Anatomy of a 3D Printer

For newcomers, it may be confusing to know all the parts of a 3D printer. This 3D printer anatomy overview should give you a good idea of what parts a traditional FDM printer will consist of.

1. X-axis - The left and right motions move along the X-axis.
1. X-axis motor
2. Y-axis - The forward and backward motions move along the Y-axis. The print bed usually will move along the Y-axis.
1. Y-axis motor
3. Z-axis - The up and down motions move along the Z-axis.
1. Z-axis motor - Behind frame
4. Print Bed - This is the surface where the print will be built on. The print bed surface that can be made of a variety of materials that help the print stick to the bed. PEI is a common material that can be added to the print bed and helps with adhesion. There are also more premium print surfaces such as FilaPrint by FilaFarm that benefits from easy remove of prints.
5. Controller - This is the brain of the printer. It is usually where interface for controlling the printer is and where all the other parts are plugged into. 3D printers have many kinds of firmware that can run on them. One of the most popular is Marlin.
6. Extruder - This is how the filament gets pushed into the nozzle for printing. There is a motor with a gear that turns and slowly pushes filament into the Hotend. There are many kinds of extruders that hold different properties such as the Flexion extruder that is specially designed for flexible filament. Extruders can come in 2 styles: bowden or direct drive.
1. Extruder Motor
7. Bowden tube - This is the tube that has filament running through it. This only applies to setups with a bowden style extruder.
8. Hotend - The hotend assembly is where the plastic melts so it can be deposited onto the print. The hotend is comprised of a few parts.
1. Nozzle - The nozzle gets hot and melts the filament. The nozzle is connected to the heater block. It comes in many sizes ranging from 0.1mm to as much as 2mm or beyond depending on the application. The typical size is 0.4mm. The nozzle can be swapped out for other sizes as needed.
2. Heater block - The heater block is where the heater cartridge is connected. There may or may not be insulation around the block. Insulation helps with preventing heat fluctuation.
3. Heater Cartridge - The heater cartridge runs through the heater block as the source of heat for the hotend.
4. Thermistor - The thermistor is positioned just inside the heater block and reads the temperature of the hotend.
5. Heat Break and Heat Sink- The heat break is the portion of the hotend that needs to be cooled in order to prevent the heat from the heater block from traveling too far up the hotend. Ideally the heat should be isolated to where the plastic is melting. Softening of the filament too far up the hotend will cause clogging.
6. Cooling fan - The cooling fan cools the heat break.
7. Part cooling fan - The part cooling fan quickly cools the material that has just been deposited. Not all printers have this and it is not always required. The requirement depends on the material being used. For example, PLA filament benefits greatly from being cooled quickly as opposed to ABS filament which may warp if cooled too quickly.
9. End stops/Limit switches - End stops mark the home position of each axis. When homing the printer (moving the axes to their home position), each axis will move towards these ends stops. Once it reaches the end stop, the movement of that axis will stop. This tells the printer that the axis has reached its home position.
10. Extras - these parts are not required but they are becoming more common place.
1. Auto level sensor - Auto level sensors are completely optional and they come in many different forms. Sometimes it will be used in place of an end stop for the Z axis. This sensor is used to measure where the low and high points are the on bed so that the printer can compensate for the differences. This allows the printer to print on the surface evenly even if the bed is uneven. This can eliminate the need to level the bed manually. An example of such device is the wildly popular BLTouch by ANTCLABS.
2. Filament sensor - This unit detects when the filament runs out and pauses the print.