What we’ve done

While we have used this activity in school settings, we’ve more commonly used it for big drop-in events, like careers fairs and open days.

We’ve typically set up a glue-gun station which we can keep a close eye on, and several working tables with stocks of cardboard, scissors and masking tape. It’s good to have groups of people working alongside each other – often, they’ll iterate on each others’ designs collaboratively.

Separate from the work tables we’ve then had a long set of trestle tables as a ‘firing range’, with a tape measure stretched out, marks at 1m intervals, and a very clear start point. If your room has a high ceiling you’ll need 8 or so metres of tables (!).

We’ll only count balls which land on the firing range, and it’s really important that whoever’s staffing it shouts the distance clearly before anyone else can exaggerate it. We’ve sometimes had a leaderboard (cardboard strips, a sharpy, map pins, and a poster board).

What’s worked for us

At drop-in events like open days, we’ve set up working areas for about 30 participants at once (coming and going constantly), and three staff have been able to manage that reasonably well. A fourth is helpful. People might spend just a few minutes making the basic catapult, or they might dwell for several hours (!) honing their design, trying something different, experimenting, and determined to improve.

What’s worked less well for us

School classrooms can work, but you often have to launch on the floor to eek out that extra bit of ceiling height. If you’re like us, this is problematic for knees. Chasing ping-pong balls is particularly awkward.

The biggest challenge we’ve had has been some facilitators thinking of the activity as a ‘make and take’, and literally packing children off as soon as they’ve made a working catapult. Sometimes this is about capacity – if there are thousands of people at an event, you can argue it’s better to spread the activity thinly across more of them. But at other times it’s been a missed opportunity. In many ways this is a training issue, but we’ve found that ‘the tinkering mindset’ is sometimes hard to convey. More experienced facilitators and teachers are sometimes so well-versed in coaxing ‘success’ out of their students that they struggle instead to prompt for observation, ‘what if’ conceptualisation, and experimentation.

In Schools…

The biggest challenges in a school setting would be about the physical space: you really want a high ceiling, a long firing range, and plenty of standing-height table working areas. We’ve run it in a standard classroom with parent/child groups and it’s worked well enough, but a hall would be better.

Stating the obvious

Do make sure you’ve made a working catapult yourself. It helps to have a few working examples to show around, so participants can compare theirs with a functional example. But mostly, you need to check you have a combination of components that works. Problems can include:

• Particularly floppy paper cups. Don’t try with plastic cups, they’re too flimsy (not to mention the resource use issue).
• Rubbish spoons. Some cheap plastic spoons are just terrible. We’ve moved to wooden spoons from a catering supplier.
• Elastic bands either too long (not enough stretch to work at all), or too short/thick (immediately launch the ball into the next room).
• Hopeless sticky tape from the business-mandated office supplies company. Masking tape works, is easy to cut or tear, and is much more pleasant to work with than nasty sticky tape.