February 21st: 

Original Plan: Figure out the scale of the trebuchet, make the frame, and the supporting structure, combine the trebuchet sides and attach bracings.

In reality: 

Considering the trebuchet size ratio, our team constructed a trebuchet prototype that was 50 centimeters long, 18 centimeters broad, and 60 centimeters high. Secondly, we completed the framing out of wood blocks and sticks, which we screwed together after drilling each piece.

 

We utilized wood glue to attach the supporting framework to the trebuchet because drilling it would be difficult due to its tilted design. Since the bracings are one of the most critical structures to keep the device from disintegrating while it is in use, adding them is another crucial consideration.

To link the two sides of the trebuchet together, we used three 15-centimeter-wide wooden blocks. Only one side of the trebuchet was drilled because the pivot arm at the top still needed to be added.

 

 

February 23rd:

Original Plan: Prepare the pivot arm, and drill the holes for the dowel that goes through the frames and the component of the trebuchet.

In reality:

After attaching the bracing that connects the two sides of the trebuchet, we drilled 3/16″ holes in the dowel on either side of the arm and slid one 3/16″ dowel piece into place. The wooden dowel keeps the arm of the trebuchet in place, and it’s the main feature that helps release the ping pong ball. Then we made the pivot arm. We glued two 50*8 wooden blocks together using wood glue to make them even more robust. We also drilled a 3/16″ hole on the 3/2 place of the pivot arm. And that wraps up the work that we did in this lesson.

 

February 27th: 

Original Plan: Mount the trebuchet track, attach the weight, and make the basket.

In reality:

Our group decided to make a track for the ping pong ball to let it launch smoothly and flawlessly. We used a 90-degree angled cardboard and cut it to 50 centimeters long; then, we drilled it on the bracings using screws. After doing some calculations, we added a 4 kg weight to the end of the arm, another vital aspect to remember. After considerable investigation, we discovered that we could utilize no extra metal weights. Our alternative will be two 2 kg wooden cylinders added on each side of the arm. (Seen in the picture)

Then it was time to make the basket; first, we used a small plastic round box as the basket and drilled holes on the side of it to attach the strings.

March 1st: 

Original Plan: Attach the sling to the trebuchet and finally test it.

In reality:

We drilled a closed iron hook on the other end of the trebuchet with a bending arc facing up. This will release the string earlier in the swing of the arm. We tied one end of the sling to the iron hook and one end to the bending arc. And finally, after 4 blocks of hard work, it was time to test it out.

 

 

The problems that we encountered during the trials:

• The ball was released too early.
• During the launch, safety cannot be guaranteed.
• The ball was launched backward.

We asked for feedback on how to solve our problem:

Mr. Diego:  You guys really need to modify your plastic basket since it launches backward because it isn’t deep enough. As fabric retains the ball more securely, you guys can utilize it.

Joseph Song: The ball should be heavier to launch further; the ping pong ball is too light.

Hugo Fong: I believe including a release mechanism is essential since there should be room between the launcher and the trebuchet, making it safer.

Our solution:

• Make a release mechanism using hooks and strings (As shown in the image below).

• Change the material of the basket into fabric.

• Increase the weight of the ball.
  • We used plasticine as the contour of the ball and a metal ball inside the plasticine to increase its weight

And that, ladies and gentlemen, wraps up the creation of our product. I hope you all appreciated the completed product, which is presented here.

• Enjoy😊