What Is Retraction in 3D Printing — Best Retraction Settings for 3D Printing
A common occurrence during 3D printing is over extrusion. This is when the heat of the nozzle from your print head moving from one point to another during printing, combined with any pressure in the hot end results in some excess filament being forced out.
As a result of this, faint strings are left along the printhead’s path between points. To get rid of this annoying case of stringing, retraction is the best feature to get the job done.
Adjusting your retraction settings in 3D printing is quite essential so you don’t have to deal with troubleshooting poor print quality in certain models. Some of the best retraction settings that can be adjusted to improve your printing process will be discussed in this article.
What Should You Know About Retraction?
Designed to optimize the amount of filament the nozzle releases and the speed at which it recoils, retraction is one of the best features available in a lot of 3D printers. It earned the name “retraction” due to its ability to retract unwanted filament from the nozzle, and will immediately retract any additional filament that is released once the specified amount of filament has been released by the nozzle.
Its importance is greatly acknowledged in the printing process as it prevents the disruption of the finished object’s size and dimensions that could occur as a result of excess filament or stringing. By stopping the melted or semi-melted filament from coming out of the nozzle, retraction naturally protects the finished printed object against stringing.
This is why using the right retraction setting is the best thing to do. The wrong retraction setting applied to a 3D printer may yield negative results like a clogged nozzle if the filament distance is too high.
You can enable and tune the retraction feature when preparing a model for printing in a slicer like Cura or PrusaSlicer, and with the right settings, retraction helps you prevent stringing, blobs, zits, and several other print quality problems related to extrusion.
Best Settings for Retraction in 3D Printing
- Distance: One of the most important retraction settings has to be distance as it is the length of filament that is pulled back by the extruder every time retraction occurs. The amount of time a retraction might take is largely dependent on how long the distance is.
This means that the longer the distance is, the more time a retraction might take and you are less likely to experience stringing. However, this doesn’t necessarily mean you have to use the highest retraction value as it might cause the filament to retract too much and the hot end or nozzle to clog.
Since there is no perfect value as it depends on your extruder configuration, hot end, etc, you can try to tweak the default distance setting in 1-mm increments until there are no more stringing, clogs, or other issues. Note that, a typical retraction distance ranges from 2 to 7 mm.
- Speed: Another important retraction setting is speed and it determines how quickly retraction is carried out. Due to its ability to influence print time and how effective retraction is at eliminating stringing, it is a setting you want to get right during the printing process. Making use of too slow a speed, e.g. a 20mm/s speed, will not be able to relieve the pressure fast enough to prevent excess material from exiting the nozzle; and the use of too high a speed can be the cause of issues like the breaking of the filament inside the hot end, leading to stringing. The ideal speed to make use of is the fastest functional speed to reduce stringing and print time i.e. your slicer's default retraction speed is most likely between 30 and 60 mm/s. However, if this value still doesn’t work for your printer, you can adjust the speed in 5 mm/s increments.
- Minimum Travel: The minimum travel setting simply connotes how frequently retraction occurs in a specific area. When set correctly, it prevents nozzle clog that could occur from two retraction movements happening close to each other and causing a constant reversal of the filament motion in a short amount of time.
The minimum travel distance is achieved by requiring the nozzle to move a certain distance before it is allowed to perform retraction again. A setting like this is useful if you are printing a model with many close-by separate locations where the occurrence of retractions could be as close as a hairbrush.
You should know that a larger minimum travel distance might increase the likelihood of stringing by preventing retractions from occurring, but it also reduces the chances of a nozzle clog. The ideal minimum travel distance is usually set at 1-2 mm, but if it doesn’t work for you, you can adjust the value by 1 mm increments.
- Enable Combining: Enabling this setting prevents the hot end or nozzle from moving over holes. This allows material remains to be avoided in the faces seen from the internal parts of the pieces. Apart from performing the retraction, this setting can also facilitate the retraction of the program of lamination used in your printer.
- Z-axis Elevation: The z-axis works hand in hand with retraction, this is because at the same time retraction occurs, the hot end or nozzle moves on the z-axis or indicated distance. The z-axis elevation setting’s importance stems from the need of making pieces with many details and small areas of great detail to avoid leaving traces of material right in that area. The ideal adjustment for this setting, especially if it’s one you need during the printing process, is using the same distance value as that of the layer height.
How Do You Get the Best Settings for Retraction?
There are different ways to go about finally getting the best retraction settings for your 3D printer, and you can choose any of these methods to ensure a top-quality printed object to your taste.
- Trial and Error: To get the best suitable retraction settings, you can start by printing small objects that can be printed in a short period, just for retraction tests. Change the retraction speed and distance step by step to note at which value the printer’s performance is top-notch. Once you are completely satisfied with the results of the retraction tests print, you can now start printing the actual object you want.
- Changes between Materials: For every filament material that you use, there are different retraction settings so you have to calibrate the retraction settings according to each filament material you use like PLA, ABS, etc. If you are still experiencing issues even after changing retraction settings, try using the filament materials that are comparatively flexible as they will also work better on the low retraction speed.
Note that the retraction settings will be different and this is depending on whether or not you have a Bowden or a Direct Drive setup.
How to Avoid Stringing in Flexible Filament with the Best Retraction Settings
Flexible filaments, while prone to oozing and stringing, are used because of their non-slip and impact resistance properties in 3D printing. Their oozing and stringing problems can easily be fixed by making use of the appropriate printing settings.
- Firstly, enable the retraction settings each time flexible filament is used during your printing process.
- Secondly, set up a perfect temperature because high temperatures can cause the filament to melt quickly and start dropping.
- Then do a test print by adjusting the retraction speed and distance because flexible filaments are soft and a little difference can cause stringing.
- Go ahead to adjust the cooling fan with respect to the printing speed.
- Finally, focus on the flow rate of the filament from the nozzle. Flexible filaments usually work perfectly well at a 100% flow rate.
Best Cura Retraction Settings on Ender 3
There are different retraction settings for Cura on Ender 3 printers but the ideal and expert choices for these settings include:
- Enabling: Enable retraction on your printer by going to the “Travel” settings and checking the “Enable Retraction” box to enable it.
- Speed: Test your print at 50 mm/s and you can decrease by 10 mm/s if you are still experiencing issues until you notice improvements, then you can stop decreasing.
- Distance: The retraction distance on this printer should be between 2 mm to 8 mm. You can start at 5 mm and then adjust it until the nozzle stops oozing.
- Max Retraction Cont: the ideal choice for this setting is “10” but you can change or adjust it only when you are still encountering issues during your printing process.
You can implement a retraction tower to calibrate the best retraction settings on your Ender 3 printer by using increments of each setting per tower or block to gauge which one gives the best quality. For example, you can do a retraction tower for distance to start from 2 mm all the way up to 8 mm to see which of the retraction distance setting gives the best result.
Retraction is one of the common features in 3D printers that help to ensure your finished object is printed in the best possible and suitable quality. However, to achieve this, you must learn the best possible retraction settings for this to work. This article provides you with the ideal choices to make for a smooth and top-notch printing process. Feel free to contact us for more information or if you have more questions.