Intro to Mechanical Engineering
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Episode Show Notes
What is mechanical engineering? Engineer Sadhan Sathyaseelan joins the show again from The University of Texas to wonder out loud about all the important aspects of this classic engineering field. This is a continuing series of conversations introducing the fundamentals of different engineering disciplines. In this episode on mechanical engineering, we talk about thermodynamics, motion, manufacturing, mechatronics, design methodology, machine elements, and more.
Our opening music is called “Soar,” and our closing music is called “Polar,” both by artist Chris Pop, used with permission. You can find more music by Chris Pop on SoundCloud.
Subscribe and leave episode reviews wherever you get your podcasts. Support Pios Labs with regular donations on Patreon, by purchasing digital teaching materials at the Pios Labs curriculum store, or by buying a copy of the reference book Engineer's Guide to Improv and Art Games by Pius Wong. You'll also be supporting educational tools and projects like Chordinates! or The Calculator Gator. Thanks to our donors and listeners for making the show possible. The K12 Engineering Education Podcast is a production of Pios Labs.
Pius Wong 0:01
Get your introduction to mechanical engineering on today's episode of The K12 Engineering Education Podcast.
Pius Wong 0:16
There was a previous episode called "Engineering 101" where we gave an introduction to engineering in general. Well, we are back with special guest Sadhan Sathyaseelan to get an introduction to mechanical engineering. Sadhan is a mechanical engineering PhD student at the University of Texas at Austin, and he's going to help us learn a little bit today.
Pius Wong 0:42
We're learning about mechanical engineering.
Sadhan Sathyaseelan 0:44
Yes. We are going to go through what mechanical engineering is.
Pius Wong 0:48
That's really huge though, right?
Sadhan Sathyaseelan 0:50
That is a big, big, big topic.
Pius Wong 0:53
So maybe we're going to start at, like, the top of the hierarchy.
Sadhan Sathyaseelan 0:57
Pius Wong 0:58
So in college, if you were to go to college for a mechanical engineering degree, there's like an orientation, sometimes -- I know that I had one. And they give you that overview. They have, like, a faculty member or counselor, whatever, and says, hey, these are all the things that you could follow. It's like a board game.
Sadhan Sathyaseelan 1:16
Pius Wong 1:17
Like the Game of Life. It tells you that path that you've got to follow in order to get --
Sadhan Sathyaseelan 1:21
Literally the game of life.
Pius Wong 1:22
Yeah. So what's on this board game called mechanical engineering?
Sadhan Sathyaseelan 1:26
Okay, so there's a lot here. I think we should first break down what mechanical engineering is, in terms of, what are the different topics that's in there. I think each of these topics might require its own episode. But for now, let's approach -- I think it'd be ideal if we approach mechanical engineering as how it's taught in the university, how its approached at a university. And then we can we can branch off, what are the actual conceptual ideas, and what are the things that they learn as prerequisites, and what are the things that they learn just as kills that's not exactly mechanical engineering. Would that be a good way to approach it?
Pius Wong 2:08
I think that's real hardcore.
Sadhan Sathyaseelan 2:10
Why is it hardcore?
Pius Wong 2:11
No, that's good. Well, it's like, dang, we're putting people through college here. But in a fun way. No, that's good. Once you use the word "prerequisite," I was like --
Sadhan Sathyaseelan 2:20
Oh my god. Yes.
Pius Wong 2:21
I'm in undergrad. So the prerequisite to listening to this podcast is that you have to, I guess, understand English.
Sadhan Sathyaseelan 2:28
Pius Wong 2:28
And understand things that you see with your eyeballs.
Sadhan Sathyaseelan 2:32
Pius Wong 2:34
Sadhan Sathyaseelan 2:35
No? Maybe touch. Yes, temperature. If you take a shower, that's fluid mechanics.
Pius Wong 2:43
If you take a shower, let's hope. There's a biological system called the vestibular system.
Sadhan Sathyaseelan 2:49
What is that?
Pius Wong 2:50
It's inside your head. Behind your ears, there is this little tiny squiggle-looking thing, a bony structure filled with liquid, and it detects when you're upside down and moving all around.
Sadhan Sathyaseelan 3:00
Oh balance, okay.
Pius Wong 3:02
It's another sense that you'll be using.
Sadhan Sathyaseelan 3:04
Pius Wong 3:05
So if you're a dancer or if you play sports, maybe you'll be able to relate to some of the stuff we talk about.
Sadhan Sathyaseelan 3:11
Hopefully we will relate it to most people, right?
Pius Wong 3:16
Sadhan Sathyaseelan 3:17
We'll also talk about what math you need to learn if you want to take it as a profession. But if you're just interested in, you know, just what's in there, I think we can just quickly go through the math part.
Pius Wong 3:31
Sadhan Sathyaseelan 3:32
Okay. Essentially, what is the split?
Pius Wong 3:35
The split. What do you mean?
Sadhan Sathyaseelan 3:36
Yes. In the hierarchy of --
Pius Wong 3:38
Like the categories --
Sadhan Sathyaseelan 3:40
Categories that you have to learn mechanical engineering.
Pius Wong 3:42
Well, to me, mechanical -- The word mechanical, it sounds like mechanic.
Sadhan Sathyaseelan 3:46
Pius Wong 3:46
Which is like, I go to the guy who helps me fix my car. They use tools. They fix a machine. They deal with things that move.
