How does 3D printing work?

talking about? Well, before we start talking, this is going to be one of those special podcasts, you know, the kind that always start with listener me. Dude, I was hoping I was ice cream and cake. You got me all excited. Yeah, No, punch and pie will be later. So this listener mail comes from Amy, and Amy says, hey, you guys love the show and I have learned a lot. Here is a tech thing I have no clue about. How does three D printing work? Thanks? Amy? Well, I

mean we thought we would tackle three D printing for you. Yeah, it's um, it's a complex thing. It's it's super cool though. Yeah, you can you know, you can do a very rudimentary version of this by you know, printing something out on a piece of paper. And folding it into oregamy. But I don't think, oh, that's printing on two D and then you make a three D dimensions that's it. Get josh in here. So no, no, no, So three D printing, Well, first of all, let's talk about why you would need

three D printing in the first place. And really, the main purpose is to create prototypes for products. Yeah, we're not we're not talking about printing out stuff that you would read later. This is printing out things in relief so that you could see how they're put together and what they look like when they're done. The question is how do you make that possible? Right, Because think about it this way. If you are let's let's say that you have come up with a product idea. You work

with this big company. You've come up with an idea of our new product, and you want to make a mock up of it. But because there it's it's the first of its type, there's nothing in place for you to be able to manufacture this easily. You can't just go to the plant and say, hey, you know, produce one of these for me, because no one's made one before.

So before three D printing, you pretty much had to use other methods, like if you want to go way back, we're talking about things like you take a block of wood and you carve it into the shape that it's supposed to be in, and then you're you take another block of wood and carve that away until you get all the different pieces together. Then you put all the pieces together, and then you show it off to whomever and say, this is what this is the way it's

supposed to go together. Please find a way to mass produce this. It's rather time consuming. It's carve away all the bits that don't look like whatever, right exactly, you carve away all the bits that don't look like whatever it is that you're trying to produce. Or another example is uh, actually group of uses three D printing a

lot architects. Everybody's seen name one of those models of your town or your school after renovation or whatever where they have little blocks and you look at them and you go, well, that's that's pretty neat to put all the little trees in there, and that well, you can use three D printing to create models like that, right,

So obviously there's a need for creating prototypes. There's need for creating these models and there's a need for doing it in a way that's not going to take you so much time that by the time you're done with it, the opportunity to create whatever was you're going to create in its past. So that's where we get in with this whole rapid prototype approach. And three D printing is really just a way of creating the various bits and pieces you need for some three D object three dimensional object.

Uh and uh you do it without having to you know, get other materials and carve it out yourself. Uh. And it's an additive process, which means that it's adding the material as it goes to build the ultimate object or series of objects. It's kind of ironic because really to print in three D, you're printing in two D just

lots and lots and lots of layers. Yeah, exactly. Yeah, it's kind of weird because you think of it in I guess in my head, I was thinking sort of a sci fi thing where you know, you had this big open door with the flaps on it, and you tell it to print the thing and it just sort of comes out in the conveyor belt. Well that's not exactly how kind of like the gob stoppers and will

want Yeah, no, I was right there with you. Either that or either that or you think of it almost like a mold type thing, where you know, these two halves come together. When they come apart, there's the object just sitting there. It's not quite like that. In fact, it's not like that at all. Really. One it really resembles most is in jet printers. So you know, with the name jet printer, you've got a printer that has a tiny little nozzle that sprays incredibly tiny drops of

ink onto the paper. Yes, an incredibly small we're talking like usually on the nano scale, really um something that or it can be that small and uh it just it the nozzle scans from one side of the paper to the other and sprays, and as it sprays, that's that's what's forming the text, you see. Well, it's the same sort of principle with three D printing, except instead of inc it's using some sort of material like a resin or some sort of uh plastic kind of material

