3D 打印已成为一种更为主流的技术，几乎每个价位都有打印机可用。大多数想要 3D 打印机的人可能都能找到他们买得起的模型。尽管如此，3D 打印仍然很新，很少有人知道它是如何工作的。
这就是为什么现在是回答“ 3D 打印如何(How)工作？”这个问题的好时机。很有可能您最终将不得不使用一个！
增材与减材 3D 打印(Additive vs Subtractive 3D Printing)
3D打印有两大类。自己能买到的3D打印机几乎都是“增材”机器。换句话说，他们通过添加材料（通常在层中）来构建 3D 对象，直到对象完成。人们听到“3D 打印机”时想到的 3D 打印机几乎都是增材制造。
减法 3D 打印非常不同。在这里，您从固定数量的材料开始，然后移除材料，直到只剩下完成的对象。一位用大理石制作雕像的雕塑家正在使用减法方法。减法机器通常出现在大型车间和工业环境中。CNC铣削（计算机数控）系统可能是最著名的例子。
从现在开始，我们将只专注于增材机，因为它们与普通消费者相关。只需知道减材机与您可能放在桌子上的打印机属于同一个 3D 打印机系列。
熔融沉积建模、立体光刻和选择性激光烧结(Fused Deposition Modelling, Stereolithography and Selective Laser Sintering)
增材 3D 打印的三种主要方法是FDM（熔融沉积建模）、立体光刻（SLA）和选择性激光烧结（SLS）。
FDM是最常见的消费级系统。对于这些类型的打印机，材料的细丝通过热打印头。打印头精确定位在 3D 空间中，并根据精确的编程指令沉积一层材料。FDM有不同的方法，但我们稍后会介绍。
立体光刻(Stereolithography)在消费系统中不太常见。这些打印机使用激光将液态树脂固化成固态塑料材料。通常，物体是从一桶树脂中“拉”出来的，当它从材料中升起时，一层一层地形成。近年来，SLA 打印机变得更加紧凑和实惠。因此，它是FDM打印机的真正替代品，具体取决于您选择的最终型号。
选择性(Selective)激光烧结 ( SLS ) 使用强大的激光熔化聚合物粉末。实际的粉末充当打印的支撑结构，因此这种类型的打印不需要特殊的脚手架。SLS不是您可以在桌面上找到的一种FDM 。它现在仍然是一项工业技术。
笛卡尔和三角洲机器人打印机(Cartesian & Delta Robot Printers)
最常见的FDM打印机类型是笛卡尔 3D 打印机。该名称指的是笛卡尔坐标。那是我们在学校都学过的XYZ坐标。(XYZ)打印头可以移动到打印体积空间内的任何XYZ坐标。(XYZ)数学很简单，打印机价格实惠，打印质量精确。
但是，根据 XYZ 坐标的粒度，曲面可能不会尽可能平滑，需要进行一些手动修整工作。
Delta机器人打印机采用了不同的方法。打印头安装在三个臂上，三个臂在三个导轨上运行。通过改变每个臂的高度，打印头可以摆动。这种设计允许打印头以真实曲线摆动，还允许在打印体积内打印高大的物体。
基本上，导轨越长，模型就可以越高。Delta 机器人打印机不是使用 XYZ 坐标，而是使用三角函数来计算打印头位置。最终结果是它们无法达到与笛卡尔打印机完全相同的打印分辨率。
要真正理解 delta 机器人的概念，您需要亲眼看到它的实际应用。看看Johann Rocholl的这个视频，你很快就会明白这个概念。
注意(Notice)手臂上的关节以及打印头移动的自由度和平滑度。
3D 打印机材料(3D Printer Materials)
3D 打印机使用多种材料，但目前消费级应用中最常见的塑料有两种：ABS和PLA。
ABS（丙烯腈丁二烯苯乙烯）与制作(Acrylonitrile Butadiene Styrene)乐高(LEGO)积木的塑料完全相同。这种塑料在冷却时容易翘曲，需要带有加热打印床的打印机。它非常耐冲击，但不是特别强。它适用于制作原型零件，甚至是非承重的最终零件。
PLA（聚乳酸(Polylactic Acid)）具有低熔点、不易翘曲、易于使用且打印失败的情况较少。对于任何实际用途来说，它也太脆弱了，但它非常适合创建仅用于查看的平滑、详细的模型。
好消息是大多数消费级 3D 打印机都可以使用这两种廉价材料。因此，您可以根据需要更改它们。
尼龙(Nylon)丝是另一种选择，甚至还有使用木材或金属作为材料的打印机。下一代打印机一次还可以处理多个灯丝，允许混合材料或多色打印。
典型的 3D 打印过程(The Typical 3D Printing Process)
如果您从未自己制作过 3D 打印，您可能会好奇从用户的角度来看它实际上是如何工作的。虽然使用 3D 打印机并不像在激光或喷墨打印机上打印 2D 打印件那么容易，但它并不像您想象的那么困难。
根据手册设置打印机，正确校准和调平后，您首先需要一个模型来打印。
您可以使用Zbrush 或 AutoCAD( Zbrush or AutoCAD)等工具制作自己的模型，但大多数人可能会从在线站点下载模型。第一站绝对应该是Thingiverse，这很可能是最著名的用户提交模型集合。但是，有很多选择(alternatives)。
获得兼容格式的模型后，您将在打印机随附的软件中将其打开。它们的外观和工作方式都不同，但基本概念是相同的。您可能还想首先使用Meshmixer处理 3D 模型，以确保 3D 模型是实体的并且适合打印。