Sadhan Sathyaseelan 3:57
So mechanics. Mechanics is definitely a like a big branch. What does it deal with?
Pius Wong 4:04
Isn't mechanics the study or the field of moving things?
Sadhan Sathyaseelan 4:10
And also stationary.
Pius Wong 4:12
So in what ways? Why stationary? I have to be reminded of this myself. I'm not, like -- I'm like, Oh, I'm being very Socratic method. No, I actually don't know, Sadhan.
Sadhan Sathyaseelan 4:22
Okay, so this is -- I guess an approach would be: One big topic that we learn as engineers, as mechanical engineers, is mechanics itself. And mechanics is actually a physics concept. It's just learning about forces acting on bodies.
Pius Wong 4:44
Not like, people bodies --
Sadhan Sathyaseelan 4:46
It's people bodies, too. Objects, tables, chairs, you know? Effect of those things. If you're talking about liquids, you're talking about the movements of those liquids.
Pius Wong 4:56
Sadhan Sathyaseelan 4:57
Yeah. Throwing a ball, that's also some certain kind of mechanics. So I guess anything that's moving is definitely in terms of mechanics, what's happening in terms of its mechanism.
Pius Wong 5:10
But you're right, maybe not moving. Maybe you've got so many forces on it.
Sadhan Sathyaseelan 5:13
Forces acting on one body, it is in balancd. So I guess that's statics.
Pius Wong 5:18
Like me sitting down lazily. There's gravity.
Sadhan Sathyaseelan 5:21
Pius Wong 5:22
And so it's jogging my memory. I remember learning about forces, or dynamics, and statics, stuff like that. These are some jargon words, right?
Sadhan Sathyaseelan 5:34
It is. But conceptually, I guess it's all about forces acting on bodies, and what are the effects of that?
Pius Wong 5:43
It sounds like -- forces acting on bodies sounds like it could go wrong after --
Sadhan Sathyaseelan 5:48
Pius Wong 5:50
Well, like you know.
Sadhan Sathyaseelan 5:52
Forces acting on anything, how about that?
Pius Wong 5:54
Sadhan Sathyaseelan 5:54
Pius Wong 5:55
Sadhan Sathyaseelan 5:55
Pius Wong 5:56
Sadhan Sathyaseelan 5:57
Pius Wong 5:59
Space? You can't have a force on a vacuum, huh? Because there's nothing there to have a force on, right?
Sadhan Sathyaseelan 6:05
Anything that can take a force is what's relevant, right?
Pius Wong 6:08
Any body that can take a force --
Sadhan Sathyaseelan 6:10
Yeah, I guess it's fundamentally --
Pius Wong 6:11
I can't take any forces, Sadhan, so don't punch me.
Sadhan Sathyaseelan 6:15
Pius Wong 6:16
So okay, we're going to learn about forces.
Sadhan Sathyaseelan 6:19
Pius Wong 6:20
Sadhan Sathyaseelan 6:21
Yeah. Or stationary.
Pius Wong 6:24
Sadhan Sathyaseelan 6:25
So I guess it's about material bodies.
Pius Wong 6:28
Okay. Materials, that's a key word there.
Sadhan Sathyaseelan 6:31
Solid state, liquid, gaseous state, it doesn't matter. If it's a material, and there are some forces acting on it, even if it's in absolute equilibrium, or absolutely balanced forces, I think that the entirety of that is talked about in mechanics.
Pius Wong 6:48
Yeah, we've got to have a whole episode on that.
Sadhan Sathyaseelan 6:49
Oh, yeah, of course. This is not -- There's so many things in mechanics that can branch off. Hopefully we'll touch upon those things.
Pius Wong 6:58
So a mechanical engineer has to know this because there may be making stuff that apply forces or that take forces.
Pius Wong 7:06
Yeah, moving, right?
Pius Wong 7:08
Sadhan Sathyaseelan 7:08
You just described the automobile. A mechanic an automobile. Everything's moving in there.
Pius Wong 7:14
Maybe I knew what I was talking about. You also said something about material forces. And I like the word material, because I think materials are a big subject in mechanical engineering, too.
Sadhan Sathyaseelan 7:25
Yes. So I think it's just because we have so many different materials on earth, and each of them behave differently. In terms of behavior, we mean that, if you drop a piece of, say, a metal, and if you drop a piece of glass, when they hit the floor, they behave differently. And this is a very simple example of what it is, but all those different materials have all these different properties that they have. And I think the idea of learning that is so that you know: what are the different materials we have? And how do they behave? And what can they do so that we can use it the way we want?
Pius Wong 8:13
Yeah, like, why don't I make windows out of aluminum? Or why don't I make cars out of glass
Sadhan Sathyaseelan 8:19
Exactly. So I guess that's what essentially learning about materials is. So what else is there?
Pius Wong 8:28
I don't know. I guess it's involved with chemistry and biology, too, coming from the biomechanical side. There's this like -- When mechanical engineers have to make stuff that people use, or that living things use, you've got to choose materials that won't attract bacteria, or that won't poison people. So there's that as well. Like, we've got to think about strength of materials, yeah, and whether they shatter or they are easy to bend, but also, like: Will they cause my arm to fall off? Or will they break off into a million pieces in my body? That's bad too. So it's like, there's lots of different things.
