WASSAP MY BOIS & GALS, welcome back to Dr Bokana's blog. Previously we talked about my egg drop challenge and all the struggles I had faced when while doing the assignment. Today's blog is going to be more technical but there will be a surprise at the end regard another one of my atrocious practicals. I hope you enjoy my experiences and have a good laugh too.
So today we are gonna talk about Operating Principles and then move on to mechanisms.
Operating Principles
So what are Operating Principles ? In simple terms, it is how things function, they can be classified into many different variants such as mechanical, chemical, electrical and even magnetism.
To allow you bokanas to understand, a simple example would be distilation between 2 liquids
I am sure most of y'all know what distillation is, RIGHTT? Please say yes, if not I have nothing to say at this point. IF YOU DONT KNOW ALREADY, distillation is the process where 2 substances are separated from each other. And the picture above shows an apparatus commonly used in school to allow distillation to occur. In which situation can distillation be used in?
When both the liquids have different boiling points, the objective is to evaporate the liquid that has a lower boiling point and as the vapour passes through the cooling segment of the apparatus it condenses and collects in the bottom flask. This makes the difference in boiling point the operating principle of distillation.
Another example would be liquid - liquid extraction. This is a common process used to separate 2 liquids as well.
WAIT, if we can use distillation why would be need liquid - liquid extraction? This mainly used when the 2 liquids have similar boiling points. When they have similar boiling points, even when the temperature is precise to the higher volatile liquid, there is a possibility that the lower volatile liquid may evaporate as well. Making the final product impure.
Liquid - liquid extraction is mainly used when the liquids are immiscible to one another, meaning that they do not mix together. The best part is that when they do not mix, they tend to form layer which separate them according to the density, the liquid with lower density will be on top while the liquid with higher density will be below which makes separation easy. So what is this working principle of liquid - liquid extraction? It would be that they are immiscible and the difference in density.
I hope everyone understand what operating principles are about as the text part would be a little more intensive.
Mechanisms
Mechanisms? eh isn't this chem eng. Why suddenly talking about mechanism all? As well all know Chemical Engineering is about applying engineering into chemistry. So of course we gotta get into our engineering mindset and start with the concepts and stuff.
It is always important to find out the operating principle of any design you are using. And for your operating principle to work efficiently, mechanical movements are often required. Therefore, the addition of mechanisms.
Many chemistry student know mechanisms as the fundamental chemical processes involved in or responsible for an action, reaction or other natural phenomenon. However, in engineering mechanisms refer to the combination of rigid or resistant bodies, formed and connected so that they move with definite relative motions with respect to one another. In simpler terms, something that transforms forces and movement into a desired set of output forces and movement.
There are many examples of mechanism and I, your beloved Dr Bokana, shall show you a few examples and explain how they work to my readers.
There are 6 Essential mechanism use is functional prototypes
- Actuators
- Cams
- Gears
- Levers
- Rachets
- Springs
Actuators
This is an example of an actuator, it seems like a complex mechanism but basically all it does is convert stored energy into motion. Typically these stored energy are in forms or compressed air, electrical potential and liquid pressures. The types of stores energy could also be labelled according to their operating principles of electrical, pneumatic & hydraulic.
Cams
This mechanism works by rotating the pear shape shaft and coverts the energy produced a simple or complex reciprocating linear motion. Simply speaking, the pear in the center rotates to produce energy and this energy, similar to an actuator, can be converted into motion,
Gears
From the photo above, you can see that there are many different types of gears but they all work under the same operating principle where one of the gears are used to transmit torque and adjusts rotational velocity.
Levers
I am sure most of you all have seen a lever or hear of it before but not many of us understand how a lever works. The operating principle of a lever is to transmit and amplify force by fixing the input and output about a fulcrum, which also known as a pivot point.
Rachets
No I am not talking about the cartoon movie Rachet & Clack 💢💢💢
Reference for those oldies who don't know what Rachet & Clank is
An example of a rachet would be this, very similar to a gear but the main difference is just that the instead of 2 gears being used to produce energy a claw is substituted instead. The usage of a claw prevents the Rachet from going backwards as the claw locks in one direction allowing the mechanism to tighten.
Springs
Springs are a very commonly used term but there are actually many different types of spring available, similar to the gears, all the springs have the same operating principle of storing and dissipating energy when extend and compressed.
Ping Pong ball Machine ????
After learning about mechanism, we were told to produce a sketch of a ping pong ball machine. Somewhat like a gun where the machine can shoot out the ping pong balls. The hard part was that we were told to use one of these mechanism to produce this machine. It was very important that we made a designed a proper machine as it would be a part of our CA2.
Initially we wanted to use springs where we would compress the spring and when it expends the ball would shoot out. A very simple design but at that very moment, my group mate Dylan had thought of something he had seen on YouTube. This very idea would be used as our final design.
Very similar to this design, we wanted to reduce the size for us to use it on a ping pong ball. We also added an extension for the magazine of our so called Ping Pong Machine/Gun. This design was very effective as it allowed the ball to travel a long distance and it is commonly used in American Football for training purposes. The ball would propel far and the athletes would practice catching the ball before it lands. The wheels spin at a high speed which provides torque to the football which will then be converted into motion allowing the ball to travel far. What a brilliant way to adapt the typical mechanism taught in class. It may not be similar to the 6 essential mechanism but it still follows the same principles.
This was the initial design provided by our artist Ngo Van Anh, also know as Ngovapz. As you can see there are a few additions, like the magazine to hold extra ping pong balls and even handle for it to be used a gun. We decided to added a circuit to the machine by adding a trigger. When the trigger is pressed, the circuit will close and it would provide electricity to the wheels causing them to spin, once the ball is shot, the trigger is released and the circuit would be closed causing the wheels to stop prevent any unwanted injuries.
The picture below shows a more detailed design of the ping pong ball machine done by Dylan Low
Practical 4: Marble Game
This week's practical was a bad one 😢😢. It seemed roughly simple, all we had to do was produce a marble game made out of cardboard. I am sure we could come up with something easily. BUT there was a rule that the ball had to stay in motion for 30s at least. WHAT eh 30s is not a short amount of time leh. Don't scare me dei. Worst part it must be in constant motion sia AND cannot be bigger than 100 cm by 100 cm by 100 cm. Aint no way bruh.
I genuinely thought Mr Chua was trying to kill us, there is no way we could do it right. You know what, you're mostly right. It may not be our best work but at least we had fun.
Initially, we wanted to produce something like this but to our underestimation we had done such a good job.
We started off by making a platform for the marble game, hoping to produce a game which could stand up vertically
We also added a funnel to allow the ball to roll around which increased the time.
To be honest, we made something but it was not always completely in motion. But here's a video that explains how our game works.
As you can see in the video everyone was had already passed out mentally AHHAAHH but the it was not so bad.
In this video you can see how we used external momentem by our engine Antriksh which allowed the marble to stay in the course for more than 30 seconds. Making it somewhat of a success but producing our own marble briyani.
There were a few points that we took away from this practical, FIRSTLY never underestimate the assignment given and always prepare beforehand. NEXT, learn to work with what you have. As at the halfway point of the practical, many of us had lost hope but Antriksh made us maintain focus which helped us to at least complete the model.
And lastly a short video of us suffering while doing this practical
I hope everyone enjoyed this blog despite it being short. Stay tune for my final blog which will be up soon. It has been a pleasure writing this and I am glad we were given a task of writing a blog even if very little people actually read it. This blog reminds me of the nonsenses we did in class, and without this blog i would certainly forget these torturous yet wonderful days.
Yours faithfully,
Dr Bokana XOXO
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