Trajectory

Participants: 2

Materials:

• Build

• Design log

• Calculator of any type (although I don't find it particularly helpful).

• Also bring data for yourself in addition to the design log so you know what to do

Your device sits in an area on the ground and you stand a meter or so away, pulling a string (or something else) to fire your device. You'll shoot at 2 targets which are on the ground and the goal is to be as close to them as possible. You get 2 shots at each target and can readjust your device in between. Only the best shot at each target matters.

As I said, there's a lot of freedom in designing this. The important thing is to have it be able to shoot fairly consistently, and be able to make 8 meters. Try not to overcomplicate it, there are a lot of simple solutions which work well. After you have made it really comes the important part where you test your device. You should test it hundreds of times so you know what happened when things go wrong.

See here for my example design log (with photos): 2021-22

Some basic materials you'll need are:

• Wood and wood glue

• Screws

• Something elastic (thin rope, or rubber)

• String for release mechanism

• A few balls (ping pong, foam golf, or tennis)

I would read about elasticity, tension and torsion, to come up with a good design. I chose rope but I'm not sure it's the best idea since rope's properties change a lot with temperature, humidity.

Here's someone else's design that worked quite well so I would consider what they did (if I make a new device, I would probably replicate it): https://docs.google.com/document/d/13UVXn2FROoMxiVfHPq6j-aabOvx5P9anEnVXCndMLw8/edit

Since timing can sometimes be hard, try to minimize what you have to change between shots.

Try to set as much up as possible before you give your device away at the beginning of competition day. Don't put your rope/rubber under tension though.

Work efficiently. This is where a lot of testing is necessary. You only have 8 minutes and that might sound like a lot, but setting up the device will take 2-4 minutes often so you need to be quick when transitioning between shots.