Sadhan Sathyaseelan 9:05
I just thought of another thing, in terms of material engineering. How big the field is, just to get a quick look of that. You know, the the boom of 3D printing, specifically, laser sintering, selective laser sintering, where essentially the technology is just like a printer, like a regular household printer where it sprays ink in a specific pattern. It's a very similar thing, except that, instead, you have a thousand pages printing one after another, so you have a three dimensional object. That's exactly what's happening. And the entire research -- an entire PhD's research was to find the right materials that they can use, and they found some nylon compound that works best.
Pius Wong 9:55
You can print layer by layer without it falling apart or melting or whatever.
Sadhan Sathyaseelan 10:00
It melts to fuse together.
Pius Wong 10:02
It melts in just the right way.
Sadhan Sathyaseelan 10:04
Pius Wong 10:04
They engineered it. There you go.
Sadhan Sathyaseelan 10:07
That's a good example. That's awesome. Thinking about -- Talking about temperature, heat -- That's a big field in mechanical engineering.
Pius Wong 10:16
See, people might not think that, though. Heat -- They might think, oh, heat is energy. Heat is like -- has nothing to do with moving parts. So some people might think that.
Sadhan Sathyaseelan 10:27
Hmm, it is mechanical engineering.
Pius Wong 10:28
But you're wrong. [laughs] Sorry, but yes, it is mechanical. But why? Why do mechanical engineers care about heat and energy?
Sadhan Sathyaseelan 10:38
Pius Wong 10:40
And that's the end of our episode. [laughs]
Sadhan Sathyaseelan 10:43
End of my expertise.
Pius Wong 10:44
My thinking is, like -- I guess I'm going to go back to the car example. I mean, cars are run off of energy.
Sadhan Sathyaseelan 10:50
Pius Wong 10:50
To get those wheels moving, you're not going to hand-crank it, you know? Like, this is not the Flintstones. You have to get the energy from somewhere.
Sadhan Sathyaseelan 10:59
Pius Wong 10:59
Meaning, when I want to power my awesome Toyota Corolla, I need to go and get enough gas to power it.
Sadhan Sathyaseelan 11:08
Okay, so that's gas, but this is the study of temperatures, or heat and cold.
Pius Wong 11:13
Right. So someone had to create that engine so that it burned my gas in such the right way so that doesn't burn my entire car, but it also will power the engine inside to start moving the -- or start rotating my tires.
Sadhan Sathyaseelan 11:28
Okay, so by the way the field of studying those things is called thermodynamics. It's a huge field that comes under mechanical engineering.
Pius Wong 11:38
And it's another class in college.
Sadhan Sathyaseelan 11:40
Yes, definitely. I think it's more than one class. You take a couple of classes that you learn --
Pius Wong 11:45
Grad school, undergrad, yeah.
Sadhan Sathyaseelan 11:47
Well, even in undergrad, I think there's a class on thermodynamics, and there is thermal systems. Different universities approach it differently. Essentially you're learning about how heat behaves.
Pius Wong 12:00
Where heat goes, like if I put a hot cake on my table, how long is it going to stay hot, or something?
Sadhan Sathyaseelan 12:09
I wonder if thermodynamics is a field -- It is, because, again, in my thematic view of this entire podcast is: engineering is not a new field. It dates back. Human evolution and engineering go hand in hand. And I wonder if if we studied thermodynamics in a huge way because we are so -- our evolution has been so intertwined with heat and from sun.
Pius Wong 12:41
Yeah, there's that classic story in a whole bunch of cultures, histories about discovering fire, quote unquote.
Sadhan Sathyaseelan 12:50
Pius Wong 12:50
Or that Greek mythology of stealing fire from the sun or something. The guy whose wax wings melted. I don't know my Greek mythology that well.
Sadhan Sathyaseelan 12:58
I didn't know the Greek mythology, but I do understand.
Pius Wong 13:01
Discovering fire -- so fundamental, so primal. So you're right. I think I might have said civil engineering, some experts say is the oldest one.
Sadhan Sathyaseelan 13:10
It seems like thermal engineering.
Pius Wong 13:12
Yeah, if they measured it. If they measured fire. I know people worshiped fire. People thought about it as a mystical thing. We light candles in church, but like, when did fire and heat and energy become a thing that people measure and harness and use and predict and use math on it?
Sadhan Sathyaseelan 13:28
I feel like, so when man invented fire, if you wanted a bigger fire, he needs to put ten wooden logs in it. If you move you want a small fire, he needs to put like five logs in it. I think it's an intuitive understanding of these thermal -- how heat behaves over time.
Pius Wong 13:46
Or cooling. They were doing similar thinking.
Sadhan Sathyaseelan 13:50
So I think maybe we already have a very good grasp of how thermal systems behaves.
Pius Wong 13:58
Yeah, hot stuff goes -- People know that usually, where does the heat go when you put the hot thing down.
Sadhan Sathyaseelan 14:05
Exactly. I guess this is like -- thermodynamics is studying all of this in a much more molecular level, in a much more -- we understand a lot better three laws of thermodynamics, which we will talk about in terms of just conceptually in the future episodes. It'll be awesome to talk about all of those things.
Pius Wong 14:25
Oh man, there's so many topics.
Sadhan Sathyaseelan 14:27
And I bet these -- It's like so intuitive. It's not like -- hey, why are people spending so much money on it?
Pius Wong 14:33
Not as intuitive as I'd like, but like, especially if you go to the biological side of things --
Sadhan Sathyaseelan 14:39
Yeah, you're right. Let's just bring on the whale.
