Launchers are perfect first engineering projects: cheap materials, a dramatic result, and a clean measurement (distance or height) you can repeat dozens of times. These projects cover catapults, elastic launchers and rockets, each with the variables to test already laid out.
6 published projects in this collection
Pick one thing to vary — arm length, band tension, water volume, nozzle size — and hold everything else constant, including the projectile and the launch angle. Mark a consistent release point and measure from it every time; small setup differences easily swamp the effect you're testing.
Ten launches per setting is a good target: launch distances vary, so a single 'best shot' proves nothing. Average your trials and show the spread — that honesty is what turns a fun demo into an experiment.
A materials list with costs, numbered steps, safety guidance, the variables to change and control, and a data table you can fill in — plus community results from other builders once people start sharing theirs.
By subject
By school level
By difficulty
Preparing for a fair? Read the science fair guide or record your data in the lab.
They are drawn from the whole library by topic, across every subject and school level, so the collection mixes quick afternoon tests with full science fair entries. Each project page states its subject, level and difficulty.
A research question and hypothesis, the independent and dependent variables, the variables to hold constant, a full materials list with costs, numbered steps, safety guidance and a data table you can fill in as you test.
It varies, so every project page states a cost estimate and a realistic time estimate up front. You can rule a project in or out before buying anything.
Some do. Every project lists its hazards and whether adult supervision is required in an at-a-glance panel on its page, so you can check suitability before you start.