This year in IB Stem 2, we immediately delved into our first project at the start of the year: building a tennis ball cannon and functional turret base. The main material we could use was wood, so our turret had to have an efficient, practical design emphasis. Lets get right into it:
Some of our first brainstormed designs for our project
We started this project in September and began brainstorming ideas for our task of building a proper cannon support system to allow for various trajectories of firing. We started out watching youtube videos and looking at pictures of turrets from video games to get inspiration for our design. We came up with a special gear that would rotate around and a pulley to adjust trajectory angle. This design took us a long time to come up with however and everyday we were brainstorming on how to perfect our design. We decided today that we would like to attempt to further plan our design for our base, as well as figure out what type of stabilizer for the base we would like to use in our final design. This early stage planning will help in the future to make our design cost effective but strong and stable so that it doesn’t bend or twist.
One of our templates that was cut out with the shopbot and used to assemble our base.
The final design of our base without the cannon in onshape.
Our design for our firing mechanism for arduino. In the end we did not utilize any arduino for the firing mechanism, however we were ready and able to if needed.
We went into discussion for the design for the base and have come to a few conclusions, the most practical being a lazy susan type device with an attached elevation system, though it is currently unclear what type of design we would like to go with. Though we are still unsure as to what complications may occur with this design, we would like to choose a table with some type of lazy-susan type device on top, however the decision is still up to debate as we haven’t completely gone over the logistics of the design. Unfortunately due to the several contradicting ideas that didn’t result in furthering the project, ranging from anywhere between a design with a tank-type movement system to a design with a new type of cannon (which is not allowed) brought up by the group, our brainstorming occupied the entire class leaving little room for discussion on the type of design we would like for our stabilizer. We were planning to use some sort of glue for the stabilizer, but we found out late in the class that we aren’t allowed to use glue. We were able to quickly brainstorm a new idea, but we do not have the time to create it on onshape. Our next steps are to create the design for our stabilizer on onshape and make a prototype out of cardboard to see how well it works. We will then fix it until it’s perfect before making the full-scale model.Today we have begun designing our prototype in Onshape. We have focused on one idea that will be a table fixed into the ground, along with a “lazy susan: on top. Our goal today was to finish our Onshape design, yet due to time limitations we were unable to finish. Instead of wasting idle time, we took some inspiration at finished turret designs on google and tried to widen the feet of our turret base to provide more traction and thus more stability. Next class period, we hope to finish designing our first prototype in Onshape. All we have left to do is to finish designing our elevation mechanism, which is two hinges that the cannon would slide into to provide a smooth manipulation in altitude and shooting angle. The one flaw in our design that we have yet to correct is to keep our cannon in a fixed position. We hope to finish designing and correcting our flaws in the next class period.This class period we to finalized our first prototype. We did this by finishing our basic elevation mechanism. This mechanism is just two hinges that hold our cannon into place. We still haven’t fixed our elevation flaw. With our current design, our cannon is able to rotate and elevate, but we cannot keep the cannon elevated at a fixed position yet. We have thought of some ideas to fix this though, but none of them seem realistic and efficient. One of these was to have a rope attached to the top of the barrel that would run down to the back of the “lazy susan” where it could hook onto a fixed point that would fix the barrel at a specific degrees. The problem with this design is that this would only allow the cannon to elevate at fixed positions, but we want to have our cannon elevate at any postilion. We are in the works of currently brainstorming another elevation idea. This one is some sort of platform that guides the cannon up at a fixed point. Are ideas are still in development and nothing is final. Since our current design is We were somewhat successful with our design, because v installed two hinges which the.
The ShopBot outline and cutting out the pieces of our outline (1 of 2 boards)
The final product in the process of gluing and final modifications, specifically the stabilizers.
The final steps of our plan came into place; we had to cut our pieces together and assemble the structure. This process was very smooth, all we had to do was sand everything then glue it. The only issue we encountered was the rotating hexagonal system and a simple fix was used. All we did was put a spacer between each input of the hexagons and the length was corrected to make the spindle fit perfectly. We took our design out and fired at 3 different angles. Each angle fired fine without error, so we put our cannon to the test and tried to hit a specific target. The wind kept messing our trajectories up so our cannon failed over 10 times trying to hit the target. In the end, though our project was successful, functional, and patriotic.
Joshua Byron Dial in the process of firing our cannon. The primer on the mount of the cannon is evidence of the last minute fix we had to use to ensure our cannon would fire. We forgot to glue one of the caps on the cannon and thus there was no airlock seal and the cannon would not fire. It was not an issue, however as we quickly primed and glued the cap on and fired our cannon smoothly
Our data was limited to 3 angles for 3 trials each, due to restricted time outside firing our cannon.
This project took us several months and a lot of blood, sweat, and tears was put into it (more like time and mental frustration). We started out with looking at designs of turrets on the internet; took our inspiration and ran with it until we reached a first design; tirelessly edited the project until we reached a satisfactory prototype; daringly printed our project out and ran with the kinks; after numerous quick fixes and glue cover ups we had our final design and it worked pretty well. Each trial with our cannon was pretty accurate and similar to other trajectories of other trials. We were the closest group to hitting the target in the battleship phase of testing. This accuracy and precision is all the evidence we need to prove our project's worth. Always remember to find a process, trust it, and run with it till the finish line, because if you do so you will be rewarded handsomely- as we were in this project.
We trusted the process and it rewarded us generously.