Nothing really went well for us. The trebuchet should have worked, but I honestly don't know why it did not. The only good thing that came from this was the experience of making something from scratch. Some recommendations for future trebuchet makers is to make sure your pouch works. This is one of the most important parts of the trebuchet. Everything else worked perfectly in my eyes. This was a fun and challenging project. Took a lot of time and work to put this together so make sure you don't leave this to the last day or two.

Overall our trebuchet didn't do very well. Our average distance over 5 attempts was only .44 m.
Attempt 1- 0m
Attempt 2- 0m
Attempt 3 - 1.0 m
Attempt 4- 1.2 m
Attempt 5 - 0m

For the accuracy part of the competition, ours was 13.5 m away from the target.

If I had the chance to modify our trebuchet I would change the pouch to something that would release the ball better when it needs too. I think if it was made of different material then what we used it would have been better.
The overall design of the trebuchet was pretty good. The only thing that didn't really work was the pouch and releasing of the ball. I wouldn't change anything but the pouch.

Our trebuchet ready to go.

The tennis ball awaiting to be flung across the gym.

Cardboard Trebuchet Post

A big physics concept that makes the trebuchet work is gravity. Gravity pulling down on the counterweight has the biggest effect of the distance travel by the ball. Gravity itself is a environment factor so it cannot be change. The counterweight however can be changed so its a performance factor. Another factor that effects the performance is the angle of release.  This can also be changed. A 45' angle would be the best for a good release. Our cardboard trebuchet went just over 6 meters. and we got it to hit inside the circle.

Test Day Post

A major change we did to our actual trebuchet was we decreased the arm length. Before it was too long so it wouldn't be able top work right. Now the arm will be able to spin without catching on the bottom of trebuchet. Another thing we had to change is that our weight bucket broke. We still haven't yet come up with a solution for that but I think if we find a stronger buckets that can hold more weight it should work out better. The last thing that needed to be changed was the yarn attached to the pouch. It was a little think so it wouldn't come off and let the ball go. A thinner piece of string will be more effective so it will release the ball better.

The farthest our ball went was only a meter and that was wit my pushing the arm down. As soon as a effective way to have weights attached to the end of the arm is found, I think our trebechet will do a lot better.

The most interesting thing about the field trip i found was the trip to pizza hut.... just kidding. I actually found the power plant to be really education and our tour guide seem to know his stuff. It was really cool to see where our power comes from. Something we take advantage of every day but most don't really know the way it was made. The trips to ACC weren't that meaningful to me because i don't plan doing any of the fields we saw there.

The most limited restriction was the "no parachute" restriction. The container would drop faster and harder then it would with a parachute, so we had to worry more about padding and the impact of the container. Also the size restriction was a bit tough but it was pretty easy to follow once we had a design plan to follow.

The most effective part of our containers design was the tissue we had to protect our egg for hitting the inside of the container. It also stopped the egg of moving around inside the container. The only downside was we had no tissue on the top of the container so if it landed on the top, the egg would break. The least effective part of our design was tying the egg to the top of the container. It really didn't do much because the tissue made limited moving space anyways.

If  I was to do this again but with 2 eggs, i would do the same thing but i would need to put a soft barrier between the eggs  because the biggest danger to the egg is the other egg. I would probably put a piece of cardboard wrapped in bubble wrap in between the eggs still with the tissues around it. I would also probably need a slightly bigger container to hold both eggs and have enough room for tissues.
 

Egg drop Success? YES!
Mass of container- 76.1g
Mass of egg- 57.2g
Mass of bag- 2.7
Score- 147.05
Drop time- 1.29s

Our container falling!!!!!! 

Completion day Preparations

Test Day Post

 Our container did great! It did 1 meter, 2 meters and 3 meters with no problem. It did break at 5 meters but i think that might be because our container rolled down stairs after surviving the 5 meter drop. We moved to a different staircase and tried 5 meters again (with no chance of rolling down stairs.) The egg was fine after the fall. The only change i would make to our container is add more of  the padding on the inside if possible. I think the egg shouldn't crack if the padding prevents it from moving.

This is the inside of our container. 

 

This is the first egg drop test, when the container rolled downstairs.

This is the second drop. with no roll down stairs.

Our spaghetti bridge. Pic by Mr. Bertram. 

Me and my group with our bridge.  Pic by Mr. Bertram.

1. The part of the project I found most rewarding is the destruction part. We got to see our hard work pay off and see how long our bridge could hold out. The most rewarding feeling was the one I got when our bridge held over the minimum.

2. The strength of our bridge came from the triangle supports under the spaghetti block on top.

3. I would change the flat part of top. I would make it more reinforced in the middle. This would maker it stronger in the middle. I would also reinforce it more on the sides. Our spaghetti  bridge was only 237 grams. So we had about 115 more grams we could have added to make it more reinforced.

4. A tip to future spaghetti bridge designers is not to let a cat jump on you bridge. It will break!!!! Cats are not to be trusted.