Stringing and blobbing are perhaps the first things that come to mind when we think of issues related to 3D printing, mainly because they are capable of entirely ruining how a 3D printed model looks due to all the unnecessary plastic that shouldn’t be there at all.
While the correct configuration of many different parameters is required to eliminate stringing and blobbing, the retraction feature is, without a doubt, the one that stands out as the primary way to combat these issues.
Due to how frequently stringing and blobbing troubles 3D printing enthusiasts, today, we have chosen the topic of retraction settings, particularly for printing with PLA filament, where we will explore the most optimal way of configuring these settings for a healthy printing process.
So, what are the best retraction settings for PLA?
Even though experimentation will always yield the best results due to differences in hardware, here are the retraction settings of our recommendation that can act as a starting point for printing PLA successfully:
- Retraction Distance – 5 mm (for Bowden extruders) / 1 mm (Direct Drive)
- Retraction Speed – 45 mm/s
- Retraction Minimum Travel – 1.5 mm
Next up, we will be analyzing each of the three primary retraction-related parameters in more detail to find the optimal values for PLA, go over the necessary steps for configuring retraction for PLA in Cura, and discuss the effects of too much retraction.
What Are the Best Retraction Settings for PLA?
Configuring the retraction settings as optimally as possible is, more often than not, a tricky subject that requires an extensive trial and error process, especially considering that there are a few different variables that need to work together.
As each of these variables is equally significant for the retraction feature to fulfill its duties, in this section, we will be going analyzing them individually in detail.
The retraction speed determines how quickly the printer pulls the filament back into the extruder from the nozzle (and how quickly it pushes the filament back out unless you specify a different value for the priming speed).
A reasonably common retraction speed value of 45 mm/s while printing with PLA yielded optimal results in our tests, allowing us to have quick retractions and print various objects without experiencing neither under-extrusion nor over-extrusion symptoms.
To fine-tune this value, we recommend pushing it as high as possible (in increments of 1 mm/s) to minimize the amount of time the retractions take until you reach a point where the high speed causes filament grinding and potentially nozzle blockage.
The retraction distance determines how far back the printer pulls the filament back into the extruder from the nozzle when a retraction is triggered.
A retraction distance value of 5 mm for Bowden extruders and a retraction distance value of 1 mm for Direct Drive extruders should do the job for printing with PLA, pulling the filament back to an excellent spot to prevent oozing without putting too much strain on it.
To fine-tune this value, we recommend going up (if you’re facing over-extrusion) or down (if you’re facing under-extrusion) in increments of 0.1 mm while ensuring that you don’t set this value to a higher figure than the distance of your 3D printer’s nozzle.
Retraction Minimum Travel
The retraction minimum travel value determines the frequency of retractions based on the distances of the travel moves the printhead performs during the printing process.
A retraction minimum travel value of 1.5 millimeters is considered pretty standard, as this value is affected more by the travel paths of the model you’re printing rather than the filament type, meaning that it will work just fine for PLA.
For fine-tuning purposes, you can modify this value in increments of 0.1 mm, and try to get it as high up as possible until you start facing over-extrusion due to the lack of retractions, which will prevent unnecessary retractions and speed your print up.
How to Configure PLA Retraction Settings in Cura?
Cura makes it a very straightforward process to configure and save retraction settings into distinct profiles corresponding to different filament types, which is especially handy for those who regularly switch between filaments.
By following the steps we have outlined below, you can configure and save your retraction settings specifically for PLA filament in the Cura slicer:
- Navigate to the Prepare tab in Cura.
- Click the middle pane, which displays your currently selected filament profile and nozzle size.
- Click the Material dropdown menu, and choose PLA from the Generic tab.
- Switch to the right pane, displaying information about the current print settings.
- Type “retraction” into the search input.
- Click the “three lines” icon next to the search input, and choose the All option to make all settings visible.
Following these steps will load Cura’s defaults for PLA, which allows you to override these defaults with your custom retraction configuration while keeping all the other default settings.
Once you’re done with the configuration, you can save your overrides into a new print profile (Profile -> Create profile from current settings/overrides) and load them back whenever you wish to use these settings for other prints.
What Are the Signs of Too Much or Too Little Retraction While Printing with PLA?
While retraction is a very efficient feature for reducing and preventing the appearance of stringing and blobbing on your 3D printed models, too much of it will cause a different set of issues that affect the printing process negatively.
Here are the most common signs you will observe if you are using too much retraction while printing with PLA filament:
- Under-extrusion of the plastic and the appearance of gaps and holes on the print as a result
- Partial or complete jam of the 3D printer nozzle
- Filament grinding due to the high-speed and long-distance retraction that occurs frequently
On the other hand, here are the common signs that too little retraction will bring to the table while printing with PLA:
- Over-extrusion of the plastic and the appearance of stringing and blobbing as a result
- An overall loss of quality on the surface of the 3D printed model
- Filament gathering on the nozzle during the travel moves
Optimal PLA Retraction Settings for Creality Ender 3 (Pro/V2)
As the optimal retraction settings vary for different printers just as they do for different filament types, let’s take a quick look at the optimal PLA retraction settings for Creality’s Ender 3, the most commonly used 3D printer on the market right now.
Below are the retraction settings we recommend using if you plan on printing PLA filament with your Ender 3, Ender 3 V2, or Ender 3 Pro:
- Retraction Speed – 45 mm/s
- Retraction Distance – 5 mm (Bowden) / 1 mm (Direct Drive)
- Retraction Minimum Travel – 1.5 mm
You may have noticed that the retraction settings we have specifically shared for the Ender 3 are exactly the same as the settings we have shared throughout the article, which is due to us conducting all of our tests on the Ender 3 as the most commonly used printer on the market.
Even though PLA is one of the less challenging filament types to print with, correctly configuring the retraction settings is still a vital part of a successful printing process where problems like blobbing and stringing don’t trouble your 3D printed model.
To quickly recap, we can say that a retraction speed of 45 mm/s, a retraction distance of 5 mm (2 mm for direct-drive extruders), and a retraction minimum travel value of 1.5 mm should provide a suitable configuration for printing with PLA filament.
As always, finding the values that work best in your case can require some experimentation and tinkering of these values, which is why we highly recommend running some test prints before starting larger projects.