在 3D 打印机软件中，您将选择模型的大小和质量，软件会将其转换为代表每个打印层的“切片”。它还将计算在制造模型时必须打印以支撑模型的“脚手架”。打印完成后可以将这些东西折断。
完成所有准备工作后，就可以开始打印了。根据质量设置，您可能需要等待很长时间！高质量的印刷品从几个小时到几天不等。值得庆幸(Thankfully)的是，一些 3D 打印机可让您通过应用程序远程监控打印进度。
打印完成后，您将从床上取下它，然后将其从脚手架上取下。在许多情况下，您必须使用砂纸和特殊的切割工具来完成模型以去除瑕疵。有些人甚至画他们的模型！唯一真正的限制是你的创造力。
如果您渴望购买 3D 打印机，这些是我们的最佳选择(best picks)，如果您有预算，这些是更适合口袋的选择。
HDG Explains : How Does 3D Printing Work?
3D printіng has become a much more mainstream technology, with printing machines availаble at just about every price point. Most реoplе who want a 3D printer cаn probably find a model thеy can afford. Dеspite this, 3D printing is still so new that few people know how it works.
This is why now is a good time to answer the question “How does 3D printing work?”. There’s a very good chance you’ll have to use one eventually!
Additive vs Subtractive 3D Printing
There are two broad categories of 3D printing. The 3D printers that you can buy yourself are almost all “additive” machines. In other words, they build 3D objects by adding material (usually in layers) until the object is complete. The 3D printers people think of when they hear “3D printer” is almost always of the additive variety.
Subtractive 3D printing is very different. Here you start with a fixed amount of material and then remove material until only the finished object is left. A sculptor making a statue out of marble is using a subtractive method. Subtractive machines are usually found in large workshops and industrial settings. CNC milling (computer numerical control) systems are probably the best-known example.
We’ll only be concentrating on additive machines from here on out, since they’re relevant to the average consumer. Just know that subtractive machines belong to the same extended family of 3D printers as the one you might put on a desk.
Fused Deposition Modelling, Stereolithography and Selective Laser Sintering
The three main methods of additive 3D printing are FDM (fused deposition modelling), stereolithography (SLA) and selective laser sintering (SLS).
FDM is the most common consumer-grade system. With these types of printers a filament of material is passed through a hot print head. The print head is precisely positioned in 3D-space and deposits a layer of material according to exact programmed instructions. There are different approaches to FDM, but we’ll get to that in a moment.
