Author: Ansen Yao
Link:/question/20382142/answer/84028929
Source: Zhihu
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In fact, 3d printers, although there are many and varied brands, but essentially the same principle of work, so in the end what is a principle of work.
Since it is printing, then we will first look at the traditional, inkjet printer printing on paper.
Figure ? Paper printer, is not difficult to see, all right this is to let you feel just a little, later there X figure.
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We all know that paper printers print flat images, and the digital image is that we zoomed in to see a pure color "pixel" point collocation of things, this thing can be seen as a coordinate point marked with a color value of each as a storage.
Figure Pixel ? Scroll down quickly if you're dense-phobic
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So it makes sense that if we could create a "printhead" that could move freely in a plane and spray pixels in that coordinate system, we'd be done with printing.
Figure ? Planar Cartesian Coordinate System
So this kind of thing came about, and I modeled it with some simplification for the sake of understanding.
Figure ? How an inkjet printer works in the most straightforward way
The first thing we need is this printhead, which needs to spray "pixels" one by one, OK, let's see what's going on with the printhead in general.
Figure ? The printhead of an inkjet printer
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The paper can be brought down by a roller, that is to say, to complete the movement of the Y-axis, and the little nimble nozzle in the center moves from side to side, that is to say, to complete the movement of the X-axis, and then in this way, a flat picture will be printed out.
But the little nozzle in the center moves by what.
Figure ? Synchronous belt (toothed belt)
Yes, this is the scientific name for the synchronous belt we generally call the toothed belt thing, this thing, once with the gears, can be done to drive freely, that is to say, in general, very sensitive devices like printers, generally need to have a toothed belt as a transmission device.
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Some people say you say so much nonsense why, I want to hear is 3d printing. Rest assured, let's look at, flat printing carrier is paper, then we have to print three-dimensional things ah, flat printing is sprayed "paint", then 3d printing must be used in the real material ah.
Okay, here comes the magic bullet.
Figure ? General 3d printing commonly used "line material"
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That is to say, our common 3d printer, print the material from the ink to "thermoplastic", what is called thermoplastic it, this plastic once heated, it becomes soft and collapses. This kind of plastic once heated becomes soft and collapses in a molten state, but once cooled down and back to its original state. Now the most common 3d printing materials are mainly ABS and PLA, ABS is an extremely common synthetic plastics, the essence of A (acrylene eye), B (butadiene), S (styrene), forget forget good. PLA is also known as polylactic acid, the melting point of this thing is very low, basically in the 185 ° C can be melted processing, so that is the most common printing materials, as to why this material is and woolen thread As for why this material is the same as wool, it's actually quite simple. If you put a handful of plastic (granules) in a hot nozzle, it will be blocked in less than two minutes, and this wire is the only thing that's "thin and long-lasting".
Well, the material is there, just need a carrier, then yes, let's add a small steel plate.
Figure I added a small steel plate directly to the picture above when I was modeling, but of course the plate can't be fed by the rollers like paper can, so we added a "timing belt" underneath the plate for the Y-axis drive.
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Now that the platform is set up, the X-axis and Y-axis are free to move, and the small nozzle is free to reach any position of the small steel plate.
Then the printing of three-dimensional elements are missing one, right, and that is the Z-axis.
Photo: Spatial Cartesian Coordinate System
Photo: Here comes the Z-axis, the spiral bar shown above
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We added a mechanical "magic bullet" to the printhead assembly that can move back and forth in the X-axis, which is the "screw". "screw".
Screw this thing, we can also understand is a big screw, and screw with the place is a nut, the screw once the motor driven rotation, then the nozzle will be free to move up and down.
Well, our nozzle is not an ordinary nozzle, it is a nozzle that can move freely in the space.
Let's take a look at the result.
Photo The device we just assembled (I rendered a splash of orange and yellow for aesthetics).
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This is actually the basic drive construction of a 3d printer, it's not very complicated, it's essentially just a printhead that can move freely in three axes.
Well, now let's load up the bullets (raw materials) and see how this thing works.
Figure ? A loaded 3d printer
We find that 3d printing is essentially melting thermoplastic, then spraying finer "filaments" out of the nozzle, then spraying them upward, layer by layer, stacking them on top of each other. In essence, 3d printing is simply combining layers and layers of "flat surfaces" to make them three-dimensional.
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Figure ? The principle of 3d printing was mimicked with software
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Figure ? Here are a couple of objects printed on a low-precision 3d printer, you can clearly see the layered overlays and strands of support lines, but in many cases this precision is more than enough.
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We all know that if you print a flat image, usually get a JPG image is good, so in 3d printing, we usually use what "file" to print it.
Figure ? In fact, the printer with the metallic light you just saw was rendered from this.
