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What Is The Extruder On A 3D Printer

What Is The Extruder On A 3D Printer | 3D Printing Spot

Updated by

William Stone


January 6, 2023

If you plan on using a 3D printer successfully, you will need a reliable extruder and a little knowledge to understand exactly what it is.

Without a reliable and high-performing extruder, it would be impossible to create 3D prints. This essential part of the printer allows users to do various tasks to ensure they can get the most from the printer.

The extruder on a 3D printer has a cold end, and a hot end that pushes the material from the filament reel through an opening called a nozzle. The nozzle melts and extrudes the material, so it cools down and solidifies into layers to form your print. Every printer has an extruder.

When using a 3D printer, you will come in contact with an extruder to execute all of the primary tasks to create a finished print. This starts by loading the filament into the cold end, where it will maintain pressure and feed the filament into the hot end for melting and extruding. We will explain everything you need to know about what an extruder on a 3D printer is below.

3D printers are complex machines and we have compiled all the available research needed to understand what an extruder is and how it works. Continue reading to become an expert for your own printing projects.

Table of Contents

What Is The Extruder On A 3D Printer?

A 3D printer extruder is a component that feeds filament through the hot end and into the nozzle.

The extruder is made up of various parts that are absolutely essential to the performance and success of any 3D printer.

In this printer area, many different things happen, and the extruder is responsible for a few tasks. This is because the extruder is made up of two different ends.

When the printing process begins, the extruder is responsible for moving the filament through the printer at each step. This is done with both the cold end and the hot end of the extruder.

What Does The Extruder Do On A 3D Printer?

The extruder is extremely important and does many things that make it possible to create high-quality 3D prints.

The extruder will begin by loading and feeding the filament through the printer. As it does this, the extruder will create and maintain pressure to keep the filament steady for a precise print.

Once the filament moves through the cold end, it will reach the hot end, where the high temperatures mold and melt the filament material to create the print.

You will see the material extrude through the hot end to create a finished print for your project.

What Makes Up The Extruder?

The extruder is the tool that takes the filament and pushes it through a nozzle, which is where the filament comes out. Many components are included with the extruder, including a cold end and a hot end.

Below we will explain the significance of each along with the components that make up both of these parts of the extruder.

Hot End

The hot end of your extruder is responsible for doing the heavy-duty work to create a print. This means it will feed, melt, and extrude the material to make a finished product. This is done with five key components listed below.

Filament Feed Tube

The feed tube will move the filament into the hot end or simply guide the filament through the process. The exact function of this tube varies based on the type of extruder being used.


The nozzle is arguably the most essential part of the hot end because this is where the molten filament builds pressure and extrudes.

The nozzle opening releases the final print onto the build plate of your printer to cool down and take form.

Heat Blocker

The heat block is a simple aluminum component that holds the heater cartridge and thermistor together while they run the filament.

Heat Cartridge

The heating cartridge will create heat in the hot end. It is completely responsible for building the printer up to the proper temperature to melt and form the filament into a 3D print.


Lastly, there is a heatsink that is responsible for keeping the temperature stable and cool enough to avoid overheating.

Cold End

The cold end of the 3D printer extruder is the upper portion where the filament gets fed into the printer for printing. The exact layout will vary based on the type of 3D printer extruder you are using too.

You will find three primary components in the cold end of every 3D printer extruder.

This includes a motor, drive gear, and idler, and each has a unique function to make the printing process more efficient.


In the cold end of the printer, the extruder will have a stepper motor that assists with pulling the filament. You will need the motor for this movement to occur.

Without the motor, it becomes impossible to put filament into the printer to create a 3D print.

Drive Gear

The drive gear is responsible for guiding the filament from the cold end into the printer's hot end.

Depending on your machine, this gearing system is mounted on the side of the printer’s frame or the printer head.

This gear is right next to the motor to make it easier for the filament to move through the printer. You should regularly clean this gear to ensure this process is smooth as can be during every use.


The idler is typically a tube of some sort, depending on the extruder type being used. This is critical when moving the filament into the hot end with precision and accuracy.

However, you won’t need a tube when using a direct extruder. The Bowden extruder requires this tube to work properly.

Types Of 3D Printer Extruders

A few different types of 3D printer extruders are available on the market. The extruder is essential for all printers; you will not see a printer working without one.

The three extruder types include a direct extruder, a Bowden extruder, and a dual extruder. We take a look at each below to highlight the key differences.

Direct Extruder

The direct extruder is advanced and typically gets installed by using the hot end on one side to push the filament towards the nozzle. This is where it gets its name from.

This consolidates where all of the filament processing happens to make it straightforward with less movement throughout the machine. You can expect a better extrusion by using this part.

It also provides much faster retraction and allows you to use many more filament options than other extruder types.

The downside is the complex maintenance required to keep your extruder clean and your 3D printing running well. It also is heavier and requires more power while adding additional wear and tear on the belts and bearings.

Bowden Extruder

The Bowden extruder is a bit different for a few reasons. First, the design differs because the extruder attaches to the frame of the printer and acts as a method to feed the filament into the Bowden tube.

The Bowden tube connects the cold and hot ends, so as the filament pushes through the printer, it reaches the hot end. It is not always the preferred choice, but it is a lightweight alternative and prints at a faster speed.

It also tends to last longer because of fewer vibrations, so the prints are a bit more precise. But you will need to upgrade your motor to handle this extruder, which cannot handle as many filament types.

Dual Extruders

Dual extruders are used on unique 3D printers requiring multiple extruders to complete the job. They are used for special projects and are not as practical for the average 3D printer user.

You will have two dependent or independent extruders when using dual extruders. Both are effective, but they work differently.

The dependent extruders will keep the nozzles in contact during the entire printing process. This is a bit tedious because the risk of errors or damages occurring during the printing is higher than usual.

The independent extruder is more versatile and efficient because it can work on multiple tasks simultaneously.


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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What Is The Extruder On A 3D Printer

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