Stereolithography is much less common in consumer systems. These printers use lasers to cure a liquid resin into a solid plastic material. Usually, the object is “pulled” from a vat of resin, forming layer by layer as it rises from the material. In recent years SLA printers have become more compact and affordable. So it’s a real alternative to FDM printers, depending on what type of final model you settle on.
Selective laser sintering (SLS) uses a powerful laser to fuse a polymer powder. The actual powder acts as a support structure for the print, so this type of printing doesn’t need special scaffolding. SLS is not a type of FDM you’ll find on the desktop. It’s still an industrial technology for now.
Cartesian & Delta Robot Printers
The most common type of FDM printer is the cartesian 3D printer. The name refers to cartesian coordinates. That’s the XYZ coordinates we all learned in school. The print head can be moved to any XYZ coordinate within the print volume space. The math is simple, the printers are pretty affordable and print quality is precise.
However, depending on how granular the XYZ coordinates are, curved surfaces might not be as smooth as they could be, requiring some manual finishing work.
Delta robot printers take a different approach. The print head is mounted to three arms that run on three rails. By varying the height of each arm, the print head can swing. This design allows for the print head to swing in true curves and also allows for tall objects to be printed within the print volume.
Basically, the longer the rails are, the taller the model can be. Rather than XYZ coordinates, delta robot printers use trigonometry to calculate print head position. The end result is that they can’t reach quite the same print resolution as cartesian printers.
To really understand the delta robot concept, you need to see it in action. Have a look at this video by Johann Rocholl and you’ll quickly get the concept.
Notice the articulation on the arms and how freely and smoothly the print head can move.
3D Printer Materials
3D printers use a variety of materials, but there are two plastics that are by far the most common in consumer-grade applications: ABS and PLA.
ABS (Acrylonitrile Butadiene Styrene) is exactly the same plastic that LEGO bricks are made of. This plastic is susceptible to warping when cooling down and needs a printer with a heated print bed. It’s quite impact resistant, but not particularly strong. It’s suitable for making prototype parts and even final parts that aren’t load-bearing.
PLA (Polylactic Acid) has a low melting point, doesn’t warp much, is easy to work with and has fewer failed prints. It’s also far too brittle for any practical use, but it is brilliant for creating smooth, detailed models that are only meant to be looked at.
The good news is that most consumer 3D printers will work with both of these inexpensive materials. So you can change them out as your needs require.
Nylon filament is another option and there are even printers that use wood or metal as a material. Next-generation printers can also handle more than one filament at a time, allowing for mixed material or multi-color prints.
The Typical 3D Printing Process
If you’ve never made a 3D print yourself, you’re probably curious about how it actually works from a user perspective. While using a 3D printer isn’t as easy as knocking out 2D prints on a laser or inkjet printer, it’s not nearly as difficult as you might think.
After setting up the printer according to the manual, with calibration and levelling done correctly, you first need a model to print.
You can make your own model, using something like Zbrush or AutoCAD, but most people are likely to download a model from an online site. The first stop should definitely be Thingiverse, which is quite possibly the most famous collection of user-submitted models. However, there are many alternatives.
After getting a model in a compatible format, you’ll open it up in the software that came with your printer. They all look and work differently, but the basic concept is the same. You may also want to first treat a 3D model with Meshmixer, which ensures that a 3D model is solid and suitable for printing.
In the 3D printer software, you’ll pick the size and quality of the model and the software will convert it into “slices” representing each print layer. It will also calculate the “scaffolding” that has to be printed to support the model while it’s being made. This stuff can be broken off when the print is done.
With all that prep work behind you, the print can begin. Depending on the quality settings, you might be in for a long wait! High quality prints vary from a few hours to a few days. Thankfully, some 3D printers let you monitor the progress of your print remotely via an app.
Once the print is done, you’ll remove it from the bed and then break it free of the scaffolding. In many cases you’ll have to finish the model using sandpaper and special cutting tools to remove imperfections. Some people even paint their models! The only real limit is your creativity.
If you’re itching to buy a 3D printer, these are our best picks and if you’re on a budget, these are more pocket friendly options.
