Presentation on theme: "By Ricky Haitaian and Charlie Comer. How we built the crossbow. We started off by rolling up 4 half sheets of paper for the arms of the crossbow. Then."— Presentation transcript:
How we built the crossbow. We started off by rolling up 4 half sheets of paper for the arms of the crossbow. Then we rolled up 5 sheets of paper for the body of the crossbow. We put popsicle sticks in the rolled up arms and then we taped the arms to the body. We were going to use twine but we decided to use a rubber band so we didn’t have to buy anything, it also was less time consuming. We tied a bowline knot with the rubber band.
How we built the crossbow continued… We later added length to the crossbow so we could put the trigger back farther. We had made the trigger by placing a hole in the body of the crossbow with an exacto knife. We cut of a piece of a popsicle stick and put it in the hole. We did this so when we were ready to fire we pushed the popsicle stick down and the rubber band went loose and flung the arrow. We then decided to get the trigger mechanism out of the way and we just lined up the arrow with the rubber band and released the rubber band so it flung the arrow. We made the crossbow shorter because the rubber band was getting loose, we tightened it and it created more power. We used the end of the crossbow for a handle.
What did we expect to learn? We expected to learn how to make the basic structure of the paper crossbow. We also expected to learn how to make the crossbow flexible as possible so we could do this project correct.
What did we learn? We learned how to build a basic structure using tape and paper. We learned how to increase power with a crossbow and increase accuracy.
Challenges We had a really tough time trying to build the trigger mechanism because we could not find out how the guy in the video shot the crossbow. We later found a new way to shoot the crossbow which worked better than our previous attempt. We had a lot of trouble getting our supplies so we had to get them from Mr. P and Mr. McCloud.
Evaluation We think we did better than we expected to do on this project. We thought it would be a weak pencil shooter but then we modified it. We shot different objects instead of pencils and we strengthened the crossbow. Our arrows can shoot through cardboard and have a maximum length of about 70 feet.