The Pitch

Materials List:

Chassis: 3D printed plastic

Wheels: Four rubber wheels, each 5 cm in diameter

Axles: Two metal axles, each 10 cm in length

Motor: One DC electric motor

Battery Pack: Holder for 4 AA batteries (6V total)

Switch: On/off switch

Wires: Various lengths for connections

Soldering Iron and Solder: For secure electrical connections

Plastic Gears: To transfer power from the motor to the wheels

3D Print Design: The 3D print design for the car chassis includes slots and mounts for all the components: motor, battery pack, axles, and wheels. The design ensures that everything fits securely, and that the car is balanced for optimal performance.

Circuit- The motor is powered by the battery pack and controlled by a switch. We will:

Connect the positive terminal of the battery pack to one terminal of the switch.

Connect the other terminal of the switch to the positive terminal of the motor.

Connect the negative terminal of the motor back to the negative terminal of the battery pack.

Justification of Design:

Applying Course Concepts:

Electric Circuits: The motor of the car is powered by a straightforward series circuit. By flipping the switch, we can regulate the power flow and turn the motor on and off. This configuration is simple and effective, which makes it perfect for our little electric vehicle.

Force and Motion: The foundation of our design is Newton’s second law of motion, which states that F = ma. Greater acceleration can be produced by the force created by the motor when a compact, light chassis is used. The car’s dimensions and weight were selected to maximize this force-mass balance.

Energy Conversion: To drive the car, chemical energy is converted by the battery pack into electrical energy, which is subsequently used by the motor to produce mechanical energy. Designing a workable electric car requires an understanding of these energy transformations.

Friction and Traction: The car won’t slip since the rubber wheels are designed to have strong traction on the surface. Effective conversion of the wheels’ rotational motion into forward motion depends on this friction.

Additional Research

I performed a ton of extra research to maximize the performance of the electric car and to further support the design decisions I made in order to go above and beyond in this pitch. The following are the main fields of study:

DC Motor Selection

Research Insights:

Motor Efficiency: An electric car’s total performance is greatly dependent on the efficiency of its DC motor. A DC motor’s efficiency is contingent upon both its load and operating conditions, as stated by All About Circuits. A engine that is very efficient at modest loads is perfect for our automobile.

Torque and Speed Balance: According to the Pololu Motor Selection Guide, choosing a motor requires striking a balance between torque and speed. greater acceleration will come from a motor with more torque, and greater top speed will come from a motor with more speed.

Gear ratios: Gear Ratio Optimization: By changing the torque and speed connection, gears can have a big effect on how well an automobile performs. Higher gear ratios increase torque but decrease speed, and vice versa, according to How Stuff Works. An ideal gear ratio will allow our car to accelerate with enough torque while still having a high top speed.

Useful Example: In the example from the YouTube video we are watching, the gear ratio is 1:3, which means that for every wheel gear revolution, the motor gear turns three times. This offers a little electric car an excellent balance.

Wheel Size: Effect on Torque and Speed: The Exploratorium states that the wheels’ size has an impact on torque and speed. Smaller wheels turn with less torque but cover less ground each rotation than larger wheels, which require greater torque to turn.

Wheel Diameter: 5 cm is the ideal wheel diameter for our car since it strikes a compromise between delivering sufficient torque for acceleration and reaching a respectable peak speed. Science Buddies supports this decision.

Battery Life and Power Output: Battery Efficiency According to The Battery University, battery capacity and discharge rate have a big influence on how well battery-powered gadgets work. AA batteries offer an excellent combination between energy density and power output for our automobile.

Voltage considerations: To make sure the motor has adequate voltage to run well, use a 4 AA battery pack (6V). Engineering Toolbox supports this configuration by stating that stable voltage maintenance is essential for reliable motor performance.

FINAL POST:

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FINAL RESULT WE PLACED 3RD IN THE RACE THIS PROJECT WAS SO MUCH FUN REALLY ENJOYED THIS PROJECT!!!!

