshape and tell your teacher and the STEM Explorer staff that it's ready for printing. The STEM Explorer staff will then load your design into the STEM Explorer's 3D printers and set them to work making it. (This part could take a long time, because there will probably be a lot of parts to print, and 3D printers are pretty slow.)
6. When the printer finally finishes your crumple zone, it has to get tested. We connect your crumple zone to a special canister that has an accelerometer mounted inside it, then drop it into our special drop-test chamber from a height of about nine feet. If possible, again, we'll bring all the equipment out to your school and do the test with you live, but if we can't do that, we'll have you watch the testing over videoconference, or as a last resort you'll be able to watch the video of your test when we e-mail it to you along with your accelerometer data.
7. Speaking of e-mails: When we perform the drop tests, we'll be recording slow-motion video of the inside of the drop-test chamber while we drop your crumple zone into it, and the accelerometer inside will be measuring, well, the acceleration that the whole assembly experiences when it impacts the bottom of the chamber. After the testing is complete, we'll send you the slow-motion video and the accelerometer data, so you can analyze them and see how well your crumple zone worked. Your teacher will decide what exactly you do next.