Pius Wong 14:44
The whale being thermodynamics.
Sadhan Sathyaseelan 14:45
Pius Wong 14:46
What else do we still learn?
Sadhan Sathyaseelan 14:48
Okay. So we talked about mechanics. We talked about materials. We spoke about thermodynamics. But I think we should also break into mechanics, because mechanics is -- You mentioned it's also about -- Well, I guess maybe we covered everything.
Pius Wong 15:05
Forces and stationary, static stuff.
Sadhan Sathyaseelan 15:09
Pius Wong 15:09
And there's like -- if we made a Venn diagram of all this, there'd be intersections as well.
Sadhan Sathyaseelan 15:13
Pius Wong 15:14
We talked about the strength of materials, how beams break, for example. Explosions and how things fail. I think that's super interesting to watch. There's a bunch of YouTube channels where you can watch things breaking. There's a whole class or a whole field of studying that in mechanical engineering. You know, there is another thing that you made me think of when you said thermodynamics, and we talked about energy. Another type of energy, I guess, is electrical energy. And I know we're doing mechanical engineering, but --
Sadhan Sathyaseelan 15:44
No, it's a big field in mechanical engineering.
Pius Wong 15:46
Today, especially, especially today.
Sadhan Sathyaseelan 15:48
Pius Wong 15:49
There's circuits and electricity and all that stuff involved.
Sadhan Sathyaseelan 15:53
Basic electronics, at least.
Pius Wong 15:54
Yeah. So I'm wondering, like, how far should we go in talking about circuits or mechatronics or robotics.
Sadhan Sathyaseelan 16:03
I think it is covered in a typical mechanical engineering curriculum in its basics, but I think, when I look at it, you learn a lot about motors. And, you know, it's --
Pius Wong 16:18
You sound disappointed.
Sadhan Sathyaseelan 16:19
No, it's not disappointing, but it's essentially mechanical in nature. Electricity to move things. But a motor is a mechanical device. It's electromechanical.
Pius Wong 16:30
Yeah, that's a good point.
Sadhan Sathyaseelan 16:31
So I think even if electricity is -- electronics is -- not electronics, what is the word for it?
Pius Wong 16:40
Sadhan Sathyaseelan 16:41
Mechatronics. Okay. Mechanical electronics.
Pius Wong 16:43
We'll have a whole episode about it.
Sadhan Sathyaseelan 16:44
Okay. Yes. mechatronics is definitely a big part of mechanical engineering.
Pius Wong 16:49
You taught a little bit of that class.
Sadhan Sathyaseelan 16:51
I have. I taught it for one semester. at UT. It's fun, because it kind of strays a little bit away from your typical mechanical engineering hands-on, material, you know, tangible things. A little more into -- it's a bit little magical.
Pius Wong 17:09
A little more abstract. More magic, yeah.
Sadhan Sathyaseelan 17:12
Yeah, more magic.
Pius Wong 17:12
To the Harry Potter of our mechanical engineering --
Sadhan Sathyaseelan 17:15
A little more of the molecular phenomena.
Pius Wong 17:17
Magnets, and things that we see.
Sadhan Sathyaseelan 17:19
Fields. That's more conceptual.
Pius Wong 17:20
I can't see the electrons, so they don't exist. So, okay.
Sadhan Sathyaseelan 17:24
No, they do exist.
Pius Wong 17:25
I guess we'll have an episode about that.
Sadhan Sathyaseelan 17:26
Yes, that's definitely a big --
Pius Wong 17:27
I have a lot to say about that.
Sadhan Sathyaseelan 17:29
Okay, that's awesome. You built a bunch of robots. That I know.
Pius Wong 17:33
Oh, well, yeah. So I had mentioned I was supposed to have studied robotics in grad school. And I did, to some degree, but I didn't really continue it as much. And I feel like robotics is another one of those things that's a mix of mechanical and electrical engineering, and it's related to mechatronics. So maybe we can touch on that there. It's all about 3D motion these days.
Sadhan Sathyaseelan 17:55
Pius Wong 17:55
And putting a bunch of motors together in a predictable way and programming it and energy usage, and it's very interesting. But we'll save that for later. Hey, I'm also thinking about design. Speaking of robots.
Sadhan Sathyaseelan 18:09
Ooh, that's a huge topic.
Pius Wong 18:11
We didn't even talk about that. I'm surprised we didn't say that first.
Sadhan Sathyaseelan 18:12
How did we not miss that? Okay, wow.
Pius Wong 18:15
What's design, Sadhan? What is design?
Sadhan Sathyaseelan 18:17
Oh my god. Okay. I'm going to just tell a story. I'm not going to talk about what design is. I'm just going to tell a story. So I did my undergrad in India. You know that.
Pius Wong 18:29
We had a whole podcast talking a little bit about it. Yes,
Sadhan Sathyaseelan 18:31
Yes, India and the US. Folks should listen to that. It's a huge, completely different way of approaching things. But I remember in my final senior year, in India, we were -- I mean, I guess it's everywhere in the world. As engineers you're supposed to do a project. So the project is: We were designing something. Let's just leave it at that. We were designing something.
Pius Wong 18:57
[laughs] It sounds really suspicious now, but --
Sadhan Sathyaseelan 18:59
Oh, no. Okay. So let me then put it out.