Research Citations

“How to Make an Electric Car” – Creative Channel on YouTube. Available at: https://www.youtube.com/watch?v=7Zl4fpM2S7g&t=215s

“Electric Circuits” – Physics Classroom. Available at: https://www.physicsclassroom.com/

“Newton’s Laws of Motion” – Khan Academy. Available at: https://www.khanacademy.org/science/physics/forces-newtons-laws“Where Does the Power Delivered to Car’s Wheels Go?” Physics Stack Exchange, physics.stackexchange.com/questions/518779/where-does-the-power-delivered-to-cars-wheels-go.

Byju’s. What Is a Streamlined Shape- How Is It Useful- – Physics Q-A. 4 July 2022, byjus.com/question-answer/what-is-a-streamlined-shape-how-is-it-useful.

“How Can I Give My Shoes Better Traction?” MetaFilter, ask.metafilter.com/77841/How-can-I-give-my-shoes-better-traction.

Primary Connections: Linking Science With Literacy. www.primaryconnections.org.au/themes/custom/connections/assets/SBR/data/Phy/sub/seriespara/seriespara.htm#:~:text=If%20two%201.5%20volt%20batteries,voltage%20of%20each%20individual%20battery.

Change of State – Help. www.physicsclassroom.com/Concept-Builders/Newtons-Laws/Change-of-State/conceptBuilderHelp/help5#:~:text=But%20the%20car%20inteacts%20with,applied%20force%20(Fapp).

Martin, Alexis. “Friction and Braking.” Online Learning College, 17 Aug. 2022, online-learning-college.com/knowledge-hub/gcses/gcse-physics-help/friction-braking/#:~:text=It%20is%20harder%20for%20a,vehicle%20such%20as%20a%20Mini.

“How Does Your Car’s Wheel Size Affect Its Performance? – RNR Tire Express.” RNR Tire Express, 2 May 2021, rnrtires.com/tips-guides/how-does-your-cars-wheel-size-affect-its-performance/#:~:text=Increasing%20the%20wheel%20diameter%20will,will%20have%20higher%20top%20speeds.

Brian Dengel. 15 June 2022, gearsolutions.com/departments/tooth-tips/load-speed-and-torque/#:~:text=Understanding%20these%20relationships%2C%20you%20can,gear%20teeth%20will%20also%20change.

Tallodi, John. “10 Of the Most Aerodynamic Cars Ever Made.” carwow.co.uk, 31 July 2023, www.carwow.co.uk/best/most-aerodynamic-cars#gref.

Car Aerodynamics: Combatting Air Resistance in Cars. www.oponeo.co.uk/blog/car-aerodynamics-and-air-resistance#:~:text=How%20your%20car%20handles%20air,impact%20on%20your%20fuel%20efficiency.

Learn About Children’s Riding Toy Batteries. www.batteriesplus.com/blog/power/riding-toy-batteries#:~:text=When%20selecting%20a%20riding%20toy,require%20a%2024%2Dvolt%20battery.

Primary Connections: Linking Science With Literacy. www.primaryconnections.org.au/themes/custom/connections/assets/SBR/data/Phy/sub/gears/gears.htm#:~:text=The%20simplest%20form%20is%20two,gear%20and%20a%20driven%20gear.

WestCoastSuperFastHPE. “A Breakdown of What a Spoiler Does for Your Vehicle.” Westech Performance Group, 14 Aug. 2022, westechperformance.com/2022/06/02/a-breakdown-of-what-a-spoiler-does-for-your-vehicle/#:~:text=To%20lower%20wind%20resistance%20(or,increases%20traction%20at%20high%20speeds.

Everything You Need to Know About Traction. www.taylorgm.com/everythingyouneedtoknowabouttraction.html#:~:text=By%20definition%2C%20traction%20is%20a,surfaces%20like%20gravel%20or%20mud.

Morris, Austin, and Austin Morris. “Traction Control System: How It Works and When to Use It.” Kelley Blue Book, 6 June 2023, www.kbb.com/car-advice/traction-control/#:~:text=It’s%20safer%20to%20keep%20your,you%20find%20yourself%20spinning%20wheels.