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What Does The Extruder Do In A 3D Printer

What Does The Extruder Do In A 3D Printer | 3D Printing Spot

Updated by

William Stone


January 25, 2023

Key Takeaways

  • The extruder is one of the most critical subsystems of a 3D printer because it feeds the filament from the cold end through the hot end and out of the nozzle into the build area.
  • Some common issues with the extruder include a broken filament feed mechanism, a clogged nozzle, or a hot end that can’t maintain the right temperature.
  • There are two primary types of 3D printer extruders: a direct extruder and a Bowden extruder.

A 3D printer cannot function without a reliable extruder because it is one of the most essential components required for the printer to do what it needs to.

The extruder in a 3D printer feeds filament from a spool, heats it to produce melted plastic, and then pushes that melted filament through a small nozzle. Once the filament reaches the nozzle, it gets pushed into the hot end, which melts the material and deposits it as a printed object.

The functionality of a 3D printer extruder can vary based on the printer and extruder being used. We created this guide using our industry expertise and 3D printing experience, so read on to learn more about what the extruder does in a 3D printer.

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Table of Contents

What Does The Extruder Do In A 3D Printer?

The extruder is one of the most critical subsystems of a 3D printer. This component is responsible for feeding filament through the print chamber and into the hot end, where the filament is melted and deposited as an object on the build plate.

The extruder consists of several different elements to perform all of these functions. The feed mechanism takes filament from a spool and pushes it into the heating barrel, which is melted and forced through a small nozzle orifice to be deposited as an object.

The extruder’s design is one of the most critical aspects of a 3D printer’s design. The extruder must be able to feed and melt the filament, pushing it through the nozzle and into the build plate.

The three parts include a cold end, a hot end, and a nozzle to work correctly. It must be able to do all these things reliably and precisely to ensure good results.

How Does A 3D Printer Extruder Work?

The extruder is often considered a single piece of equipment but comprises many components. These components form a sub-system to move filament throughout the printer correctly.

These components include a cold end, a hot end, and a nozzle. Each piece has a specific function to allow the extruder to work the way it should.

Cold End

The cold end of the extruder is located in the upper area where the filament first gets fed and loaded into the printer. This is the first place to go with the filament when starting to print.

Finding the cold end depends on whether the extruder is a direct or Bowden extruder. The layout varies, and a direct extruder allows the filament to be pulled straight into the print head.

In the cold end, there is a motor and gearing system. There also should be PTFE tubing to feed the filament on all Bowden extruders.

After loading the filament into the cold end, it moves to the hot end.

Hot End

Next, we move on to the most critical area of the extruder. The hot end is where everything happens to create the 3D print using heat and filament.

Remember, the filament gets fed into the printer in the cold end, and this filament then gets pushed or pulled into the hot end. Once the filament gets here, there is a heated chamber to transition the filament into a print.

The hot end includes a filament feed tube, heatsink, cooling fan, heater blocker, power resistors, and a nozzle. The printing process is simple.

First, the filament goes through the tube, gets fed into the heat break, and passes the heatsink. While this happens, the cooling components are also running to monitor the temperatures for the filament to reach the nozzle.

The extruder must be able to take a spool of filament and feed it into the print chamber, melt the material, and push it through the nozzle and onto the build plate.


Lastly, the nozzle is located in the hot end, but it has an independent function to finish the printing process. This is the final output from the 3D printer.

The nozzle will release the molten filament through a tube into the build or bed area. The type of printer and extruder will impact how this gets released.

The nozzle size and speed can also vary based on the printing material used. But the function remains the same, providing the final result from the print.

Can You Use A 3D Printer Without An Extruder?

While a 3D printer would be very limited without an extruder, it is possible to make a 3D print without one in rare cases.

In the extruder, the filament pushes melted filament from the hot end of a 3D printer through a small nozzle and onto the build plate to print an object.

It’s difficult to imagine a successful session of printing without this function. We recommend avoiding 3D printers without an extruder because it's a crucial machine component.

What Does The Extruder Feed Through A 3D Printer?

The extruder feeds filament through the print chamber and into the hot end. Once the filament has been melted in the hot end, it is forced through a small nozzle orifice and deposited as an object on the build plate.

However, different 3D printers feed filaments through their extruders in different ways. This depends on whether the printer uses a Bowden extruder or a direct extruder.

However, all 3D printers and extruders can only use some type of plastic or filament to melt and create successful prints.

Why Is The Extruder Important In 3D Printing?

The extruder is one of the most critical components of a 3D printer. Without a properly functioning extruder, the machine can’t feed filament through the print chamber and into the hot end, which means it can’t print.

The extruder must be designed, manufactured, and tested carefully to feed the filament and push it through the nozzle correctly. It’s required for each step of the printing process too.

If there is a 3D printer without an extruder, it won’t be able to print anything.

3D Printer Extruder Problems

Because the 3D printer extruder is essential, users must be aware of the potential problems. These problems include a clogged nozzle, broken feed tube, or improper temperature settings.

Clogged Nozzle

When printing, any results that include under-extrusion can be attributed to a clogged nozzle. To fix this, the extruder gear must be removed so the filament can be pushed through the nozzle by hand.

Broken Feed Tube

A broken feed tube is a significant problem and likely requires a complete replacement. This is something that should be looked at by a professional before spending money on new equipment.

Improper Settings

The settings for a 3D printer are as crucial as anything. For example, the wrong temperature or retraction settings can result in extruder problems.

Double check the settings before all prints to ensure they are correct. The results can be costly if too many prints are made with improper settings.

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What Does The Extruder Do In A 3D Printer


William Stone

William Stone

William has spent 20 plus years in the custom manufacturing industry as a COO, CEO and Owner of various custom product businesses. His experience has exposed him to all types of manufacturing from die cast, die struck, injection molding, CNC machining, laser etching, engraving and of course 3D printing.

Learn more about William Stone

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