Catapult and Trebuchet Entries at the Last Fling Pumpkin Sling

All machines – catapults or trebechets – will need to be strictly mechanical – no engines, hydrolics, compressed air etc. Click here to download the rules. Click here to download the waivers for participation.

Also, for teachers, check out this sample curriculum from Sean Mc Geough Engineering Academy Instructor, SkillsUSA Advisor, Warren County Technical High School. His class build a small one last year, and are in the process of building a much larger one currently.

 

Categories

Prizes will be awarded in each class for each category – except Demo machines, where fees are also waived. All entry fees go back out as prize money. Categories will be as follows:

Trebuchet - Long Arm (6 foot or more total arm)
The basic idea of a trebuchet is to transform the potential energy stored in the lifted heavy mass into the kinetic energy that is the motion of the smaller mass (the pumpkin). It uses a short arm, which is weighted down with a heavy object to counterbalance against the long arm, where the projectile (the pumpkin) is placed. When the heavy mass of the short arm falls down, it provides energy to fling the long arm.

Trebuchet - Short Arm (Less than 6 foot total arm length - from sling mount to fulcrum)
The basic idea of a trebuchet is to transform the potential energy stored in the lifted heavy mass into the kinetic energy that is the motion of the smaller mass (the pumpkin). It uses a short arm, which is weighted down with a heavy object to counterbalance against the long arm, where the projectile (the pumpkin) is placed. When the heavy mass of the short arm falls down, it provides energy to fling the long arm.

Catapult/Balista – with power adder (Ex. Winch, gears)
A machine using stretched springs or rubber bands, which store energy. When the springs or bands are pulled and then released, the stored up energy is transferred to the arm of the device, which hurls the pumpkin.

Catapult/Balista – without power adder (Ex. Pull arm back with your hands)
A machine using stretched springs or rubber bands, which store energy. When the springs or bands are pulled and then released, the stored up energy is transferred to the arm of the device, which hurls the pumpkin.

Torsion Catapult
The basis of a torsion powered catapult is using rope strung into tight coils as a power source. One benefit of the torsion bundle was the spring can be made very large and powerful allowing the catapult to hurl relatively heavy objects a considerable distance.

Above and Beyond
Any catapult shooting more than 30-50% farther (to be decided when tallying results and announced with results) may be moved to this group to even out the playing field for other teams.

World Competetive - (Delaware Competitors)
Any category but air cannon. These machines will not be in competition with the other groups. They are welcomed for practice throws, measured distance, and demonstration. Most importantly FUN. Space limited. Please consult organizers on field of play and your throwing distances and pumpkin requirements.

 

If you are looking for some plans, here are a few links

www.realtrebuchetplans.com

www.learntobuildcatapults.com

http://www.shoshone.k12.id.us/medieval/blueprin.htm

diycatapults.com/catapult-plans-menu?page=shop.product_details&flypage=flypage.tpl&product_id=1&category_id=1

 

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