During our lab sessions, I completed building the air cannon.

To begin, I selected the materials I needed. I found some plastic tubs and plastic sheets in the reusable plastics bin in the design lab; by reusing materials, I was able to reduce my environmental impact and use up old materials within the bins. I was able to procure a roll of elastics from the closets, which I later cut into three strips – two for the cannon, and one as backup.

First, I cut holes in the bottoms of the plastic tubs with a pair of scissors. I marked out the lines I needed to cut with a permanent marker taped onto a compass, then punctured the bottoms with my scissors. Afterwards, I traced out an outline of the grip on a piece of paper and cut it out. I brought that piece into the design lab and used it as a template for my grip. With the help of Mr. Diego, I cut out the grip on a piece of 2cm thick wood, sanded down the grip, drilled holes in the bucket and grip, and screwed them together with long Phillips screws. During the session, I learned several new techniques and skills. In order to drill holes in the soft plastic bucket, I had to press the surface against a hard piece of wood. To ensure that the screws did not break the plastic tub, washers were needed between the tub and the screw. To soften and smooth the edges of the grip, I originally planned on using sandpaper, but I was introduced to the electric sander and used that instead; the electrical sander was far faster and provided a smoother finish.

Next, I extended the barrel using the smaller tub, which was taped on. I realized that my original idea of modular barrel attachments was far too finicky, so I made an attachment using a piece of paper pressure-fitted onto the barrel. This helped decrease the barrel weight and allowed for easier construction of modular attachments.

Finally, I attached the elastics and plastic sheet on the back of the air cannon. I realized the original plastic sheet selected was far too thick, so I found another thinner sheet in the reuse bin. I mostly used duct tape for the attachment process, as it was the most visible type of tape. Any other would have been too hard to spot and would cause a more difficult repair down the line, when the plastic sheet inevitably breaks. Unfortunately, my idea for a handle to pull back the elastics was not feasible as it would cause far too much stress on either the elastic bands or the plastic sheet, or cause an air leak.

 

The air cannon, as its name implies, shot air. While the range was not great, and the amount of air launched was barely enough to knock down some paper, it nonetheless shot air. The air can be felt from over a meter away, but the accuracy can only be described as terrible. Often, only a third of the shots hit, even while aiming in the same direction. It was precise, but not accurate. Also, barrel attachments can be made out of paper and pressure-fitted onto the front. This allows for quick changes to the barrel, but the additional piece in the front often decreased the amount of air coming out and therefore the effectiveness of the air cannon. The grip, on the other hand, was very nice. Nobody complained about its size or shape. The edges were sanded down to prevent them from cutting into the hand, and the grip was slightly angled for better ergonomics.

 

I tested the air cannon on my friends with their consent. Also, Mr. Walton tested it out when he saw me with it.

Much of the feedback were about the accuracy and range. While the air was noticeable from a range up to a few meters, it was hard to aim the cannon. Often, it took multiple attempts just to hit someone at a range of one meter. According to Peter, the best way to aim was to have the target stand still and constantly adjust the direction of the cannon until the air hit. Henry also mentioned that the grip moved during firing. While durability was not a concern, the shaking barrel was one of the culprits behind the inaccuracy. In a somewhat successful attempt to solve the issue, I added hot glue between the barrel and the handle. Mr. Walton thought the duct tape was a bit ugly and detrimental to the aesthetics.

 

Given the opportunity, I would make many changes to the current design. While reusing plastic tubs is environmentally friendly, a 3D printed barrel would be far more durable and versatile. I would add some reinforcements in the back so the barrel would not squish as much during firing. The current barrel attachment system is subpar; a 3D printed barrel would allow for a system similar to the original design plan. I would keep the current wooden grip design, as it felt satisfying and sturdy. Finally, instead of using random, small strips of duct tape, I would use larger pieces placed consistently around the back so it appears somewhat like a pattern while still keeping the advantages of duct tape.