and a binding agent. It depends actually I've seen a couple of different techniques, one that uses powder and another that uses a liquid. Right, Yeah, it all depends on there there are variations. In general, the way it works is that you first create a three D model of whatever it is you want to build in a program

like a like a CAD program on a computer. Um. Then what most of these three D printers do is they divide that picture that you've created, that model you've created, into lots and lots and lots of layers, hundreds and hundreds of them really, because the thickness of each layer tends to be very very thin. It's it's really just one layer of the of the ink jets printing. I

guess that's what you could call it. So interrupted ahead, think of it as an egg slicer, if you, like, you know, put the egg down and you slice it up. It only very very fine slices. It's the computer is doing that in order to print it on this three D printer, right the cross sections exactly. Yeah. So it does this layer by layer and it prints and until

it's finished with the object that you're creating. And because there's the binding agent or the material itself is binding in nature, um, it actually clings together and eventually creates this three dimensional object. You might think, well, how long does that take? Turns out not very long at all. Really, um, Even back in the early days of three D printing, it was much faster to use this method than other

comparable methods. Uh. And I've seen figures of depending on the complexity of the objects you're creating in the size of it tends to be between half an hour to two hours, depending on the again the size and complexity. M M. Do you want to talk about the different

types the powder and the liquid thing? Yeah, go ahead, okay, UM, Well, the one that I first saw when I was starting to do my research for the podcast was this stereolithographic technique, which is basically it's the liquid that they pour into a big I think of it as a big tub, I guess, although I guess it wouldn't have to necessarily be large, It just has to be big enough to contain the liquid. The laser is shown onto the resin, and every place that the laser touches hardens, so that's

how it forms the pattern. And then it that that becomes a layer and one of the layers that eventually makes up the three D So it starts as a liquid resin which is hardened by a laser into one of the layers that eventually becomes up at the model right right, So what you do is you you scan the laser across and it traces whatever the shape is of the that layer. Then usually there is a process

where I think of it like a squeegee. Uh, something comes across and wipes off the excess resin at that point so that the next layer can be built up. The laser goes across again, it binds with the first layer. You've now got a second layer. You do this hundreds and hundreds of times until you've finished the object that you're trying to create. Now, I should also point out that stereo lithography is not the same thing as the ink jet method we were talking about earlier. It's a

totally different kind of three D printing. Um. In fact, some people would argue that it shouldn't be called three D printing at all. It's still a form of rapid prototype. But but yes, it is a very popular way of creating a simple three D objects UM. And it is pretty neat. I mean, it's just it's a laser that once it comes into contact with the stuff, the stuff

goes from liquid to solids. That's just cool. But yeah, so so yes, that's the liquid one you were talking about, right, and then the the other uses a self adhesive powder and you know it's um. Actually I had less on So the powder, the powder. What happens is it gets it gets put into the same sort of pattern and it adheres to itself. It binds to itself. There's some methods here where you will actually have to have a base of some sort before you can start printing the shape.

So in other words, you can't just turn the printer on and tell it to go. You have to have some sort of foundation for the dust or liquid to adhere to um. So you might have a very basic cylinder, for example, and the object itself is as much more complex than that, with lots of curves or edges or whatever, but it still has to have that that foundation to cling onto before you can get started. That's some of

the printers require that. And uh, from what I understand that that term is selective laser centering or s l S, which is the name for that powder method. And then something else it's kind of interesting, at least to me, is that the three D models, when they have a continuous surface like this, they're called watertight. That's sort of I guess industry slang for you know the fact that it's seamless how the model is made, rather than being

made into pieces. So yeah, you're not gonna find you're not going to find that little line where two different pieces come together and are glued that way what you might have found with with old handmade versions where you had to put together a lot of different sections by yourself. And we're starting to see this more and more in applications beyond just the prototype production. Um it's not just

something that's being used by gigantic companies like you. You would see this normally in things like let's say you're at a car manufacturer and you've come up with a really cool design for a car, and you might want a model of that of your design when you're showing

