We can all agree that slicers are a vital part of 3D printing with how convenient they make the process by letting us configure our prints through a clean and user-friendly interface.
Alongside the ease-of-use they bring to the table, the constant evolution of slicer software brings new features that can directly increase print quality in various ways, which is always welcome considering it’s not always simple to print a model without any defects.
Today’s topic will be one such feature that can drastically reduce the defects on the outer surfaces of your prints – which is the combing feature in Cura.
So, what is combing in Cura?
Combing in Cura is a feature that causes the slicer to re-route all Travel Move instructions to stay within the bounds of the model, meaning that the printhead travels through the model even when there are shorter paths available.
Moving forward, we will be demonstrating combing in greater detail, lay out the steps for activating and configuring combing, and explore the areas where it’s a good idea to enable combing to increase print quality.
What is Combing in Cura?
Combing is one of the more underrated; yet powerful features of Cura, capable of increasing print quality by a great deal in the right situations.
The combing feature in Cura causes the printhead to only travel over the bounds of the model and avoid going through empty areas even when they are the shortest paths.
During combing, the printer does not retract the filament or perform a Z-hop unless a certain distance threshold is exceeded, as oozing and stringing stops being a problem with the printhead avoiding the empty parts of the printing area.
Next up, we will take a look at how you can activate and configure combing in Cura.
Activating Combing & Configuring Combing Settings in Cura
Activating and configuring combing in Cura is as easy as it comes, as it does not require you to configure anything other than a few selectable parameters.
Here is how you can activate combing in Cura:
- Click the Prepare tab on the top of the Cura window.
- Click the rightmost panel to bring up the Print Settings menu.
- Click the Custom button to see the print settings in detail.
- Type “combing” into the search box of the Print Settings menu.
- Click the dropdown menu next to the Combing Mode option, and choose the combing mode you wish to activate.
We will be covering the combing modes in greater detail in the upcoming section.
While there aren’t a lot of parameters you will need to configure for combing, let’s take a quick look at the available ones:
- Max Comb Distance with No Retract – This parameter sets the maximum distance the printhead will move without retracting the filament while combing is active. When set to zero, none of the combing travel moves will use retraction at all. If you have issues with blobs and zits, decreasing this distance is a good idea, as retracting the filament can often prevent these problems at the cost of prints taking longer.
- Avoid Printed Parts When Traveling – Enabling this setting causes the printhead to avoid the already printed parts during travel moves. While enabling this setting can cause the printing process to take longer, it can be helpful to combat imperfections on the print.
- Avoid Supports When Traveling – Enabling this setting causes the printhead to avoid supports during travel moves. We recommend keeping this enabled in general to circumvent damaging the supports, as supports are usually not too sturdy.
Cura Combing Modes – Not in Skin vs. Within Infill (Infill Only) vs. All
Choosing the correct combing mode is a vital part of how well the feature will work on your print, which is why it’s significant to know the differences between them and make the right choice.
To start, let’s take a look at the functionalities of each of these modes to have a better idea about how they affect the combing feature.
- Not in Skin – Choosing this option causes the printhead to avoid combing over the top skin of the models. If you are experiencing scars on the top surface (large and flat surfaces in particular) of your prints while combing is active, we recommend experimenting with this option.
- Within Infill – Choosing this option causes the printhead to avoid the skin and the walls, essentially only allowing it to comb over the infill. Within infill is the best choice for reducing the number of imperfections on the skin and the walls of your model, at the cost of the printing process taking longer.
- All – This is the default option for activating combing, where the printhead will comb over the entire model.
Out of the three options, we recommend within infill for general usage.
When the within infill option is active, the advantages of the combing feature compared to having it inactive are:
- The elimination of stringing by causing the printhead to avoid empty areas
- Lower print time due to the printhead not having to retract while the printer prints the infill
Since this option also prevents the imperfections that enabling combing may cause by avoiding the skin and the walls (or retracting before going over them), it’s the best option overall in most scenarios.
When Should You Use Combing in Cura?
Despite being a powerful feature, combing in Cura isn’t something you should enable and forget about, as it can also be detrimental to your prints in some scenarios.
The main ideas behind the combing feature are to eliminate stringing by preventing the printhead from moving through empty areas where strings can form and reduce print time by minimizing the number of retractions the printhead performs, making either of these valid reasons for using combing.
As combing can also cause imperfections on the surface of your models due to the oozing that takes place as a result of the printhead not retracting the filament, remember that it’s not a magic switch for improving your prints.
Since you can enable and disable combing with the click of a button, feel free to experiment with it to find out what works best.
Should You Use Combing with PETG?
As PETG behaves quite differently than PLA, a common question is whether the combing feature is suitable for usage with PETG filament.
As PETG can get even more stringy than PLA, enabling combing in Cura is usually a good idea to eliminate or reduce the stringing issue as much as possible.
We recommend using the within infill mode in Cura for printing PETG, as PETG can easily cause blobs on the surface due to excessive oozing if the printhead travels through these areas without retraction.
Combing in Cura is one of the most impactful features you can enable, and considering that it requires almost no configuration, it’s definitely worth experimenting with it.
While it’s not a setting you should always keep active, the positive impact it brings to the table in eliminating stringing from a model is undeniable, considering that you activate it in the right situation.
We hope that you have enjoyed this read, and we will see you next time!
Mike started his 3D printing journey with the Anet A8 when it first came out back in 2017, and has been obsessed with 3D printers ever since. Nowadays, he primarily uses his Ender 3 to print functional parts that make his life more convenient whenever possible.