Pius Wong 19:02
Just make up something. We were designing another --
Sadhan Sathyaseelan 19:04
No, this is not making up anything. Essentially what me and my team were designing was -- we were making a robotic hand that can write letters.
Pius Wong 19:15
Sadhan Sathyaseelan 19:16
And the script, specifically -- we were trying to make it right Tamil scriptures, and Tamil is a language spoken in southern India. It's one of the oldest languages spoken. And the script has a lot of curves in them. It's curvy. And it's actually very interesting why they are the way they are. But it's curvy nature. And it in order to get it to write -- it was a problem, and we were trying to solve that problem. But the experience of tackling that problem in India was so hard because -- because there was not a very good structure in place, in terms of how to approach the problem.
Pius Wong 20:02
Like nobody taught you --
Sadhan Sathyaseelan 20:04
Pius Wong 20:05
-- how to design something design.
Sadhan Sathyaseelan 20:08
They taught us how to design components, but how to approach the design problem was not taught. Yeah, there's two approaches to -- What I'm talking about is the design methodology here. How do you approach a design problem? And it felt like we were left in the middle of the ocean with no direction. And we had to plunge in. And we didn't know if the design we did was the optimal or terrible. We had no idea. It was just like, Oh, this solves the problem. And that's it.
Pius Wong 20:38
So you actually did it, though?
Sadhan Sathyaseelan 20:39
More of intuition than anything else. But and then after that, I came to UT, and I was so surprised to find that there's an actual field called design methodology. Not design. That's a different thing. And we'll talk about it. But design methodology. There's a specific approach on how to approach certain problems and come up with the most justified and optimal solution. And I ended up making it my research. I did my thesis on that. I TA -- TA is Teaching Assistant -- I teach or support teaching that specific course at UT, the senior design project. So design brings a lot of memories for me. But there's one part of design -- You can talk about it.
Sadhan Sathyaseelan 20:39
I don't have much to say -- like, that's a good story. I think that you remind me -- As everyone should know, the University of Texas at Austin -- I mean, I think their design program in the mechanical engineering department is really great --
Sadhan Sathyaseelan 21:43
Pius Wong 21:43
-- in that respect. Because like you -- I mean, we had a capstone project where we were supposed to design something back in undergrad in our last year before graduating, and yeah, they kind of just throw you in there. Now I agree that, like, I didn't know what the optimal design methodologies were. I didn't know what these tried and true and studied strategies are to come up with a good solution in the fastest, most efficient way. And I might complain about that experience, but looking back, I actually like that I had the chance to design without any guidance first, so that when I finally learned these methodologies later --
Sadhan Sathyaseelan 22:26
Pius Wong 22:27
-- I saw the difference in what I used to think, and I saw, you know, these other methods that other people have developed. And I was like, Oh, I see the need for these methods. Because I wonder if, like, if I had been taught some of those methods back then as a senior or something in undergrad, if I would have even appreciated or understood why I'm learning these things. So I think what I really take away from that is, I would hope that anyone who is trying to learn engineering and how to design a solution, that they try designing something just on their own, without any guidance. Kind of unstructured, kind of like we had, but do it at a younger age.
Sadhan Sathyaseelan 23:10
I never thought about it that way. I think that's a --
Pius Wong 23:11
Just to have a reference point.
Sadhan Sathyaseelan 23:13
Yeah, I think that was the only reason I was able to appreciate it as much as I did.
Pius Wong 23:19
But in any case, I totally agree. So that's all I had to add.
Sadhan Sathyaseelan 23:22
Awesome. So the other part of design -- this was like more of design methodology. So there are certain mathematics principles that are, like, already established. When you're -- Let's say you're trying to design a gear. A gear is like a wheel-like structure with the teeth on the outside. And there's like a number of teeth in there. So how do you know what number of teeth to put in so that they're not slipping away?
Pius Wong 23:45
-- how many teeth go around this size radius or whatever?
Sadhan Sathyaseelan 23:51
So it's already it's already been figured out.
Pius Wong 23:53
Is that Machine Elements?
Sadhan Sathyaseelan 23:55
Pius Wong 23:56
So I never actually -- So there's a class in the University of Texas undergrad called Machine Elements that mechanical engineering majors have to take. I never took a class like that. I also was a bioengineering undergrad.
Sadhan Sathyaseelan 24:06
That makes sense. Yeah.
Pius Wong 24:07
But it would have been a class that I would have wanted to take, looking back, because I ended up doing that in my workplace later. I had to build mechanical test structures, and it would have been great if I learned so much stuff that mechanical engineers are supposed to learn.
Sadhan Sathyaseelan 24:23
No, no, that makes sense. I mean, I totally see why this is so irrelevant. Okay. So when you when you look at the mechanical elements, you're looking at gears, right? Gears, where is it used? In the car transmissions, you use gears. Or in big machines you use gears. Looking at belt systems, were in big machines you're using belt systems. You look at cams. It's used in engines.
Pius Wong 24:46
Anything to transfer motion and forces around to different places. Okay.
Sadhan Sathyaseelan 24:51
And it also, like -- I think it's a very valid name. It's called machine elements, because they're not exactly -- they're not a system by itself. They're part of a bigger machine. So these are small elements. And these elements are not something you design from scratch. There are already established mathematics that's involved in there. We call it design. But essentially what you're doing is, you're figuring out the best gear to use. You're figuring out the best shape of the cam to use.
