What do we do at Catapult Engineering? Why, we siege the day, of course! Teams build large outdoor trebuchets—catapult-like siege engines—for medieval challenges, like knocking down a mock castle wall. Hands-on engineering at its best: you get to break things!


Any 2nd week $50 off • 3rd week $75 off • 4th+ week $100 off

• Five-day, Monday to Friday program:
9:00 a.m. to 4:00 p.m. each day

• Optional extended care:
8:00 – 9:00 a.m. $55 per week and/or
4:00 – 6:00 p.m. $110 per week

• Bring your own lunch at Lasell University

• Apply for our Counselor in Training (CIT) program:
Rising 10th-12th grade students call (315) 773-5673

• Limited to 12 children, rising 5th – 9th grade
Grouped according to age!

• Save with two or more weeks

• Scholarships available, call (315) 773-5673

• Earn money by Referring a Family

• Child to instructor & assistant ratio is 6:1 or less

• Your instructor: an engineer, scientist and/or scholar


John Aviste

Engineering – University of Toronto

One day, John asked his son Andrew and nephew Christopher if they had any ideas for a new STEM camp and in a flash they replied, “Catapults!” And so it began. The first trebuchet was completed in the dead of night. It was ready to fire and aimed directly at the windows of John’s home. His dog Atticus was watching from the inside. The trebuchet was much too heavy to turn around, so he loosed it anyway, using a small sack for a projectile. Luckily, the trebuchet did not work and the sack went about 3 m. Now the range of this trebuchet is in the order of 40 m and each year our catapult engineers manage to improve its performance. Some things are just easier said then flung!

Program Curriculum

Children will learn to read and follow engineering plans to build an outdoor trebuchet within a team. They’ll learn engineering and construction principles and work with a variety of hand tools. Each child also assembles a take-home tabletop hurling machine, which is used in indoor play. Indoor medieval art projects and outdoor games keep everybody energized!

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The culmination of the week is a demonstration of the trebuchets for friends and family. The teams do all the figuring, aiming, positioning, and loading. We emphasize safety and adult supervision, so it is the lead instructor who inspects and sets the trebuchet before allowing it to be released.

This fun medieval week allows your child to explore structures, physics, statics, mechanics, joinery, simple machines, construction and more, working with tools like tape measures, protractors, squares, levels, wrenches, levers and fulcrums, wedges, pulley blocks, and mallets.
In the process of building their own trebuchets, they’ll develop team building and leadership skills as they solve engineering problems, and enjoy the fun and satisfaction of building a machine that works with spectacular results!

Why choose EOS Catapult Engineering?

Really? Knocking down a castle wall from 40 meters away with a trebuchet that you have built, set up, and tested with fellow medieval engineers? Even adults want to register for this week!

Working in collaboration with fellow team members, your child will soon experience the satisfaction of performing a job, and doing it well, to advance a team goal. Children revel in the workshop atmosphere. Real engineering drawings and hand tools, fun physics, estimating, testing, strategizing, and action all combine to advance skill sets and build confidence.

Siege the day and register!