Anatomy of a 3D Printer

Want to know what’s going on in that 3D printer of yours? Here we dissect a Fusion3 F306 printer to give you an overview of the main parts found inside most 3D printers. We don’t cover every single nut and bolt, just the important parts that are instrumental in printing. Click here for a printable version.

A. Cooling Fan

This blows cool air over the extruded plastic to cure the print and help it retain its shape. Some materials and prints may not need to have the cooling fan running while printing.

B. Heat Sink Fan

This fan blows air across the heat sink to prevent heat from creeping up the extruder barrel. Heat creep can cause some filaments to swell and jam in the extruder barrel.

C. User Interface

Most printers have an LCD display that alerts users of printer temperatures or other print-related data. This interface can provide simple data or can take the place of needing to have your printer connected to a computer for printing.

D. SD Card Slot

Many printers are equipped with an SD card slot that allows files to be directly loaded into the printer without the need to be connected to a computer.

E.Belts/Cables

Belts or cables are driven by motors to provide movement along the x and y axis.

F. Stepper Motors

This is a brushless, sychronous, DC motor found in everything from RC cars to electric automobiles. They provide precise movement from sprockets and belts to move the extruder, print bed and other parts on the printer.


M. Hot End

1. Heat Sink
The heat sink keeps heat from traveling upward and melting the plastic prematurely.
2. Heat Sink Fan
Attached to the heat sink, the fan blows air across the heat
sink to prevent heat from creeping upward in the filament.
3. PTFE Tube
The PTFE tube prevents heat from traveling up the extruder and melting filament prematurely.
4. Heater Cartridge/Heat Element
This heats up the plastic for extrusion. The heater cartridge is essentially a resistor.
5. Thermistor/Thermocouple/RTD
A thermisitor is the most common temperature sensor. It measures the temperature in the printer’s hot end. A thermocoupler works similarly, but can handle higher temperatures. These are usually ceramic or a polymer. A resistance temperature detector (RTD) also measures temperature in the hot end, but is metal.
6. Nozzle
This is the hold for the melted filament to be extruded. Nozzles come in different sizes and materials to accommodate the different filaments available


G. Hobbed Gear/Filament Drive Gear

The hobbed gear (sometimes referred to as the filament drive gear) is the gear that moves the filament to the extruder.

H. Print Bed

This is where objects are printed. Heated beds are best to prevent warping when printing with ABS. Non-heated beds work best with PLA (which isn’t as susceptible to warping). Check out our guide for bed prep recommendations.

I. Filament

Filament is a strand of plastic polymer that is extruded by the printer. Filament typically comes in 1.75mm or 2.85mm diameters. MakeShaper offers a wide range of filaments.

J. Leadscrews

Leadscrews typically drive movement to the z axis by rotating back and forth. They are similar in fashion to threaded rods, but leadscrews are purpose-built to provide more accuracy with less chance of backlash or wobble.

K. Power Supply

The power supply is an internal component that supplies power to the components within the printer. It works just like it does in any other electronic device, by converting AC (alternating current) from the outlet into steady, low voltage DC (direct current).

L. Motherboard

This is the brains of the printer! It contains the microprocessor and other circuitry that interacts with the other electrical components within the printer to orchestrate functions and interpret data.