Catapult Build

Purpose

Catapult Build challenges teams to design and construct a working catapult from provided materials and then compete on accuracy and distance by launching a projectile at a target. It combines engineering thinking, creative problem-solving, iterative testing, and friendly competition. The tangible, dramatic result (launching!) creates high energy, memorable moments, and visible differences in team approaches to design and execution.

At a glance

• Group size: 8–40 participants (teams of 4–6)
• Duration: 45 minutes
• Difficulty: Intermediate
• Facilitation style: Timed challenge with testing
• Setting: Outdoors preferred; large indoor space possible

How to run

1. Brief (5 min): Your team must build a catapult that launches this ball as far as possible or as close to the target as possible. You have these materials and 25 minutes. Each team gets 3 launch attempts.
2. Build phase (25 min): Distribute identical kits. Teams design, build, and test. Encourage iterative testing.
3. Launch competition (10 min): Each team gets 3 attempts. Measure distance or proximity to target. Build drama with countdowns.
4. Debrief (5 min): What engineering principles made the best catapults? How did you iterate? Who took which roles?

Materials needed

• Building kits per team: wooden sticks or rulers, rubber bands, plastic spoons or cups, tape, string, cardboard
• Projectiles: marshmallows, ping-pong balls, or small soft balls
• Target (bucket, cone, or marked area)
• Measuring tape
• Safety glasses (recommended for launch zone)

Pitfalls & common mistakes

• Materials too flimsy: Rubber bands need to be strong enough to generate force. Test the kit beforehand.
• No testing during build: Teams that build for 25 minutes and test only at the end often fail. Encourage mid-build testing.
• Unsafe projectiles: Use only soft, lightweight projectiles. No stones, hard balls, or sharp objects.
• No clear launch zone: Designate a launch area with spectators behind the catapults, not in front.

Inclusion & accessibility

• The activity involves building and assembling — assign design, assembly, and testing roles to match abilities.
• Works at table height for seated participants.
• The visual spectacle of launches engages observers and builders equally.

Variations

• Accuracy Catapult: Target a bucket 5 metres away. Closest to centre wins.
• Distance Catapult: Longest launch wins. Open-field competition.
• Catapult War: Teams launch simultaneously at each other's castles (cardboard targets). Most hits wins.

When NOT to use this

• Without a safe, clear launch zone where spectators are protected.
• In confined indoor spaces where projectiles could cause damage.
• With materials that could create dangerous projectile force.

Source & further reading

• STEM education resources on physics and engineering.
• Various corporate team-building activity guides.