Creating an egg launcher as a physics class project that lets students reinforce their mechanical aptitude, ingenuity and understanding of concepts, such as torque and acceleration. Most egg launcher projects provide fairly detailed specifications about launcher size, distance to target and how much practice and adjustment students can carry out on the site of the final trial.
An egg launcher designed in the style of a catapult depends on a launching arm propelled by a spring or other source of tension that can be released suddenly. An advantage of catapult-style egg launchers is their potential for high accuracy and consistent range once properly calibrated. Build a frame, launching arm and either a spring that pushes the launching arm up or a crank that uses the arm's own tensile strength to build enough pressure for a launch. The frame should stop the arm at a certain angle after the trigger releases it.
A trebuchet is similar to a catapult, but instead of pressure on the launching arm, it is driven by a counterweight that drops suddenly and lifts the launching arm swiftly into the air. Usually a trebuchet has a flexible sling at the end of the launching arm that snaps up to add more leverage to the launch. Trebuchet-style egg launchers have a relatively long range but may be harder to launch with consistent accuracy.
An egg launcher in the style of a cannon or bazooka launches the egg through a tube by building up pressure behind the egg and releasing it suddenly. The pressure may come from a chemical reaction or an air compressor. Cannon-style egg launchers have the advantage of a very long range and the potential for great accuracy when they are designed and calibrated properly. Be careful, though, as the high-pressure launches or explosive reactions involved make this style more dangerous to construct and operate than other models.
Slingshot-style egg launchers use the tensile strength of a flexible band to launch the payload. The band may be elastic or just a slightly stretchy material under high tension. Slingshot launchers that aim for consistency should have a frame that holds the band at both ends and in the middle. The part that holds the middle should be a trigger that can pull the band back to a point that can be calibrated for range then released to launch the egg. Slingshot launchers are relatively simple to build but may have a lower range and accuracy than other styles.