OMG is holding a trebuchet contest!

This is your chance to build the best miniature siege engine in Omaha.  Work by yourself or in a small group to make the best golf-ball*-throwing device you can imagine.  We will then compete for range and accuracy to crown a champion. The contest will take place at the Makery on September 21st.

Although the competition is called “Trebuchet Contest,” your device does not need to look like something out of the middle ages.  You can use any design, any materials, any construction techniques, and in fact any launch techniques you’d like.  We want to keep things interesting, so the rules for this contest are very lenient:

1. The energy used to launch the projectile may come only from the gravitational potential energy of a mass falling no greater than 16 vertical inches.  No explosives, precompressed springs, compressed gasses, batteries, or any other sources of energy.  Gravity only.  However, you can use all those things as intermediate steps if you’d like – if you use gravity to compress a spring, or use electronic timing to coordinate the firing, that’s just good Maker spirit.  Just be prepared to prove that you’re not contributing any extra energy to the projectile.

2. Your siege engine requires a remote triggering mechanism.  Mechanical, electronic, whatever.  You need to be ten feet from the firing position during your shots, and away from the most likely misfire direction (for example, on a standard trebuchet you need to be off to the side, out of the plane of the arm).  We want to keep things safe.

3. You cannot aerodynamically assist the projectile in any way.  If you need wadding to seal the projectile in the barrel of your gravity-charged pneumatic cannon, that’s fine.  If you want to use a sling which stays attached to the projectile instead of the trebuchet, well, you’re the one who thinks it’ll be competitive to throw more weight than anyone else.  But whatever you do, the projectile has to take a ballistic trajectory once it leaves your machine.

We’re trying to keep things interesting and attract the widest range of designs by keeping the rules loose.  Please don’t abuse this privilege – nobody wants to read a ten-page rule book covering every possible situation.  Tech inspection is going to have a “spirit of the rules” philosophy, and you should keep that in mind while working on your design.  If you have a creative idea or think you’ve found a loophole in the rules, please bring it up with Ben as soon as possible.  Most likely it will be allowed, but if you show up on competition day with something ridiculous, having never discussed it with the organizers, you might find yourself disqualified.  We promise flexibility and absolute discretion – if we allow your cunning plan, its secret will be safe, and we promise not to steal it for our own designs.

*Golf balls make ideal trebuchet projectiles.  Unfortunately, they’re a bit dangerous and bouncy.  To dramatically increase the chances of scoring each shot by ensuring we can actually find each projectile, we won’t be using golf balls.  Competition projectiles will be approximately equal in size and exactly equal in mass to a golf ball.  Projectiles will be supplied for scored shots, although you may test with anything you like.

Competitions and Scoring:

The exact equations used for scoring will be revealed the day of competition, to prevent any rules-lawyering and to allow us more time to perfect them.

• Longest Range

  • You will be scored on your ability to efficiently throw the projectile as far as you can.  The mass of your power weight will be taken into account, so if you decide to increase performance with extra weight, make sure you’re getting a proportional gain in range.

• Best Accuracy

  • You will be scored on your ability to hit a predetermined target at a distance of your choosing.  The main goal is accuracy, but your chosen range will also affect your score – a 10-foot miss from 100 feet isn’t as impressive as a 10-foot miss at 200 feet.