Okay, we have talked generally about the background of desktop 3D printing and the technologies you are likely to encounter locally. Now let's go meet one of the desktop 3D printers that we will be exploring in detail during this course. We are here at the Ultimaker offices in Brooklyn, New York, within New Lab. When we set up offices here, we donated a number of our Ultimaker 2+ and 3 printers for other members of the space to use in 3D printer labs, offices, and desktops across the building. Given that these are the machines I have easiest access to for this course, I'll be using these as my point of reference when addressing features you can also find across the range of excellent desktop fused filament fabrication machines available in the marketplace today. Let's go say hello to an Ultimaker. We are here in a member desktop 3D printer lab at New Lab. And here's one of the Ultimaker 2+ printers happily working away. Let's take a look and see what's going on here. The thing you notice first is the toolhead moving around above the build platform. But if you took a snapshot of what's happening here, you'd probably miss the whole story. So what is happening here? What elements of the machine are critical to its mission? And how do you get what you'd want out of a machine like this? Well, Story actually begins back here, behind the machine, with the filament spool. This answers one of the first questions many visitors ask when they see a desktop 3D printer for the first time. Where does the ink, the plastic, the material that the part is created from come from? Well, here it is, it's this material, and it's being pulled into the machine very slowly by this filament drive mechanism here on the back of the machine. It goes up through this Bowden tube, which is attached on both sides. And that force that pushes from the back of the machine is translated into a pushing and pulling force down into the hot end. Most of what is happening in the hot end happens out of sight. The filament passes through the cold zone and into the transition zone, and down into the melt zone. By working out the math ahead of time, during the slicing operations, the goal of the printer is to balance the downward force of the cooled material that pistons down into the thermal chamber, with the transition of that filament at the front of this process, from the firm plastic into the hot gooey plastic. While it is hard to tell without getting really close, the toolhead is laying down a very fine thread of plastic, down everywhere on this layer of the part where it is needed. One way to think of this is that the machine is drawing the object one layer at a time, by drawing first the outline of the layer, the shells. And then filling in the main mass of the part with a sparse or solid infill pattern. You can see here that right now it is filling in the interior of the object with a sparse infill pattern, calculated to fill the object with a specific percentage of material compared to the volume, such as 5% or 20%. This saves material where you don't need much plastic, and speeds up the process of producing the item. Let's watch what the machine is doing for each layer. There are a range of excellent professional desktop 3D printers you might purchase or access today. And a range of approaches to each aspect of machine design, from mechanical motion to electronics to extruders, and beyond. I make an effort to mention other common types in these video lectures. And I will provide further details about other styles you might find interesting, including delta and polar style machines, in the resources for this course.
