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!


• 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. $45 per week and/or
4:00 – 6:00 p.m. $90 per week

• Lunch: $65 per week, mandatory at Endicott

• Inquire about our Counselor in Training (CIT) program:
for students in high school

• Limited to 14 children, rising 5th to 9th grade

• $25 sibling or multi-session discount applies

• Call for your personal referral coupon code and save!

• Child to instructor & assistant ratio is 7:1 or less

• Your instructor: engineer, John Aviste at Regis College and TBA at other locations

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.

YOUR INSTRUCTOR …at Regis College, Weston MA
John Aviste, P.Eng.

John Aviste, P.Eng.

Engineering degree from the University of Toronto

One day John was visiting with his son Andrew and nephew Christopher, and asked if they had any ideas for a new summer STEM experience. Their answer? Catapults! Easier said than flung. And so the challenge was on. A trebuchet would be designed and built, combining a bit of structural and mechanical engineering. The best part is that now, students get to pore over the drawings and come up with their own design enhancements.

This summer Catapult Engineering is being offered at Lasell University, Endicott College and Southern New Hampshire University, in addition to Regis College. The Lead Instructor for these other locations will be announced soon and will be assisted by engineering student, Brett Zaorski.


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.

Catapult Engineering dates and locations