Pius Wong 25:20
Sadhan Sathyaseelan 25:21
So it is design in one way, because there are so many possibilities. So that makes sense in the context of mechanical engineering, because this is essentially working with a lot of machines. But it does make sense in terms of biological systems. They're kind of irrelevant.
Pius Wong 25:38
It depends on what you're doing. Bioengineering would be a whole -- really long set of episodes that would irritate me --
Sadhan Sathyaseelan 25:45
But I'm just curious. Just quickly, you know, what do you learn instead of that?
Pius Wong 25:51
Instead of? Oh, I mean, there's way more time spent on biological things. Like we had to take way more chemistry, genetics, biochemistry, stuff like that. And then -- genetics, by the way, one of my favorite classes. It's the most mathematical of all the biology classes, other than bioinformatics, which is more programming and stuff like that. But then we also had to take -- In bioengineering, you could choose different specialties within bioengineering. It's like majoring in a major.
Sadhan Sathyaseelan 26:21
Same thing in mechanical engineering.
Pius Wong 26:22
Yeah, exactly. And one of the concentrations, we'll call it, was biomechanics. And so I could have done that. Another one was biomaterials. Those are the two ones that I think were the most related to mechanical engineering. Biomechanics was about, you know, forces, statics, dynamics, but like, in organic systems, and biomaterials might be about designing artificial hearts or something. Like instead of designing aerospace materials made out of plastic and metal mixed together and ceramics, instead, you're designing tissues made out of cells, mixed in with polymers mixed in with circuits, that kind of thing.
Sadhan Sathyaseelan 26:59
Pius Wong 27:00
But you still had to worry about the same mechanical properties and all that stuff.
Sadhan Sathyaseelan 27:04
Right. But more on the mechanics side rather than machine elements. That makes sense.
Pius Wong 27:10
Yeah. But the weird issue is, depending on what job or research field you're going to do in bioengineering, you may have to learn a whole ton about gears. There's like, for example -- There's a field called microelectronic machines or MEMS. And a lot of bioengineers use them because they're sensors in your body, like an ingestible camera pill, for example. Maybe there's a mechanical system in there that, like, swivels a camera around inside the pill, so that when you swallow it, the camera is looking all around. And so there you would have to know about gears, but, you know, on a small scale or something. So, like, it just -- it totally is -- In my view, bioengineering is such -- it's too broad. It's so hard to study, because, like, you might have to be --
Pius Wong 27:10
The way I see it, it's like if looking at a Venn diagram, it's in an intersection of biology and mechanical.
Pius Wong 28:02
And electrical, and chemical.
Sadhan Sathyaseelan 28:06
Yeah. I get it.
Pius Wong 28:07
It's all that. But in any case, we'll save that for another discussion.
Sadhan Sathyaseelan 28:11
Yeah. So what else do you think is in mechanical engineering? So we looked at mechanics. We looked at -- I know this is like a long --
Pius Wong 28:18
This is why it takes forever to get an engineering degree. This is why it's great that you're listening to this podcast instead. So now you know if you listen to us -- they know -- people who listen know a little bit about dynamics or motion, statics, mechanics. They know about thermodynamics, heat and energy. They know that electronics is kind of involved and mechatronics.
Sadhan Sathyaseelan 28:38
Yeah, design is a big deal.
Pius Wong 28:40
Design. Design methodologies.
Sadhan Sathyaseelan 28:41
Oh, yeah I got one. Manufacturing and production.
Pius Wong 28:45
Sadhan Sathyaseelan 28:46
This is definitely something that we learn as mechanical engineers.
Pius Wong 28:50
Hey, so can I ask you a question before you get too detailed?
Sadhan Sathyaseelan 28:52
Pius Wong 28:52
I think that before I even studied this, I think there's a common maybe misconception, where people think design and manufacturing are maybe the same thing. What's the -- So help me state what the difference is between design versus manufacturing.
Sadhan Sathyaseelan 29:13
Okay, so design ends with you having a final sketch and a final drawing,
Pius Wong 29:20
Like a plan.
Sadhan Sathyaseelan 29:22
Yeah. That's it. Once you have that, manufacturing starts. So in terms of -- Okay, where the design end is: You have the dimensions -- Let's say you're designing --
Pius Wong 29:33
Sadhan Sathyaseelan 29:37
Okay, say you're designing a chair. Simple. So all you're doing is, you are thinking in terms of the dimensions, you're thinking in terms of the material, you're thinking in terms of: Okay, how much force is going to be on going to be placed on that?
Pius Wong 29:51
How heavy am I?
Sadhan Sathyaseelan 29:52
Yeah. Where do you need to put some reinforcements? So you think about those things, and then you have a design, and then you have -- There's so many softwares, which is again something I wanted to talk to you -- It's another part of our skills in terms of mechanical engineering. So you use all these softwares to, at the end, show that, hey, this is the shape, this is the material that I want this this part to be. And that's the end of design. That's where you draw the line. So everything that happens in order to make that into a live chair is manufacturing.
Pius Wong 30:29
Okay, then the person who's actually cutting the wood and putting in the screws or --
Sadhan Sathyaseelan 30:35
That process will be manufacturing.
Pius Wong 30:37
Sadhan Sathyaseelan 30:37
So once it once it goes in the physical side, actually building those things, it becomes manufacturing. So as when you're designing the chair, you are thinking about, hey, how's this going to be manufactured?
