How to Set Nozzle Size & Line Width (Extrusion Width) on Cura? (Detailed)

While slicers make our life much easier for everything related to 3D printing, correctly configuring them is vital for achieving high-quality prints.

Even though configuring these settings is usually straightforward, thanks to the clean interface of the slicer software, it’s also possible to get lost in them due to the sheer amount of parameters.

Due to the number of questions we have seen about two nozzle-related settings, in particular, we decided to cover them in greater detail to make it easier for everyone to configure it correctly.

So, how to set nozzle size and line width on Cura?

To set the nozzle size on Cura, click the tab with the nozzle size information on the main screen and choose the target nozzle size from the dropdown menu.

For setting line width (extrusion width) on Cura, click the tab with print settings on the main screen, go to Custom, and find the Line Width input by using the search box.

While finding both of these settings should be straightforward if you are familiar with the slicer, we will cover both of these settings in greater detail moving forward to make things as detailed and understandable as possible for everyone.

How to Set Nozzle Size on Cura?

The nozzle size setting isn’t grouped with the rest of the print settings, making it slightly harder to find than most other settings if you don’t know where to look.

Here are the steps for setting nozzle size on Cura:

  1. Click the Prepare tab located at the top of the Cura window.
  2. Click the middle tab below, which should contain information about the nozzle size and the filament. You should see the name of your printer on the left of this tab and print settings such as infill ratio on the right.
  3. Select the nozzle size of your printer in the Nozzle Size dropdown menu, which should automatically save the new nozzle size value.

In three simple steps, you have successfully set the nozzle size on Cura.

As nozzle size is often automatically set to the correct value by Cura depending on the printer you have selected, you will only need to change it if you have modified it.

If you don’t know the nozzle size value you should be using – we highly recommend consulting the manufacturer’s website or the manual of the 3D printer.

How to Set Line Width (Extrusion Width) on Cura?

The line width setting resides in the Print Settings section of Cura, together with almost every other value you can configure.

To set the line width (extrusion width) on Cura, follow these steps:

  1. Click the Prepare tab.
  2. Click the third tab below, which should contain information about the print settings.
  3. Click the Custom button.
  4. Type “Line Width” into the search box to find the Line Width input box.
  5. Set the line width by inputting the desired value into the Line Width input box.

Alternatively, you can click the Quality tab instead of using the search box to bring up the Line Width setting, but you first need to make it visible by clicking the Gear icon next to the tab.

The changes should take effect as soon as you input the value, without the need to do anything else.

Next up, we will dive into how you can find the correct line width for your printer, as this figure isn’t quite set in stone as nozzle size is.

How to Calculate the Value for Line Width (Extrusion Width) in Cura?

Line width is often calculated by multiplying the nozzle size with a percentage value that varies depending on the use case.

For the most part, the recommended value for line width (extrusion width) is equal to or slightly larger than the nozzle size, with values between 100% and 120% being considered optimal.

Since we observed the best results by using 120% of nozzle size in most scenarios, we recommend calculating line width with the same formula.

So, to calculate the value for line width, find your nozzle size, and multiply it by 120%.

Moving forward, we will take a look at how different line widths affect the printing process.

Effects of Line Width (Extrusion Width) on the Printing Process

As line width (extrusion width) determines the amount of plastic the printer extrudes, it causes a considerable amount of observable changes to the printing process in the form of print time, model detail, and object stability.

Print Time

The most apparent effect of line width on the printing process is on print time.

Print speed decreases as the line width increases, as thicker lines mean more plastic being extruded, causing the printhead to spend less time moving.

Model Detail

Another effect of line width is on the model detail.

The model looks much sharper as the line width decreases, as thinner lines allow the printer to print the model with a higher level of detail.

Object Stability

The last effect of the line width on the printing process is the stability of the object.

An increased line width causes the object to become much more stable, as the thicker lines of filament do a better job of supporting the object and keeping it sturdy.

Individual Line Width Settings on Cura

Alongside the primary line width value, there are sub-values you can modify to have a greater level of control over the line width settings in Cura.

  • Wall line width – Wall line width determines the width of a wall line. If you wish, you can configure outer and inner walls separately for this setting.
  • Top/Bottom line width – Top/bottom line widths determine the width of the bottom and top layers.
  • Infill line width – Infill line width determines the width of all infills.
  • Skirt/Brim line width – Skirt/brim line width determines the width of both skirt and brim lines.
  • Initial layer line width – Initial layer width determines the line width for only the initial layer.

What Should Be the Line Width (Extrusion Width) for a 0.4mm Nozzle?

Calculating the line width (extrusion width) for a 0.4mm nozzle is an easy task with the recommended formula we have mentioned earlier, which is to calculate 120% of the nozzle size.

In this case, the calculation would be:

0.4 * 120 / 100 = 0.48 (mm)

So, the line width for a 0.4mm nozzle should be 0.48mm.

Wrapping Up

Setting both nozzle size and line width in Cura are pretty straightforward tasks, as long as you know where to find the inputs for them.

Correctly configuring these settings is also as easy as inputting values that you can easily find without spending too much effort and time, unlike many other slicer settings that may require hours of experimentation.

As the incorrect configuration of these settings can quickly ruin a print, make sure to double-check them after inputting the values to avoid facing issues down the road.