For the third and final mouse trap challenge we had to make a mouse trap powered vehicle that could travel 2 meters and stop in the red zone. It then had to shoot a pingpong ball three meters into a bucket. This was the hardest challenge that my group and I have faced, though we already had a vehicle and a catapult we had to somehow combine them, but it wasn't that simple. we started by cutting the base of the catapult that was constructed of a mouse trap with a spoon tuct taped to it. There was a piece of wood hot glued to the front of it to stop it from rotating 180 degrees. We attatched the catapult to the car using hot glue. The car's body was made of reinforced cardboard for the maximum ammount of strength. The axels were forged by only the finest of pencils. The wheels were constructed of cd's and for traction we wrapped the wheels in clay. The mouse trap sat on top, secured by hot glue. For the maximum ammount of distance we duct taped a pencil to the mouse trap.
First we had to come up with a way to get the mouse trap car to stop in the red zone. I let My brilliance take over and decided to use math as a way to make the car stop where I wanted it to. I figured that I only needed to find out how long the string had to be. I started by Measuring the circumferance of the wheels, 38 cm. I then measured the circumferance of the axels, 2.5 cm. The distance that it had to travel was 200 cm. I divided 200 by 38 (Because 38 cm is the distance the car travels with every revolution.) and got 5.26 cm. I then multiplied 5.26 by 2.5 (Because 2.5 cm is the length of string that unravels with every revolution) and I got 13.16 cm. I added 4.5 cm to 13.16 cm because 4.5 cm was the length of space between the axel and the end of the pencil. The length of the string had to be 17.66 cm in order for it to stop in the red zone. I cut the string and fastened it to both the axel and the pencil and tested it, and sure enough... It worked!
The next step was to figure out a trip mechanism so that after the car got into the red zone, the catapult would fire the ping pong ball into the bucket. We started by drilling a hole through the mouse trap and sticking a pencil through it. The pencil had a thin rod of metal hot glued to it that stuck out equally on both sides. It was made so that it could pivot. The metal rod would hold down the catapult and the pencil would rotate back as the car was moving. eventually the pencil would hit one side of the metal rod, making it pivot off of the spoon, thus releasing the catapult. At first this didn't work because the spoon had too much upward force and it pulled the pencil out of the hole. We then had to secure it at the bottom by hot glueing a "cardboard-like thing" to the bottom of it that would not allow the pencil to slip through. Then another problem we ran into was that the metal rod would fall off because it was only secured by hot glue. It was an easy fix because all we had to do is tape it a lot. After we put a slight bend in the rod, it worked perfectly.
We were ready for our first test and everything was going great until the car started bumping so much that the pingpong ball fell off before it could even launch. We tested it over and over again with the same result. We decided that it was the wheels that made it bump because the clay was uneven in some parts. We took some time to smoothen that out with our fingers and after testing it again our problem was fixed. Everytime we tested, our car would veer a little bit to the right so we fixed this by setting it up to the left more. Then after we thought everything was fixed, the catapult was shooting too far, Maison thought that maybe it didn't have enough arch. He hot glued small pieces of wood to the wooden "stopper" on the catapult so that it would stop earlier. This fixed our problem and we started on our trials. We were running out of time so we didn't test a lot inbetween trials. Our first one was a failure, as well as our second. We decided to do a test before our third one and we made it in. We did another test and missed. We had less than a minute left so we had to do our final trial. Everything was going perfectly, the car passed the first line of the red zone and the catapult was released. I saw the ball sail through the air, the entire room was silent. This was the moment of truth, life or death, no going back, all cards on the table. I saw it about to land before I heard the glorious sound *Thunk* we made it! All of our hard work had payed off, Ricky jumped in the air with his hands above his head, we even got a cheer from Mr. Schneider. It was a moment I will never forget, the best moment of my life. Afterwards I went to tell all of my friends. "You guy's wont believe it!" I said. *Friends ignore Bryce's existence* "I did it! I got it in the bucket!" I said. "cool" Ethan said. "I know right!!!" I said. I owe my success to my great, supportive friends!
First we had to come up with a way to get the mouse trap car to stop in the red zone. I let My brilliance take over and decided to use math as a way to make the car stop where I wanted it to. I figured that I only needed to find out how long the string had to be. I started by Measuring the circumferance of the wheels, 38 cm. I then measured the circumferance of the axels, 2.5 cm. The distance that it had to travel was 200 cm. I divided 200 by 38 (Because 38 cm is the distance the car travels with every revolution.) and got 5.26 cm. I then multiplied 5.26 by 2.5 (Because 2.5 cm is the length of string that unravels with every revolution) and I got 13.16 cm. I added 4.5 cm to 13.16 cm because 4.5 cm was the length of space between the axel and the end of the pencil. The length of the string had to be 17.66 cm in order for it to stop in the red zone. I cut the string and fastened it to both the axel and the pencil and tested it, and sure enough... It worked!
The next step was to figure out a trip mechanism so that after the car got into the red zone, the catapult would fire the ping pong ball into the bucket. We started by drilling a hole through the mouse trap and sticking a pencil through it. The pencil had a thin rod of metal hot glued to it that stuck out equally on both sides. It was made so that it could pivot. The metal rod would hold down the catapult and the pencil would rotate back as the car was moving. eventually the pencil would hit one side of the metal rod, making it pivot off of the spoon, thus releasing the catapult. At first this didn't work because the spoon had too much upward force and it pulled the pencil out of the hole. We then had to secure it at the bottom by hot glueing a "cardboard-like thing" to the bottom of it that would not allow the pencil to slip through. Then another problem we ran into was that the metal rod would fall off because it was only secured by hot glue. It was an easy fix because all we had to do is tape it a lot. After we put a slight bend in the rod, it worked perfectly.
We were ready for our first test and everything was going great until the car started bumping so much that the pingpong ball fell off before it could even launch. We tested it over and over again with the same result. We decided that it was the wheels that made it bump because the clay was uneven in some parts. We took some time to smoothen that out with our fingers and after testing it again our problem was fixed. Everytime we tested, our car would veer a little bit to the right so we fixed this by setting it up to the left more. Then after we thought everything was fixed, the catapult was shooting too far, Maison thought that maybe it didn't have enough arch. He hot glued small pieces of wood to the wooden "stopper" on the catapult so that it would stop earlier. This fixed our problem and we started on our trials. We were running out of time so we didn't test a lot inbetween trials. Our first one was a failure, as well as our second. We decided to do a test before our third one and we made it in. We did another test and missed. We had less than a minute left so we had to do our final trial. Everything was going perfectly, the car passed the first line of the red zone and the catapult was released. I saw the ball sail through the air, the entire room was silent. This was the moment of truth, life or death, no going back, all cards on the table. I saw it about to land before I heard the glorious sound *Thunk* we made it! All of our hard work had payed off, Ricky jumped in the air with his hands above his head, we even got a cheer from Mr. Schneider. It was a moment I will never forget, the best moment of my life. Afterwards I went to tell all of my friends. "You guy's wont believe it!" I said. *Friends ignore Bryce's existence* "I did it! I got it in the bucket!" I said. "cool" Ethan said. "I know right!!!" I said. I owe my success to my great, supportive friends!