BLOG ENTRY #6

 WELCOME BACK!!! This blog will cover the next part of our CA2, which is a ping pong ball launcher, and our final practical. So why not follow me as I bring you along my journey.

OPERATING PRINCIPALS AND MECHANISMS

So, what exactly is operating principals and mechanisms?? It basically means how things work. Every device and equipment are made based on working principals that fall under mechanical, electrical chemical and magnetism. Since we were new to this, Mr Chua gave us a chemical engineering example to help us understand this concept better.

• So lets say for a distillation set-up. What is the operating principals behind distillation??

• It would be based on difference in volatilities (boiling points) 

 So, after this example, we managed to have a better understanding of this concept and we move on to mechanisms. 

MECHANISMS

So, what's the difference between mechanisms and operating principals?? They sound the same right?? Well, mechanisms is basically something that enhances or improves the principals that it works on. For operating principals to work efficiently, mechanisms are often needed. So, back to our example earlier on the distillation column, what exactly is the mechanisms behind it?? That would be the trays in the column. Mr Chua then introduced to us the more common mechanisms that are being used in the industry. 

Mechanisms such as:

• Actuators

• Cams

• Gears

• Levers

• Ratchet

• Springs

Some of this I'm pretty sure we've all heard of and even seen it before such as springs and levers. After introducing to us the various mechanisms, we were then told to design a ping ping ball launcher that uses at least one of the mechanisms shared earlier and this would form a part of our CA2. My team and I got started on ideating for this ping pong ball launcher and we managed to come up with a design that we all found satisfactory.

This was our final sketch drawn using Visio

This is the more detailed version, with all the mechanisms drawn

This is how our ping pong ball launcher works

Overall, our design is rather simple and quite similar to most of the toy guns being sold, which was why we went with the design. With that, the lesson was rather informative and useful and with that, we are done with the ping pong ball launcher and we move on to the fun bit which is P4.

Practical 4: Cardboard Marble Game

Now, onto practical 4, the cardboard marble game. Upon hearing this, I was quite interested as we had done something similar to this back in P2, where we had to use corrugated cardboard to design something using cardboard joineries. However, this is slightly different as instead of cardboard joineries, we had to use the mechanisms that we learnt prior. On first look, it sounds quire fun as it is not related to any chemical plants of engineering concepts. But looks can be deceiving.

Obviously, there are a few requirements that we have to meet when making our game and here is the list of requirements that we had to meet:

⏵ The game has to keep the marble in continuous motion for at least 30 secs 

⏵It has to be made predominantly of corrugated cardboard
⏵It has to have at least one manually operated mechanism
⏵The structure cannot exceed 100cm x 100cm x 100cm

Mr Chua also allowed us to meet prior to this practical to discuss or even make a few parts of our game beforehand. However, my group failed to realise why he allowed us to do so as we did not know that this practical was not easy as it seems. My group managed to come up with an idea of making a roulette wheel using cardboard. It seemed doable in our heads and with that, we went into practical 4!!

On the day of the practical, Mr Chua also told us how this practical was going to be graded as it was slightly different to the other practical. 70% of the marks would come from him and 30% would come from those who played the game. There would be a QR code that would be next to our design and to those who played and enjoyed the game, they could scan the QR code and vote for the design. This was quite scary upon hearing as if the design was bad, 30% of our marks would be gone.

 He also mentioned that we had to do a mini presentation on our design, mechanisms and overall aesthetic. To see if it would make a marble last for 30secs of continuous motion, he allowed us to either do it during the presentation or we could film a video and show it instead.

With all that, we decided to get started on our roulette wheel since we only had 2hrs to complete our design. We started first on drawing the base of the roulette wheel. We decided on a 30cm diameter circle as we felt that it would be big enough

Next, we decided to make 2 smaller circles and this would make the spinning part of the roulette wheel which would allow the marble to spin. Here are the sketches for those.

In order for the marble to stay in the roulette wheel, we had to make a wall to keep the marble inside, preventing it from rolling out.

We then decided to cut ridges into the circle to let the marble fall through. However, it was at this point when Mr Chua decided to approach us to ask us about our design. When we told him about it, he seemed quite unsure if our design would work. He then told us why he felt that our design wouldn't work and after hearing that, what he said definitely made sense and we therefore had to come up with a new design. This was quite tough as we were already 30-45 mins into the practical and if we were to change design, we then had to start over with even lesser time. 

We decided to look up different and feasible ideas that we could make with our remaining time. Mid brainstorming, there were quite a few ideas being raised but we were doubtful if it could work as we didn't want to restart again. It was then on of my groupmates suggested to make a catapult. We all thought about it and decided to go with it and it seemed feasible and could make the marble roll for at least 30secs. And with that, we decided to get straight to work since we had limited time.

We decided to split up the work: 2 of us would work on the actual catapult itself and the other 2 would work on a structure to catch the marble after being flung from the catapult. My groupmate, Jeevan and myself decided to start designing the catapult.

Before the marble can be flung, it has to stay in the catapult for a while. So, we had to make a holder for the marble. We first decided to make the catapult before the pouch since we had to know the dimensions of the catapult so that we can design the pouch to fit.

Once that was done, we then proceeded to work on the pouch to keep the marble. We first had to sketch it out before cutting it out using a penknife.

While we were working on this, my other groupmates was working on the 'landing point' of the marble. They decided to reuse the circle that we made for the roulette and turn that into the landing point. They decided to cut a hole through the middle to let the marble fall through. They also decided to use the wall that we had made for the roulette and use it to prevent the marble from falling off when it lands.

Once the marble fell through the hole, it would just hit the floor and this would prevent it from meeting the requirement where the marble has to be in continuous motion for 30secs. Therefore, we decided to make 

a tunnel for it to fall through.

While all this was happening, our catapult was almost done. All that's left was with the assembly.

Before that, this is how our catapult turned out. Starting with the body,

To connect the body to the catapult, we decided to use skewers instead of glue or tape. This would allow it to move it back and forth.

Next, the base. We decided to use glue for the base so that it would be more stable and less flimsy

And with all that done, we can finally assemble the catapult.

The rubber bands that you see acts as a lever, allowing the catapult to move back and forth. The potential energy from the rubber bands also allows the marble to be flung further. 

Since most of the design is already done, we then decided to assemble the whole design together to see if it would work.

Once all the assemble was done, we then had to test if it allows a marble to move for 30secs continuously. By this time, we were already over the 2hrs limit for the practical and Mr Chua then told us to film the video of the product in action and upload it onto MS Teams.

With all that, we had to make do with what we have. It obviously doesn't look very aesthetically pleasing as there are lots of dried glue and tape everywhere, but for it being our second design, it definitely turned out much better than I had expected. We managed to come up with a new idea midway through the practical and ran with it so the results were definitely not the best but was satisfactory. Anyways, here is the mini presentation video that we filmed. (It was almost time for our next lesson while filming hence the background) 

And that's that for Practical 4. Here are some of my key takeaways from this practical. The most important one being to start planning instead of coming in cold. We definitely should have tested our original idea being the roulette wheel before coming for the practical. If we had planned for it, I feel that we might not need to change our ideas midway through. The fact that we were given the chance to plan beforehand should have been a sign of how hard this practical would be. Having a plan B would have also been helpful as we wouldn't need to scramble for ideas, resulting in time wasted. 

Overall, the experience was definitely not smooth but it was fun regardless. If not for my groupmates, we wouldn't have been able to get through this practical. It would have been impossible without them. 😁😁

This brings me to the end of this blog!! Thanks for making it all the way here and stay tuned for more!! See you soon!!😀😀