Motor Car Science Lesson

thingiverse

A standard science lesson has been converted to one with a 3D design component. The students build a car from found resources and and a small DC motor. They race the cars to see who has the design that reaches the finish line first. The change is the upgrade to 3D printed wheels and pulleys. Print Settings Printer Brand: MakerBot Printer: MakerBot Replicator (5th Generation) Rafts: Doesn't Matter Supports: No Resolution: 0.1 Infill: 100 Notes: These parts are small and take a lot of wear on the motors, so I used 100% infill. Post-Printing For this project, I printed a variety of wheels and pulleys for the students to choose from. In the future, students will be required to design their own parts. How I Designed This This lesson is a remix of a lesson used for years in the classroom. Standards NGSS Overview and Background Every year after completing a science unit on how electric motors work, the class takes what they have learned and creates a small car using cardboard, straws and bottle caps. They add a motor and a rubber band to power the car. The project culminates with a car race in the gym. The best design is the one that gets to the finish line (half-court) first. Previously all students used bottle caps for their wheels. This caused cars to not drive straight or very fast. This year students were given the option of designing parts to be printed on the 3D printer. Lesson Plan and Activity Lesson on Electric Motors Attached is a lesson from IEEE on how electric motors work and how to build one. This is the first step in the car building process. https://www.ieee.org/contrib/groups/public/@ieee/@web/@org/@educ/documents/file/20041417.pdf Building the Car Taken from: http://www.miniscience.com/kits/CAR_ELEC/ Electric Car Introduction: Making an electric car is a mechanical engineering challenge often used as a competition for students from 5th grade up. An electric car is driven by a DC electric motor, powered by one or two batteries. Transmission of force from the motor to the car axle is accomplished using two pulleys and one rubber band acting as a belt. A simple switch made of a paper clip is used to connect or disconnect the circuit. Wheels are made of larger pulleys with rubber rings as tires. The car chassis is made of cardboard, reinforced by drinking straws. For our cars, students designed the wheels and the pulleys using tinkercad.com. They needed to decide how big they wanted each to be. They needed to take into account the inertia that needed to be overcome, and the weight the motor must move. With this project students can explore: A simple propulsion method Basic gluing techniques and design concepts Concept of stored chemical energy energy and converting it to mechanical energy A simple electric circuit During construction of the electric vehicle, students can experiment and comprehend methods of power transfer, using glue, measurement, making a simple electric circuit . It is up to the teacher to make sure this background information is provided to students in some manner. Background Before invention of gas engines, cars were pulled by horses or other animals. Now gas burning engines are the most popular drive in cars. There are concerns about the air pollutions caused by gas engines and electric cars are entering the market in a fast pace. Electric cars rely the electrical energy stored in batteries, so they will not cause any air pollution. Because of the limited amount of electricity stored in batteries, electric cars must be made very light so they can transfer a longer distance with a limited amount of energy. Assembly Procedure 1.Before students construct their vehicles, they will make a complete blueprint of their design to scale..They must get approval of their design before they begin building. After the design is approved, a list of needed materials is made, and the designs requiring 3D printing are submitted to be printed. For this iteration, students designed wheels and pulleys. For the next time this project is completed, students will also design a frame for their cars to increase the stability. Construction of an electric car is an engineering/ technology project. When you try your car in a race, the one that is built with more precision and more considerations, will be the fastest. To build and use this car as a science project, you may find a research subject that is closely related to that. For example you may try to find out: Which battery brand provides the most power to your car? What effect does wheel size have on the car's performance? What size combination for pulleys gives the best performance? (small to large?, Large to small? or same size?) What works better - the pulley system or gear system? Materials Needed Cars are to be made out found materials: cardboard, straws, wooden dowels (skewers), glue guns, 3D printed parts (Wheels, pulleys, frames?) Standards ‹National Science Education Standards Grades 5-8 (ages 10 - 14) CONTENT STANDARD B: Physical Science As a result of their activities, all students should develop an understanding of  Motions and forces  Transfer of energy CONTENT STANDARD F: Science in Personal and Social Perspectives As a result of activities, all students should develop understanding of  Risks and benefits  Science and technology in society CONTENT STANDARD G: History and Nature of Science As a result of activities, all students should develop understanding of  History of science ‹National Science Education Standards Grades 9-12 (ages 14 - 18) CONTENT STANDARD B: Physical Science As a result of their activities, all students should develop understanding of  Motions and forces  Interactions of energy and matter CONTENT STANDARD E: Science and Technology As a result of activities, all students should develop  Abilities of technological design  Understandings about science and technology CONTENT STANDARD G: History and Nature of Science As a result of activities, all students should develop understanding of  Historical perspectives ‹Standards for Technological Literacy - All Ages Technology and Society  Standard 7: Students will develop an understanding of the influence of technology on history. Design  Standard 10: Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation, and experimentation in problem solving. The Designed World  Standard 16: Students will develop an understanding of and be able to select and use energy and power technologies. Skills Learned motor electric car engineering 3D design Duration of Lesson Depending on what parts are available to students, and how many iterations of designs are allowed, can take up to two weeks of class Preparation Teachers could have all the supplies laid out for students, or the students can be made responsible for their own supplies. Teachers will introduce the electric motor lesson and have students explore how electric motors work. Students will learn how to design a scale model for their car. Rubric and Assessment Students will be graded on their designs and their cars ability to drive the required distance. Students will present their data and conclusions about their designs and performance as a final assessment by creating a PowerPoint describing their design process. References https://www.ieee.org/contrib/groups/public/@ieee/@web/@org/@educ/documents/file/20041417.pdfhttp://www.miniscience.com/kits/CAR_ELEC/