that to executives. So you would use this method in order to create a model of the car design you had created, so they're not just looking at a you know, a three D image on a computer that can actually see an object and and look at it from all angles that way. Um. Well, now these three D printers have gone into the realm of affordability for a lot of smaller businesses. Now, when I say affordable. This is a relative term, right, It's not something that is affordable

to the general consumer. Uh. You know, Joe Schmo with his MacBook is not going to go out and get a three D printer to sit next to his computer at home. Uh, because Joe Schmo probably can't shell out grand for a three D printer, and that's for a cheap one. Yeah. The the average now is about somewhere between fifteen thousand and two d and fifty dollars for

a three D printer range. Although there are some desktop ish printers that are starting to come down below five thousand dollars, it's still not the kind of money that you're gonna, you know, fork over for your kids science fair projects so that you can the three cool three D printed thing. It's still a little You might be a you might be a model train enthusiast, but I doubt that you are an enthusiast at the point where you're gonna drop grand on a printer that can print

a tree that you want. Although I don't know, maybe you're Michael Jackson quality. He had a lot of model trains. That's true anyway. Yeah, you know they used these in a lot of different processes UM, some of which made complete sense to me, like manufacturing and aerospace and motive UM. One that I was a little surprised to see was footwear, but I guess people like to see what the shoe is gonna look like before the consumers get hold of it.

And uh in the arts uh. In fact, some of them models for Cora line were built uh for him. Nike founder Phil Knights company has uh. He had a company called Laka and uh. Apparently that company was involved with making some of the models for Coraline printed on you know, three D printing technology, and the medical industry is using them to print prosthetics, which is pretty cool.

And I remember reading at some point. I didn't find it for this podcast, but I do remember reading an article at one point about a former UM Microsoft executive, someone who worked on Microsoft's video game division actually who left the company and formed his own company UM that was the partnered with World of Warcraft so that players of World War Warcraft could send in pictures of their character the essentially their character model, and have a figuring

created through three D printing of their their character. So and it was using this method. It was using three D printing to create models that were very specific to the look of each individual World Warcraft character. So if you, you know, had one of those busty elf chicks, you could get a three D figuring of your bust yelf check. All right, Yeah, not life size. Sorry to disappoint you, fellas. Um it was actually like maybe three inches tall. But yeah,

you know, you can't have everything. If there were two apples taller than they'd be smurf size Smurf size two or three, And no, I think you're right at there's three three apples tall. So anyway, yes, that was a childhood well spent. So you know, uh, somebody there there is the three D printing, the rapid prototyping technology has fans. But you know, I was a little surprised to see somebody who who's very popular in the world of design

right now, who isn't necessarily a fan. Yeah, Jonathan, I've of apples saying that it's distancing designers from you know, the idea of their physical artwork of you know, actually doing it by hand. And so he, uh, he's apparently not such a big fan. I can sort of see that, I guess, I mean, I see that in the same way that I see some animators who specialize in hand drawn animation how they look down on computer generated animation. Uh,

not all of them do. I don't mean to say that, And it's a very small number who who have voiced any sort of negative opinion about the thing. But my view is that it's really it's not so much the technique, it's you know, how you how you put to use. So as far as I'm concerned, it's just another tool, and if someone is able to use that tool in a creative way, then I see no real problem with it. But then I'm not a designer, so I am not

an artiste. So perhaps that's uh, that's maybe it's because I'm more of a you know, practical kind of guy as opposed to a artistic kind of guy. I understand. But I was also going to talk a little bit about vic Oliver. I don't know, did you come across vic Oliver when you were researching three D printing? I did not. Okay, So vic Oliver he's heading this this open source self copying three D printer project self Copying. Yes.

