We continue with the entries destined to know our FFF 3D printer within our section of design for 3D printing.
Now it’s time to go into detail on the elements that usually form domestic 3D printers, seeing the main components that we will find in the printers and their functionality.
Knowing these components will allow us to understand how our machine works, dare to make improvements or repairs, and even dare to design our own 3D printers!
So let’s see each of these components that make up (or can make up) our printer, organized by category and function.
We start with the most basic and perhaps most obvious. We have the elements that make up the structure. Here we will find folded sheets, structural profiles, brackets, and angles.
We can find both metallic and plastic/acrylic elements, but we will always prefer metallic elements in principle for being more robust.
Special mention deserves the generic type structural profiles, very useful especially if we are designing our own CNC machine.
Now that we have solved the movement with motors, pulleys, and threaded rods, we need to register or guide the elements, so that the positioning is smooth and precise.
A common option is to use smooth rods, on which the element we want to move will slide.
To allow the movement, we will find bushings, in which the rod is inserted, and while the body holds the element we want to guide.
Another option is to use guides and profiles. Its operation is similar to the rods.
Finally, although less frequent, we can also find bearings, as elements that favor rotation. For example, we can find them to hold one end of a threaded rod.
As we said, our 3D printer needs to move. The normal thing is to use Nema 17 type stepper motors, which are already old acquaintances of our blog.
We will need at least 4 motors, 3 for the movement of the 3 axes, and a fourth to introduce the filament. Although they may have more, if any axis has a double motor.
We will also find couplings, which serve to connect the motors with other elements. We can find fixed or flexible couplings.
On the other hand, our machine has to have linear displacements, while the motors produce rotary movements. Therefore, we need mechanisms to convert rotation into linear movement. There are two typical solutions.
The first of them is the threaded rod, a rod to which a helical groove is made (like a screw) and, when turning, it converts the movement into linear.
The other usual solution is pulleys. The bushing is attached to the motor and, when rotating, the pulley converts the rotational movement into linear movement.
Here we will group the elements that, in some way, intervene in the process of melting and depositing the filament.
So we start with the heated bed. As we have already mentioned on several occasions, it is the element on which the printing will be done. The bed is heated to improve the adhesion of the piece, without which it would be very difficult for the piece to be fixed.
On the other hand, we have the nozzle or hotend, which is the element responsible for melting and depositing the filament.
The hotend contains a thermoresistance that is responsible for raising the temperature to reach the melting point of the filament.
And a thermal sensor that is responsible for controlling the printing temperature.
On the other hand, we will have fans to cool both the hotend and the deposited filament. We will find both axial fans and turbo fans, the former used to cool the machine itself (the hotend) and the turbo fans to cool the material.
Finally, although it is not a thermal element (but if not, I didn’t know where to put it, it fits better here) we have bowden tubes and couplers, which are plastic tubes that guide the material inside the machine, usually between the extruder and the hotend.
As we saw in the previous post, in addition to the thermal and mechanical components, our printer has a series of electronic elements that control the entire process.
The first part and, surely the bulkiest, is the power supply, which converts the mains voltage to the voltages used by the printer’s electronics.
On the other hand, we will have a control board, which is the “brain” of our printer. There are many types of control boards, and it would be worth its own entry. But, in summary, its function is to control all the elements of the printer (motors, thermoresistance, thermal sensor, display, etc).
If you are curious, the Ramps is a very famous model and from which, in a way, many of the current boards inherit.
We will also have, normally mounted on the control board itself, the motor drivers. These are responsible for precisely controlling the movement of the stepper motors and are also old acquaintances of the blog.
So, in summary, these are the main types of components that we are going to find in our 3D printer.
We have already seen the basic aspects and components of a 3D printer, and their functionality. In the middle, it has been intuited that the extruder can be in the structure, or on the print head. We will see this in the next post where we will see Bowden type printers and direct type, and their advantages and disadvantages. Until next time!