Pius Wong 30:49
Like I don't want to carve this chair out of a solid piece of wood, right?
Sadhan Sathyaseelan 30:53
Sat that again?
Pius Wong 30:54
Like I would not want to carve this chair that I've designed out of a solid block of wood.
Sadhan Sathyaseelan 30:58
You can design, but the manufacturer is going to hate you. [laughs] It's just going to be harder to make.
Pius Wong 31:03
Yes, manufacturers and engineering techs will hate the engineer, if the engineers have really poor --
Sadhan Sathyaseelan 31:09
Knowing how its manufactured.
Pius Wong 31:11
Sadhan Sathyaseelan 31:11
So you need to learn to -- I guess, as an engineer, you also need to learn, hey, what's the extent of our manufacturing capabilities? And also assembly capabilities? So all of these things are taken into account when you design.
Pius Wong 31:24
I think every engineer has to build the stuff that they create for the first couple of years so that they know how horrible they design things if they can't build it.
Sadhan Sathyaseelan 31:33
Yeah. If you're -- You know, I guess it goes in the realm of tinkering. And, you know, you tinker with stuff, and you see that, hey, this is the easy way to build. But essentially, you're learning all that through trial and error that past people have done, and they have specific sets of rules that you can learn, and then you can apply. So I guess that's a difference.
Pius Wong 31:54
Yeah. So there would probably be a whole class on manufacturing engineering, different ways to build things, and then how to design things so that you can even build them in the first place.
Sadhan Sathyaseelan 32:05
Pius Wong 32:06
Okay. And let's talk about software real quick because you mentioned --
Sadhan Sathyaseelan 32:10
Skills. I want to quickly mention a little bit about manufacturing, as well. What is dealt in manufacturing? It ranges in a big way. I think most of manufacturing is taught as electives. So, in terms of manufacturing, essentially, we learn at the very basic -- foundry, how to cast a piece of --
Pius Wong 32:36
Sadhan Sathyaseelan 32:36
It starts from there.
Pius Wong 32:37
I never did that.
Sadhan Sathyaseelan 32:38
I did it. It was awesome.
Pius Wong 32:40
You made your own metal -- Did you make your own, like, molds and everything?
Sadhan Sathyaseelan 32:44
We learned to -- We didn't actually go through the melting process or anything, but we just learned how to make a cast out of the sand. And then, the process continues, but we stopped there. But UT does it all the way through. They use aluminum. I saw a few students working on it the other day.
Pius Wong 33:02
Sadhan Sathyaseelan 33:03
So it's pretty cool. It starts from there, which is like foundry. Think about that. If you think about it, that's like 400, 500 years back, they were doing that.
Pius Wong 33:11
Yeah, making swords and stuff.
Sadhan Sathyaseelan 33:13
Yeah. Probably a lot older than that. Because I know in India people were using swords like 5000, 6000 years back. So yeah. So you start from there. You learn from those basics. And through electives you can to to learn the modern, the most modern. You were talking about 3D printing or nanomanufacturing.
Pius Wong 33:35
Yeah. Are there any other modern manufacturing methods -- I'm trying to think.
Sadhan Sathyaseelan 33:39
Hmm, I think 3D printing is the most --
Pius Wong 33:40
That's the one that's always in the news and --
Sadhan Sathyaseelan 33:43
That's where we hit a plateau right now. So that's what I wanted to add in terms of manufacturing and production. They're also like small things that you learn here and there, in terms of quality control --
Pius Wong 33:58
That goes to industrial engineering a bit.
Sadhan Sathyaseelan 34:00
Kind of. Yeah.
Pius Wong 34:01
Quality -- You're right. There's more statistics and stuff involved in that.
Sadhan Sathyaseelan 34:05
That's not as necessary in the realm of mechanical engineering, at the core of it, but maybe if we have time we can talk about it a little bit.
Pius Wong 34:13
Sadhan Sathyaseelan 34:14
Pius Wong 34:15
Yeah. What do you mean by skills as opposed to these other classes?
Sadhan Sathyaseelan 34:19
Yeah. So I think the way I want to differentiate that is -- So what we spoke about in terms of mechanics, in terms of thermodynamics, these are concepts that students need to learn, you know, over time. But in terms of certain skill sets that they can develop, one of the main skills is using computer software that will aid them in sketching things faster in a much more efficient way. So I guess we used to do -- or you know, we're talking about design -- Hey, how do you sketch these things? How do you -- If you're designing a chair, do you use your hands and draw on a piece of paper? That's what they used to do. Now they don't do it anymore, because it's just time-consuming. It's easy for errors to happen.
Pius Wong 35:07
Right, not in any official records. Like, it's not going to be some sketch on a napkin. Maybe, like, when you're creating ideas.
Sadhan Sathyaseelan 35:15
But if you're handing -- Once you're done with your design, if you're handing it over to manufacturing, there are certain rules you have to follow when you give them -- Yeah, so it used to be done with hand. t's called -- it was called drafting. And then right now it's mostly done in software like SolidWorks and CAD. And there are also software that will let you analyze those things, in terms of, if you want to -- on the on the software, you can heat up the chair and then see how much temperature it will take for it to, you know, catch fire.
Pius Wong 35:50
So you're simulating the thermodynamics, or you're simulating maybe the forces when you smack it with a hammer or something.