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This is an industrial design and construction are very commonly used software - rhino (rhino), of course, more commonly used as well as solidworks this kind of parts manufacturing and assembly for the specialty of the modeling software. These two are relatively engineering modeling software, if it is more artistic a little bit more familiar 3dmax and Maya modeling software, although these software modeling principles are not exactly the same, but the core is nothing more than the surface into the body, all the "body" in the world, essentially are from the surface to All the "bodies" in the world are essentially made up of surfaces, so the modeling software works in the same way. Almost all of the world's modeling software has a basic command, which is - extrusion.
Figure ? The extrusion process created by stretching a face in the Y-axis
Figure ? A more complex assembly part for solidworks
Figure ? The Monkey Mace I made, which I do want to print out sometime
Including this Monkey Mace, which actually looked like this before it was rendered.
Photo ? Monkey Sai Lei without rendering
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So to complete an almost 3d print, first of all still need to solve the modeling of this level, but because I'm not an art class, the modeling ability is still not comparable to some of the animation god, can only say that the modeling some of the industrial parts and the shell of the product can be okay.
Then either rhino 3dm format, or 3dmax max format, or directX mode, etc., we can use their respective software will be saved as STL mode, that is, applicable to the mode of 3D printing.
Figure ?STL, a common format for 3d printing
Okay, so the next step is to import the STL file into the driver software, and we can start printing.
Figure PLA printing driver software for low precision 3d printing, we can see the various parameters on the top when printing, and of course there is what I talked about at the beginning, we can use the disk on the top to debug the movement of the X, Y, Z axes, and control the temperature with the buttons on the bottom, I can only take a picture of a Japanese one because I'm in an island country.
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Figure ? Printing begins
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This is actually what it looks like at the end already, we can use this physical picture to see the inside of the 3d printer, it's actually pretty much the same as the one I modeled at the beginning, but it probably looks like it's messed up with a few more lines.
Well, the above is the most basic of how a low precision 3d printer works and the workflow.
But don't worry, it's not over yet, let's take a look at the other modes of high precision 3d printers in this world.
As we know, now the plane printer, in addition to inkjet, there are laser printers, electrostatic printers, etc., then the 3d printer is the same, but do not look at the name of the fancy, in fact, the essence of the principle of work is still the same as what I just said.
We'll start with the flat printers.
For example, a flat laser printer is essentially a beam of light "image" through the "toner cartridge" into an electrostatic "image", and then a piece of toner selective "curing". "cured" and then transferred to paper.
Figure Flatbed laser printer working principle
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In fact, do not mull over this can also be, to put it simply, is a free movement of the printhead inkjet curing, a laser electrostatic in a large sea of toner selective curing.
So in fact, in addition to the above, layering thermoplastic 3d printer, there is also a and flat laser printer principle is very similar to the high-precision 3d printer.
We also have a name for this kind of printer, called SLA.
We know that the thermoplastic we talked about on the wall actually has a little friend, called "thermosetting plastics", that is to say, this kind of plastic in the usual state is likely to be a liquid, and once after the high temperature or bright light or catalyst, it will be the same as pointing tofu. The plastic will solidify like tofu, and it cannot be thermoplasticized again, meaning it can only hold a shape for the rest of its life.
The SLA3d printer
We can see that the printer is a "sea" of thermoset plastics that are selectively solidified by a laser beam for more accurate printing, but it still essentially works by forming a flat surface in X and Y, and then printing one layer at a time in the Z-axis.
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Of course, there are also SLS (Selective Laser Sintering) 3d printers that work in a very similar way to this type of printer, which is also known as selective laser sintering.
Figure Selective Laser Sintering Technology
This is a very high precision 3d printing, only to replace the liquid above with powder material, through the laser on the ocean of powder selective fusion, in fact, a little similar to the plane of the laser printer, but the essence of the 3d modeling is still the mode described above. sls printing mode can be applied to the metal 3d printing, sort of 3d printing, the printing of the metal, the printing of the metal, the printing of the metal, the printing of the metal, the printing of the metal, the printing of the metal, the printing of the metal, the printing of the metal, the printing of the metal. printing, which is a great step forward in 3d printing.
Figure ? A metal pistol printed using selective laser sintering
Well, let's show you what we can do with the high-precision 3d printer mentioned above.
Figure ? AGILISTA from my lab on the island, kind of a very good high precision 3d printer in Japan.
Figure ? The internal structure of this printer, you can see that all kinds of transmission devices are much more precise
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Figure The solidworks parts printed with high-precision 3d printer, this material printed by the spring also has elasticity, and this kind of precision can also cope with some medical equipment.
Figure high-precision model
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Well, that's all, it's already 5 o'clock, I've answered more humanities questions on Zhihu to get a lot of support from you, and I'd like to popularize the knowledge in this area more than I have in my own profession.
In fact, for 3d printing, there is a saying - the conception of the 19th century, the basic technology of the 20th century, the market of the 21st century.
It can be said that in the gradual progress of industrial design and modeling software renovation today, 3d printing for mass production of complex shapes and personalized customization as well as polymer materials processing has an immeasurable space, the 21st century 3d printing will still be the rapid development of the designers and manufacturers in the generation of efforts, I believe that the 3d printing can really, completely change the world.