From a distance, the process of 3D printing looks like magic, but take a step closer and see how all the core systems and components work together to fabricate real physical objects from digital design files. In Module 2, we will look under the hood and learn about the core systems and components that make desktop 3D printing work, from interphase to motion mechanical system, from how an extruder works to the chemical properties of filament, feedstock, etc. We will tour through each element necessary for a clear understanding of desktop 3D printer hardware. Anatomy of a desktop 3D printer. When you hear the term anatomy, do you think dissecting frogs in a high school biology class? Or perhaps, you were thinking of human anatomy guides to where the organs are located. The systems that connect them and the circulation of fluids. You can trace a map of the signals that pass along the nerves from the tips of your fingers up through your arms and shoulders traveling up to the brainstem and into your brain. That is what we are going to be doing here, but with a robot instead of a frog or human, far less messy. The official definition of anatomy is the branch of the natural sciences focused on the structure and parts of living organisms. In this course, we will use the tools of anatomy to explore the structure, function and interrelation of the systems and components of 3D printer hardware, software and materials. While you probably have used any number of mechanical devices without thinking much about the various systems and components that make them work, here are three scenarios where knowing how your desktop 3D printer works under the hood can be a real advantage to you. Preparing your job files, performing basic maintenance repairs and calibration, and pushing your machine to the limits. Our incredible journey together this week explores the components and systems that make up a desktop 3D printer. To keep the scope narrow enough for a single week, I will be focusing on FFF extrusion printers here, with links to resources for desktop SLA and SLS printer anatomy in the notes. The sequence of subsystems. While there are a number of ways you can divide up a 3D printer into systems, I have opted to divide anatomy into these three simple groups; One, control system, two, mechanical system, and three, extrusion system. In the Fourth Module, I will also do an anatomy of what I consider a software system. We will look a bit at the physical layout of code and file formats, but since that topic isn't exploring physical hardware, let's put it aside for the moment. All the critical physical elements where software interacts with the machine itself are already incorporated into these three systems. Let's start with the control system. The control system covers everything involving electronics, power, and signal processing within the machine, including these subsystems and components; interface control board, firmware, power routing, signal routing, and network management. Now, let's look at the mechanical system. A mechanical system groups everything to do not only with motion but the chassis on which everything is mounted and when applicable the enclosure that shields the machine from the surrounding environment. The primary subsystems and components we will explore here are the motion mechanical subsystem, the build envelope, the frame, case, and enclosure. Finally, we will talk about the extrusion system. The extrusion system starts with the insertion of the filament and follows all the way through to molten plastic reaching the build platform. The extrusion system includes a number of subsystems and components that we will look at individually; material, feeder, hotend, active cooling, and build platform. Getting the print started. Here's the most important thing to remember. The role of each component and subsystem can fairly easily be sorted into control, extrusion, and mechanical system roles with a few overlaps. However, when you use a 3D printer, all three systems operate simultaneously and in tandem with each other. In fact, none of the systems can accomplish any of their goals without the assistance of the other systems. For example, the control system might happily issue instructions into the void without the mechanical and extrusion system. However, it will expect and require sensor data back from the elements hosted and activated by the other systems to confirm advance those instructions. So our story of the 3D printing anatomy must begin with acknowledging the need for these three systems to inter-operate, and this arrangement cuts both ways. These systems cannot operate in isolation nor are these three systems so completely integrated into each other that an error in one of these three aspects of the machine will be immediately recognized and responded to by the other. Though, thanks to Clever Firmware Design identifying a type of error from unusual sensor data reports can grant you a bit more visibility of one system into another. For these three systems to inter-operate successfully, they require the correct initial conditions be met. That's your job. It is up to you to deliver an accurate and reasonable job file to load and configure the correct printing materials, nozzle, build plate and better adhesion strategy and when you do your job well, observers' experience illusion of the machine as a single, seamlessly integrated system. The easiest way to tell this story and start off both the print and your journey through the 3D printer anatomy successfully is to step through the preliminary actions leading up to the moment that you hit "Print" to start fabricating your object, actions that will jump around among each of the three systems.
