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Engineering experiments and science fair projects

Hands-on engineering projects covering bridges, towers, catapults, boats and machines you build and test. Each one lists the exact materials, the time and cost involved, the variables to control and a data table you can fill in — so it works as a class activity or as a full science fair entry.

37 published projects in this collection

Choosing a engineering project

Engineering projects follow a design-build-test-improve loop instead of a single hypothesis. Record every version you build — the improvement story is the result.

What every project includes

A research question and hypothesis, an independent and dependent variable, the variables you hold constant, a materials list with costs, numbered steps, safety guidance and a reproducibility score based on how completely the method is documented.

Projects to try

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Which base shape makes a tower most resistant to shaking?

Build model towers with different base shapes from spaghetti and marshmallows or straws, then test their stability on a simple shake table.

Intermediate
Middle School +2
Several days
$15 materials

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Does the arm length of a catapult affect how far it launches a marshmallow?

Build a simple spoon or popsicle-stick catapult with adjustable arm length and measure launch distance.

Beginner
Elementary +3
Several days
$8 materials

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Does the number of gear teeth affect how many turns are needed to complete a rotation?

Use a simple gear or lever set to compare rotations needed between gears of different tooth counts.

Intermediate
Middle School +2
Several days
$20 materials

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Does truss shape affect how much weight a popsicle stick bridge can hold?

Construct small popsicle stick bridges with different truss patterns and load-test them until failure using stacked weights.

Challenging
Middle School +2
Several days
$15 materials

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Which insulated container keeps ice packs frozen the longest during transport?

Line small coolers with different insulating materials and time how long ice packs take to fully melt in each, simulating cold chain transport.

Intermediate
Elementary +3
1 day
$18 materials

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Which cushioning material best protects an egg from a drop?

Build egg protection cases using different cushioning materials and test survival rate after being dropped from a fixed height.

Intermediate
Elementary +3
Several days
$10 materials

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Does the amount of water in a bottle rocket affect how high it launches?

Launch a water bottle rocket using a low-pressure air pump launcher at different water fill levels and measure launch height.

Challenging
Middle School +2
Several days
$30 materials

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Which tower base shape supports the most weight before collapsing?

Build small paper towers with different base shapes and test how much weight each can hold before failing.

Intermediate
Elementary +3
Several days
$8 materials

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Which packaging design best protects an egg from a drop?

Design and test multiple egg-drop packaging solutions using different cushioning materials, dropping each from the same height and recording outcomes.

Beginner
Elementary +3
Several days
$10 materials

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Which gripper finger shape picks up the most objects successfully?

Build a simple lever-operated or string-operated gripper with interchangeable finger tips and test pickup success across various small objects.

Intermediate
Middle School +2
Several days
$20 materials

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Does roof angle affect how much rainwater a collection system captures?

Build model roofs at different slope angles connected to gutters and collection containers, then simulate rainfall to measure water capture efficiency.

Intermediate
Middle School +2
Several days
$20 materials

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Does a wider base make a tower more resistant to wind?

Build towers of equal height and different base widths and test them against a fan.

Beginner
Elementary +3
1–2 hours
$10 materials

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Does screen brightness affect battery drain?

Run a device at set brightness levels for fixed times and measure battery percentage loss.

Intermediate
Middle School +2
Several days
No-cost materials

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Does blade angle affect how much wind a model turbine can capture?

Build a simple model wind turbine with adjustable blade angles and measure rotation speed at a fixed fan setting.

Intermediate
Middle School +2
Several days
$18 materials

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How many filtration layers are needed to clear muddy water?

Build filters with different numbers of sand and gravel layers and measure the turbidity of the filtered water produced.

Beginner
Elementary +2
1 day
$12 materials

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How does blade number affect the power output of a model wind turbine?

Build model wind turbines with different blade counts and measure voltage output using a small DC motor generator and fan.

Intermediate
Middle School +2
Several days
$25 materials

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Does wheel size affect the speed of a battery-powered model car?

Build a simple battery-powered model car and test its speed over a fixed track using interchangeable wheel sizes.

Beginner
Elementary +3
Several days
$20 materials

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Does joint type change how strong a craft-stick frame is?

Build identical square frames with different joints and load them until they deform.

Intermediate
Elementary +3
Several days
$10 materials

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Which solar oven design reaches the highest internal temperature?

Build three solar oven designs using cardboard and foil and compare their heating performance under identical sunlight conditions.

Beginner
Elementary +3
Several days
$18 materials

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Does a wider wheelbase make a cardboard car corner better?

Build a model car with adjustable axle width and test cornering on a marked circular track.

Challenging
Middle School +2
Several days
$18 materials

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Does wheel size affect the speed of a model vehicle down a ramp?

Build or modify a simple model car with interchangeable wheel sizes and measure its speed down a ramp.

Intermediate
Middle School +2
Several days
$15 materials

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Does the type of growing medium affect plant growth in a hydroponic system?

Build simple wick-based hydroponic systems using different growing media and compare seedling growth in each.

Intermediate
Middle School +2
Longer
$30 materials

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Does wheel material change how well a robot climbs a slope?

Fit a robot with different wheel surfaces and find the steepest slope it can climb.

Challenging
Middle School +2
Several days
$30 materials

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Does blade angle change how much power a model wind turbine produces?

Build a cardboard-blade turbine and measure output voltage at several blade angles in a fan's airflow.

Challenging
Middle School +2
Several days
$25 materials

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Preparing for a fair? Read the science fair guide or record your data in the lab.