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Electric Vehicles

Building & Racing Your Own EV

2026-05-03

Today’s ET Lab is going to introduce you to Electric Vehicles. Does anyone’s family own an electric vehicle?

What are the advantages of an electric vehicle? How about disadvantages?

There is a lot of talk today about moving away from gas powered cars because burning gasoline or diesel fuel produces emissions that are harmful to our environment and contribute to global warming. The most popular alternative is the electric vehicle. In fact, General Motors and many of the other major car companies are committed to moving away from gas powered vehicles and eventually only offering electric vehicles. As you can imagine this effort will require the work of many engineers. There is an awful lot of engineering that goes into making any type of car and working to replace the traditional internal combustion engine with battery power presents many engineering challenges.

(If the students started the workbook before the Intro Presentation, the engineer might discuss the answers to the workbook questions.)

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Trolleys
Electric city transit buses
Drones
Electric-powered boats
Electric trains and monorails

What is an Electric Vehicle?

Some less-often thought of EVs include:

When we think of electric vehicles, we tend to think of passenger cars (sedans, SUVs, etc.). �But, an electric vehicle is any vehicle that uses electric propulsion to move!

So let’s think about what an electric vehicle (or EV) is. Because Tesla is so often in news these days, we generally think of a passenger car when we hear “electric vehicle” and consider it to be a relatively recent invention. It turns out that electric vehicles have been around for quite some time. An electric vehicle is any vehicle that is powered by electricity, or uses an electric propulsion system. Here, we have listed some less-often thought of EVs:

Trolleys (like the Streetcars in New Orleans) connect to electric power lines that run above the trolley car.

There are also electric city transit buses (like those that operate in Boston) that offer a much more sustainable option than traditional busses that run on diesel fuel.

Drones are battery powered, too. Currently, there aren’t many other aircraft that are electric and this is because the batteries required to power such a heavy vehicle would be very large. One of the advantages of the internal combustion engine is that it can generate a lot of power.

Electric-powered boats represent a very small percentage of the boat market today but are expected to grow as the technology improves.

Electric trains and monorails common at airports and theme parks - including Disney World - are another type of EV.

Can anyone else think of another type of vehicle not listed here that could use electric power? (electric bikes or scooters)

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GASOLINE

Gas Tank

Carb

Smog Controls

Water Pump

Gas Pump

Oil Pump

Generator

Exhaust System

Engine

Starter

ELECTRIC

Charger

Battery

Controller

Motor

What are some of the benefits of an electric vehicle’s simpler design?

Electric Vehicles vs. “Traditional” Vehicles

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EV Efficiency �(miles/kWh)	Cost of Electricity (per kWh)	Fuel Economy of Gas-Powered ICE Vehicle (mpg)	Cost of Gas (per gallon)
3.5	$0.17	27	$3.12

ICE = Internal Combustion Engine

Cost to “Fuel” EVs vs ICE Vehicles

In order to compare the cost of travel for an electric vehicle versus a vehicle with an Internal Combustion Engine, we need to look at how far you can travel for a $1. We can’t use the traditional miles per gallon metric because electric vehicles don’t use gallons of gasoline. Based on an electric vehicle efficiency of 3.5 miles/kWh and the cost of electricity at [about 17] cents per kWh, an electric vehicle will travel about 20.6 miles for $1.00. Based on an average of 27 mpg for gasoline vehicles and a gasoline cost of [$3.12]/gal, the gasoline-powered vehicle will go about 8.6 miles. So, the distance that can be traveled for a fuel cost of $1.00 is more than three times as far with an electric vehicle.

But, as we know, gas prices can be more expensive, and are currently at least $3.12 per gallon. The average price of gasoline in NYC is just under $4. This means that in terms of cost, it is even cheaper to drive an electric vehicle compared to combustion engine vehicles. An EV can travel much further than an ICE vehicle per dollar spent “fueling” the car (where fuel is either electricity or gas/diesel).

It should also be noted that electricity prices vary by what part of the country you’re in, but are less than 20 cents per kWh on average.

It looks like EV would be the best choice but other factors such as ease of access (gas station vs charging station) and range (200 miles vs 600 miles depending on tank

https://avt.inl.gov/sites/default/files/pdf/fsev/compare.pdf

https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_a

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ELECTRIC VEHICLES STUDENT KIT
1 kit for every 4 students
Item	Quantity	Photo	Item	Quantity	Photo
Gear Kit Axles (2) Belt (2) Pulley (2) Gear (3) Wheels (4) DC Motor (1) Motor Mount(1)	1		Paper Roll	1
			Coffee Straws	2
			Regular Straw	1
			Propeller	1
			AA Batteries	2
Popsicle Sticks	25		Jumper Wires (7 inch)	2
Double Battery Holders	1

EV TEACHER KIT
Materials will be distributed throughout the class.
Item/Link	Quantity	Photo
Masking Tape	1
Double Battery Holders	3
Jumper Wires (7 inch)	6
Motors	3

ELECTRIC VEHICLES

CLASSROOM EXTRAS
Item/Link	Field Formula	Photo
Glue Guns	1 for Every Other Lab Group (Max of 8)
Extra Glue Sticks (20 long or 40 short)	Sticks for Every 30 Students (~2 sticks per lab group)

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SPEED CHALLENGE

Which EV can travel the fastest across a flat race track or a complex obstacle course?

SAFETY AND DURABILITY

This vehicle functions after �a crash and/or �drop test

AESTHETIC APPEAL

This vehicle body looks like a real EV in terms of color, artistry, detail, and aesthetics

MASS AND MATERIALS

This vehicle minimizes mass and uses recyclable materials

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Design Steps

Choose the Driving Force

(propellers, gears, or pulleys)

PROPELLER

GEARS

PULLEYS

Connect the propeller, gears, or pulleys that you chose in Step 1.

Place the axles through the straw and attach the wheels.

Circuit & Motor

Axles & Wheels

Create a car base

(using cardboard, popsicle sticks, bottles, etc…)

Battery Note: If you have 2 different kinds of batteries, make sure to only use 1 type together (either both rechargeable or both non-rechargeable batteries)

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GEAR RATIO =

# Driven Gear Teeth (Output)

# Teeth on Driving Gear (Input)

PULLEY RATIO =

Diameter of Driven Pulley

Diameter of Driver Pulley

Gears

Propeller

Pulley

How will you make it move?

Choosing a Driving Force

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https://www.makerspaces.com/propeller-car/

Propulsion Option 1: Propeller

Some ideas to spark your imagination:

Check out this Propeller Boat!

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Propulsion Option 2: Gears

EV with Gears

NOTE Teams will have to optimize the system for speed and torque. One challenge will be a race. Another challenge may involve rolling over a few bumps (flat rulers) in the race

GEAR RATIO =

# of Driven Gear Teeth (Output)

# of Teeth on Driving Gear (Input)

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Propulsion Option 3: Pulley

EV with Pulley and EV with Gears

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Divide the meters traveled by the time at each interval to see how the average velocity changes during your race

Trial #	Time at 1 m (s)	Avg Velocity over first 1 m (m/s)	Time at 3 m (s)	Average Velocity between �1 and 3 m (m/s)	Time at 5 m (s)	Average Velocity between �3 and 5 m (m/s)
EX:	2.3 s	(1-0)/(2.3-0)= 0.43m/s	5.5 s	(3-1)/(5.5-2.3)=0.63m/s	7 s	(5-3)/(7-5.5)= 1.33m/s
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2

DEFINITION

Average Velocity = change of distance / change of time

Insert Here

Testing - Velocity

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Divide the velocity you just calculated by the time at each interval to find your accelerations