Engineering Project Outline: The goal of our project was to build a cannon launcher off of a given model (a model of a cannon that had already been created) and create a base for the launcher from our own ideas. (Each launcher for each group would be the exact same but the base and supports for the barrel of the cannons would be our own ideas and all different.) We were then tasked with shooting a tennis ball out of our cannons in a "game" of battleship.
Early on in our design process when we first printed out and cut our base supports we found that they didn't work. Alyssa was obviously sad. So was everyone else at the table. In our group we had somewhat of a strange dynamic where we could rarely ever decide on anything for sure so it was sad to see that a design we had finally agreed on didn't work. What we found out was we had forgotten to scale our supports up from our model to the actual size of the cannon and we forgot to measure certain parts of the cannon that we didn't realize would have any impact on the supports.
Next while we were building the actual main part of our launcher we had to use PBC pipe and the main part. The piping would be all connected together in the end to form our cannon. Each piece of pipe is connected by a special glue that is really strong. Before we put the glue on the actual pipe because of how strong it is we have to first prime the pipe with this purple primer.
When we first started making the launcher we were told that we needed to use two pieces of PBC pipe as the main base and structure for our launcher. We had to cut the pipe because we needed smaller pieces out of the overall large piece. We were given exact measurements that we needed from the pipe to build the launcher so we had to cut it down to make it fix the measurements
Next we put the wooden barrel support around our cannon and then secured and locked the pipe with a cap so the air could be locked in and stored. We had just printed out our successful barrel supports. We were so excited that our design had seemingly worked so we rushed into putting the cannon together and secured our barrel supports around our cannon barrels before we should have. We then quickly put a cap over the end of our pipe closing off the entire cannon to any changes so if we wanted to fix something we would have had to break our canon. Sadly the supports ended up breaking shortly after because we messed up and put on of our pipes in too far which made the cannon slanted a little. This didn't impact our shooting but next time we will remember not to rush and make sure everything is right and working.
Next we finished building our entire base part of the cannon which was the actual cannon that would launch a tennis ball. We built the cannon in the back of the engineering room, in the actual shop. Mr. Twilley as a bunch of tools and helpful machinery that we used to build our cannon. It took us about two class period to build the cannon and make sure everything was put in place.
While we were working on the base for our cannon and the actual supports that would hold the cannon up, we had to use the ShopBot. This machine is a large cutter type machine that can cut large and thick pieces of wood. First we created a drawing of what our base was going to look like on OnShape and the we sent that drawing to the printer in the shop that printed the drawing onto the piece of wood by cutting the shape out. The machine has a lot of power so Alyssa and I had to secure the wood to the actual machines with screws and nails first.
Next, when we were building the cannon we needed to put all of the pieces together and secure them to the base of our cannon so we spent a class period using glue to secure everything. This is a support that will be used to raise and lower the cannon so we can change the angle at which the cannon is shot. In this picture we were putting glue on the slots so we could put the piece together. When you're putting pieces of wood together we use a type of glue called wood glue that is a pale yellowish color.
When we were working on getting the finishing touches on our cannon and working on the pieces that would help us with angle elevation, we realized that we needed something really sturdy that would be able to hold up our entire cannon . Even though the pole is being used to change our shooting angle it still has to be able to hold up the entire cannon and move it up and down. It was a little too long when we first pulled it out of the back so we had to cut it down. We decided to use this piece because of how thick it was and how it was very sturdy when we pushed against it.
Next we had to cut out our washers. Our washers were going to be used for our lazy susan affect for our base. We wanted to be able to create a base that had full range of motion in a horizontal way so we could shoot at whatever angles we wanted to. The washer was going to sit in between the rectangular and circular parts of our base and help the wood move against each other easily and create less friction.
Next we had to build the main structural base for our cannon. Our cannon will sit on top of this and the large screws will secure into the ground so the cannon doesn't move. When we bring the canon outside we will push the entire mechanism into the ground and the screws will lock into the dirt making sure our cannon is very stable. The large circular part of the base is made to move analogously horizontally so we have maximum shooting range. There is a large piece of blue plastic that is sat under the circular part to make movement smoother.
Next, once our entire base was set up and put together we knew we wanted to know what angles we were shooting from so we decided to take a protractor and measure out the angles all around the entire base. We drew little ticks where the measurements landed and then we extended the lines so they were easier to see. This ended up helping us a lot because we knew exactly where we were shooting from each time which came in handy when recording our data.
At this point in time we had finished building the entire main cannon and we had finished putting the cannon on our base and putting the base together. We spent a few minutes looking at our cannon and walked around the cannon looking for anything we needed to add or clean up. We took towels and rags and we cleaned up anywhere there was excess glue or anything that wasn't pushed in all the way we made sure everything was together.
Finally we got to go outside and test our cannon. Once we were outside we set up our cannons and because this was the first time we had ever shot them we needed a little help from mr twilley. We were all really excited And we weren't actually aiming for anything at this point because it was only our first time shooting the cannon. Each team went down the line and took turns shooting their cannons. For most tables this was the first time they had shot anything out of their cannon. This was the case for us too.
After we had finally finished the entire project and built the entire cannon Mr. Twilley took us outside to test our creation. When we first got outside we didn't know what to do so he helped us. We used a tube that allowed us to pressurize our cannon and put as much pressure in as we wanted to. Our first test was pressured at about 65 and then with each test we increased and added a little more pressure. Our cannon shot really far and the entire experience was really exciting seeing as we had just spent a lot of months working on the project. Actually seeing it work was very interesting and cool.
This is our data of the shooting. We only had chances to shoot at 75 PSI. As you can see from the graph above, when the angle was higher for the post part the cannon ended up shooting the tennis ball further.
Reflection: Overall the project was quite enjoyable. I think it was really good for all of us to learn how to use some tools and some products that we didn't know about before. I also think the idea was very cool. I think that a lot of kids got really pumped and excited when they heard the words "Battleship" and "Cannon". These words are usually associated with a lot of reckless fun which is what a lot of people are into. I personally was very excited but also a little let down by this project. I loved everything we were doing and the entire build process was really fun but I wish we had some more freedom building a cannon. I think the fact that we were only building a base was a little less exciting and in a way somewhat easier. I think if we were tasked with building a cannon we might have learned more about design process and how certain things work. Also I think because each cannon was the same it limited some about of creativity because if we all had a working cannon the cannon would shoot it just wouldn't go as high as someone else whose base was made to shoot the ball at a higher angle. All in all, though, I did enjoy the project. I know particularly in my group when we were doing some of the activities there were a few people in the group who completely took over and wanted their ideas to be used and nobody else's. This made for a bit of a hard time considering some of us in the group were sitting off to the side not being listened to but in the end we got a product out which is all that matter. I will take what I learned from this project and in the next project completely take charge so I cannot be left out again and so my ideas will be heard and mean something.