Sadhan Sathyaseelan 35:56
So all of those things can be done using software that's built by some companies. These are these are some of the things that students do learn during engineering, not essentially as a part of a curriculum, even though it might be introduced as part of a curriculum. But most often than not, they learn by themselves, outside of the classroom by doing that.
Pius Wong 36:18
Right, maybe in the company that they end up working for, they might train them how to use these tools. It's a tool, ultimately. It's like how to use a hammer.
Sadhan Sathyaseelan 36:27
Pius Wong 36:27
It's an important tool. I mean, I've seen --
Sadhan Sathyaseelan 36:29
It's vitally important. It's very. very, very, very important.
Pius Wong 36:34
Sadhan Sathyaseelan 36:35
And there are also software tools that can let you design pipeline systems, fluid mechanics, how much pressure should be there? Where should you put a wall? So there's a lot of software that you learn outside of this core content. So we will get to that.
Pius Wong 36:52
There's one final thing. I think we covered a lot of the core stuff, but there's one final category of topics that I want to briefly talk about. So whenever you go to school to try to get an engineering degree, especially in undergrad, there's a bunch of stuff you have to learn that's not in the mechanical engineering -- what's a word -- major. Like, you've got to learn some chemistry. If I look at the University of Texas's list of graduation requirements, you have to learn not only math, but you have to take, like, a social science class. You might have to take a humanities class. There might be an engineering finance class. There might be like a computer programming class, or an art class or something. That's a lot of classes. And so how much should we even talk about these other things that are not really traditionally part of mechanical engineering, whether it's engineering ethics, or finance, or art, or any of that stuff?
Sadhan Sathyaseelan 37:54
Art? I don't think we should, because -- My understanding is this. I didn't -- So there was one requirement for UT. It was -- they had to take some kind of a governance class, which was not a requirement for me when I was doing undergrad in India. So they don't overlap at all. So we can leave out the humanities in the arts part. We can we can talk about what they learn, and why it might be important. For example, governance is important if you're in Texas, so you know where oil fields are, what are the laws governing them. So for that, might be useful. But it's not a universal thing that you need to learn.
Pius Wong 38:35
I guess it's really specific to --
Sadhan Sathyaseelan 38:36
Pius Wong 38:37
Your job, yeah, lots of things.
Sadhan Sathyaseelan 38:40
Pius Wong 38:40
Maybe -- What I can see is, if we ever talk about any specific examples that are relevant to a particular field -- like thermodynamics, we might talk about, you know, the explosion of the shuttle Columbia or something. Then that might go into things like engineering ethics, or government.
Sadhan Sathyaseelan 38:58
Yeah, that's true.
Pius Wong 38:59
So I don't think we'll -- It sounds like we're not going to have any specific episode on those things. But I bet engineering finance and ethics, it'll come up. Okay.
Sadhan Sathyaseelan 39:10
The chemistry and physics and mathematics. So one thing we're consciously avoiding is talking about mathematics to explain engineering concepts. We're not going to do that. Unless they're like --
Pius Wong 39:24
But on an intuitive level --
Sadhan Sathyaseelan 39:26
On an intuitive level, yes.
Pius Wong 39:27
Like when things get bigger, something else gets smaller. The idea of more and less and like stuff like that.
Sadhan Sathyaseelan 39:33
Yeah, I'm saying like, let's not -- We're going to avoid talking about engineering with mathematical terminology. Yeah, we're not gonna do that. Even though we're not going to do that, but --
Pius Wong 39:45
I think it's great. Like, we're already talking for a long time without any math. If we started bringing in math, it would be that much more.
Sadhan Sathyaseelan 39:55
And also, it's like, math is a huge ocean by itself. It's not something -- Yeah, we're not going to do that. That's just -- It takes a different level of commitment to grasp those concepts before we can move on to --
Pius Wong 40:09
You can talk about engineering without talking about the detailed math.
Sadhan Sathyaseelan 40:14
Yeah, we can. We'll try to attempt that.
Pius Wong 40:17
Sadhan Sathyaseelan 40:18
As much as we can.
Pius Wong 40:19
People do it. So we're gonna talk about all of that, Sadhan.
Sadhan Sathyaseelan 40:23
Yup. I think we'll get it going.
Pius Wong 40:26
Sadhan Sathyaseelan 40:27
Pius Wong 40:28
Until we meet again.
Pius Wong 40:34
This has been Sadhan Sathyaseelan and Pius Wong, your engineers for today. If you like this episode, stay tuned for more episodes where we go a little bit more in depth on mechanical engineering.
Pius Wong 40:45
For transcripts, links and other notes related to today's episode, visit the podcast website, k12engineering.net. There you can also get links to our Facebook page, the Twitter profile, and more. Remember to subscribe to the show on iTunes, SoundCloud, or wherever you find your podcasts. And finally, thank you so much for the donors on Patreon who are supporting this show, and all my projects, in my independent studio Pios Labs. If you like this podcast or any of the other projects that I'm doing, please donate, too, at patreon.com/pioslabs.
Pius Wong 41:21
The opening music in today's episode is called "Soar," and our closing music is called "Polar". Both are by the artist Chrispop. You can find more music by Chrispop on Soundcloud under the username chrispop99. That's Chris with a C-H, or just check the show notes for a link to his music. Thanks to Chrispop for letting us use his music with permission. The K12 Engineering Education Podcast is a production of Pios Labs. Thanks so much for listening, and tune in next time.