So the idea here is that to create a three D printer that is capable of printing all of the components that go into that three D printer, so that in theory, you could create a machine that can replicate itself. Now, granted it's going to replicate itself in various bits and pieces. It'll still have to be assembled and wired and all that. But in theory, with the methods that he's working on, you would be able to create another printer, and that

would remove this barrier of price. Think about it, like, you know, you, let's say like for the purchase price of one printer and whatever materials you needed to feed it through, like the plastic in the metal that you would need to create more, you could then create another printer and give that to your friend, and then the two of you could each create a printer and give that to two other friends, and they could give it to two friends, and they two friends and so on

and so on. I'm really figured you were going to go to that. Uh you That's the problem with that is that there's no three D metal printing technology. Well, that's what that's what they're working on. They're working on this methodology that would allow you to use low metals that have a low melting point, so you would have a metal that could melt at a temperature that is lower than the temperature required for the plastic to stay hard. So you could actually line the plastic with metal and

it would all work fine. It wouldn't intermix, you wouldn't have this hot metal melting the plastic you just generated. And and granted now they're still working on it. They've developed the nozzle metal system, but it's still a little ways away from a full self replicable model. But I mean, that's that is a pretty neat thing, because you think about then, all right, well, how far away are we to the point where we get to the Star Trek world where you've got the replicators. I could use a

hot earl gray this afternoon. Yeah, I could have used a an alternator for my wife's car. So you know, we all have our our needs. But on the day that we recorded this, the waterman busted outside and there's a boil water order. And I really wanted a cup of tea, I think because I couldn't. Yeah, I had a cup of coffee before I found out about the boil water order. So I'm expecting to either die or develop superpowers before the end of this podcast. Sad thing

is he won't let me vote. No, No, it's pretty much a coin flip situation here. It's not a democracy. All right. Well, I'm pretty much done with a three D printing. What about you? I am too, and thanks to me for right now, because that's that was a lot of fun to research. It was a really cool topic and it was something I've been wondering about for ages.

In fact, as I a call that might have been one of the first articles I pitched at how Stuff Works when I started working here, although I never did get the chance to actually write that one. So it was cool to finally do the research so very much. So y'all continue to write in about stuff that we want to write about and read about. Right But this does, however, bring me to something else we need to talk about. But that would be listener me sabotage. Yeah yeah, listen

all y'all. So this listener mail comes from Jacob from Cleveland, and it's actually a dual listener mail because it's not just us, it's to our our bigger sister podcast stuff. You should know it as well. So I thought it was going to involve Aaron Burrn, No, not this time. You Now you may recall several episodes ago, I laid out a challenge to our listeners to create a spins arian sonnet in our honor, and more than a few responded, but Jacob's was the first. So here is Jacob's spins

Arian sonnet. Dear text stuff and stuff you should know of request for sonnets. Not everyone forgets to Chris, John, Josh or Chuck. These words should flow or anyone whom this poem gets. I love the podcast for their humor and wits, from bit Torrent to Einstein's brain, from listener mail and corrections someone admits to make me laugh. You all never refrain. In fact, you keep me from going insane. All fans of stuff podcasts, you guys should impress from

all your episodes. There is knowledge to gain. How much one can only guess a year of tech stuff, which I adore, and from stuff you should know just a little bit of time more ps tech stuff. I recommend a Linux podcast. Well, Jacob, we've got all the next podcast in the works for you. Uh, it's one of those many others. Yes, there's actually quite a quite a

long list of topics that that is accumulating. You guys are sending in requests faster than we can do podcasts, which is awesome because we don't have to think about them. But we've had a lot of requests for Linux, so that will be coming in the near future. So keep your ears peeled, I suppose or open yes, because you would keep your eyes peeled. I don't even want to

think about that. What peeling your eyes or your ears either? Okay, So if you have any requests or corrections or any other comments, you can send those to our email address, which is text stuff at how stuff works dot com. And remember you can read all about printers and computers and everything in between at how stuff works dot com and we will talk to you again unless Chris has something bad new pretty soon for moralness and thousands of

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