# 16. 3D Printed Pickups

Students will design and print a custom vehicle with functioning wheels.

Standards for Mathematical Practice
CCSS.MATH.PRACTICE.MP1: Make sense of problems and persevere in solving them.
CCSS.MATH.PRACTICE.MP2: Reason abstractly and quantitatively.
CCSS.MATH.PRACTICE.MP3: Construct viable arguments and critique the reasoning of others.
CCSS.MATH.PRACTICE.MP4: Model with mathematics.
CCSS.MATH.PRACTICE.MP5: Use appropriate tools strategically.
CCSS.MATH.PRACTICE.MP6: Attend to precision.
CCSS.MATH.PRACTICE.MP7: Look for and make use of structure.
CCSS.MATH.PRACTICE.MP8: Look for and express regularity in repeated reasoning.

Learning Objectives

• Students will design and print a custom vehicle with functioning wheels.
• Students will work within set parameters to design the best overall vehicle.
• Students will work within set parameters to design the fastest vehicle.

Recommendations
Group Size: 2 to 3 students, depending on how many students are in the class, how many printers are available, and how much time can be allotted for the printing of the vehicles prior to judging and race day.

Class Size: up to 40 students

Materials Required

• At least one computer per group, loaded with SketchUp or Autodesk123D (For this particular lesson, AutoDesk123D is a great tool with its ability to round the edges and customize the design)
• Paper and pencil for drafting
• Airwolf 3D Printer
• Compass
• Ruler
• Protractor (recommended)
• Model cars that students can use as a reference
• 3/32″ aluminum rods for axles
• Super glue to adhere the aluminum rods to the wheels
• LEGO Minifig (or a small character of comparable size)
• Truck-Chassis (STL file)
• Truck-Undercarriage (STL file)

Introduction
Assumptions being made:

• Students have a good understanding of 3D modeling. Prior to incorporating this lesson into a unit, it is recommended that students have had training in 3D design.
• Students have a good understanding of SAE (Imperial) and/or Metric units.
• Students have a good understanding of using a ruler.
• Students have a good understanding of using a compass.

For starters, show this video:

It’s a pretty long clip, so it might be best to pick out 2-3 of the designs that you think would be best for your students (and the most appropriate). This is a Red Bull competition, so it’s attracting some wild designs and might get students thinking further away from the simpler “Jeep”-style vehicle once it comes time to design their own race car.

After the video:

“Wow, doesn’t that look like fun?! Yeah?! Well, I’ve got great news for you – YOU’RE GOING RACING! Not only that, but you’ll need to design your own vehicle!”

After excitement and fear subsides, inform the students that liability insurance is hard to come by and you care about their safety, so they will be sending a LEGO minifig down a course that is designed by you (or hey, the students could design it) in a vehicle that they design and 3D print as a group. This will be slightly less exciting, but a lot more safe and should still get their creative energy funneled into some great ideas.

Next, present students with their challenge:

Design and print a vehicle that is no more than 40mm x 80 mm x 40 mm, can carry a LEGO minifig, and has functioning wheels.

Using only paper, pencil, a straight edge, and a lot of imagination, have students design the 2-dimensional version of their race car. Encourage the use of online searches and hints to designing the fastest and most elaborate vehicle within the constraints provided. However, students must be able to identify measurements for each component of their design (rather than simply drawing something that looks great but can’t be produced with a basic design platform).

The Meat
Within a 3D modeling program, groups will need to design their race car. While we recommend the dimensions be limited to 40mm wide x 80 mm long x 40 mm tall for the sake of plastic conservation and time consumption, it is clearly open to whatever you would like your students to stay within.

Prior to printing, groups must show their design to at least 2 other groups and have them confirm dimensions and review the car for any possible issues that may arise. Once this has been done, groups will send their final .STL file to the instructor and prepare for printing.

When printing, it is advisable to print at least 3 perimeter layers thick, so take this into consideration during the design. Nobody wants to have a car that breaks before it reaches the finish line!

After the design has been printed, students will clean it up and verify all measurements for accuracy with a ruler and a protractor.

Race Day And Judging
Set up a bracket so that every group knows which opponent they will face first, then have students complete the course for the best time with the minifig making it through the entire course. If the minifig falls off, the team is disqualified. Continue racing until you have a champion. Give copious high fives to the winners!

Judging the cars will be a bit more challenging and a lot more subjective. Setting the cars up around class and having classmates vote on categories such as originality, similarity to a car in existence, I would totally buy that if my mom gave me the money, this looks like it’s going to hurt someone, and so on. The students have worked very hard to create their cars, so putting a finishing touch of some voting would be fun.

If possible, bringing in the administrative team and other teachers on campus to vote would give validation to what the students are doing as well.

Discussion

• How did you come up with your design?
• What would you differently after seeing everyone else’s product?
• Does the weight distribution have any significance?
• Why were the faster cars so much faster? What did they do differently?
• How could you have made your car faster?

Each one of these questions can provoke thoughtful responses that are rich in mathematical reasoning.

Just like in a Research and Design lab for major companies, the feedback and reflection on these projects will be the best part. Give students an opportunity to talk within their group and among their classmates to seek advice on improvements. After completing their print, groups will then proceed to:

• Photograph their product for their advertisement (if it is a static ad).
• Reflect on what went well and what they would improve on if they had a chance to print again.
• Create a marketing plan to sell your product to a specific group of people or industry.
• Set a desired cost for the race car, including shipping, based on cost to create the product and cost of shipping.

For the advertisement, students have the option of their medium. Whether it is creating a website, video commercial, radio commercial, magazine ad, billboard, or many others, the key is to be creative in the area that the students are comfortable. During this portion of the project, students will need to work efficiently within a deadline provided by the instructor.

Following the creation, students will showcase their advertisement with the class. Students can vote on which one is the best to use as the model for the school.

Desired Outcomes
A desired outcome is a vehicle that meets the constraints that were set by the instructor – everything else is just a bonus. As long as the vehicle is within the dimensions and have functioning wheels, this should be considered a job well done.

Vroom Vroom!

Content & Instruction Developed by:
John Stevens – Airwolf 3D STEM Consultant
Instructional Coach – Technology
Chaffey Joint Union High School District
CUE Rockstar Faculty & Organizer
Google Certified Teacher
TwitterBlogResourcesAuthor (Flipping 2.0)