3D Printed CO2 Car - Part Two Race Time!

thingiverse

This is part two of the 3D Printed CO2 Car project posted here: http://www.thingiverse.com/thing:1594511 This lesson assumes that you've completed one car. Hopefully you were able to get a timer and have some races. In this part I will discuss redesigning for improved time, redesign for improved stability and testing weight change vs speed ratio. If you made it this far you've already learned how long it can take to print one car. The first time I did this lesson I chose to only reprint the wheels. I talked to my students about the options in wheel redesign. Mostly they made the wheels lighter using the previously taught "hole" feature in Tinkercad. If you have the time to remake the cars then there is plenty that can be done for redesigning. Print Settings Printer Brand: MakerBot Printer: MakerBot Replicator (5th Generation) Rafts: Yes Supports: No Resolution: 0.3 Infill: 10% Notes: You can test different infills to produce more weight too but 10% works well enough. Most wheel take about 45 minutes to print. Standards NGSS Overview and Background Objectives Students will redesign their CO2 car while applying math skills on order to measure their car's progress. Standards Stem Standards: Standard 1: Analysis, Inquiry, and Design Students will use mathematical analysis, scientific inquiry, and engineering design, as appropriate, to pose questions, seek answers, and develop solutions. Standard 3: Mathematics (Revised 2005) Students will understand the concepts of and become proficient with the skills of mathematics; communicate and reason mathematically; become problem solvers by using appropriate tools and strategies; through the integrated study of number sense and operations, algebra, geometry, measurement, and statistics and probability. Standard 6: Interconnectedness: Common Themes Students will understand the relationships and common themes that connect mathematics, science, and technology and apply the themes to these and other areas of learning. Lesson Plan and Activity There is a lot that can go with this lesson so I'll try to break it up into specific categories that can be explored. Redesign/Weight Reduction: Using the hole tool you can have students redesign their wheels in two different ways. They can make the wheel thicker/thinner and/or reduce weight. However if the change the diameter of the wheel then the launcher will not align with the air tube. It's better to change one parameter at a time in order to keep things simple. This is where the timer comes in handy. Using the timer race times can be compared to race times of car after redesign. This is also a great way to teach students about place value of numbers to the right of the decimal point. You can compare race times of different designs and different cars which allow students to practice decimal value knowledge through comparison in a real world setting. Many sports use this as a measure including Nascar, Olympics and horse racing. Calculations can come in handy for the high grades. Teaching students how to use formulas such as "Speed = Distance ÷ Time" in areal world application can have a huge impact on information retention. Here's a link to a calculation website: http://www.machinehead-software.co.uk/bike/speed_distance_time_calc.html