The Ender 3 is exceptional at pushing filament, but stringing can still be a problem. Read on to find how to perfect your Ender 3 retraction settings and clear the cobwebs!
Retraction, pulling filament back during traveling, takes pressure off the nozzle. Every 3D slicing software we know of has retraction settings, and we’ll be going over these settings to help you get to a “no stringing” zone with all of your prints on an Ender 3.
We will focus on the Ender 3 from Creality with the Cura slicer. Follow along as we activate the relevant settings for retraction (under “Material”) and review the recommended values for each.
If you don’t see some of these settings in your version of Cura, find the Material section in your settings and click the gear icon. This will bring up the “Setting Visibility” dialogue box. Check all of the boxes and, after hitting “Close”, you’ll be able to see all of the material settings under “Printer Settings”.
This is one of the simplest settings we have. It’s basically the switch that turns on the ability of the printer to do retraction movements. With it off, there are no other settings for retraction. With it on, we have settings we can adjust to get the best possible print.
The Ender 3 works well right out of the box, but you will get stringing without tuned retraction settings.
Retraction distance is the amount of filament the extruder will retract from the nozzle.
For example, if this setting is set to 7 mm, the extruder will pull 7 mm of filament out of the Bowden tube. When the printer is ready to lay down more filament, it will move the same 7 mm of filament back into the Bowden tube. This momentary pressure relief can stop oozing and prevent stringing. The push of filament back into the Bowden tube after retraction will prepare your Ender 3 to print again. This is called “priming”.
It’s good to start with a setting of 5 mm and adjust it up or down by 1 mm until you have it just right. The goal is to get the lowest possible number while reducing as much stringing as you can. A good range is 3 to 7 millimeters. Too low of a number won’t reduce stringing, too high and you could cause damage to your filament and increase your print time.
The potential damage to the filament is caused by the gear on the extruder. It has small teeth that dig into the filament to move it forward or backward. Moving the filament back and forth too much over the same area can cause damage to the filament, which will eventually cause it to slip.
Retraction speed is how fast the extruder pulls the filament out of the Bowden tube and nozzle. This is typically in millimeters per second (mm/s). The higher the setting, the faster the movement. The trade-off here is that you need to get the filament out of the nozzle quickly, but the faster you go, the more potential damage you could cause to your filament.
In Cura, retraction speed can be broken down into two different speeds:
In layman’s terms, these two settings define speed out and speed in. These settings aren’t essential to change; setting Retraction Speed will cause it to copy that speed into both of these options.
Why break retraction speed into two components? You may find that your extruder does more damage on priming than retraction, so a lower speed here will help protect your filament.
Start with a setting of around 50 mm/s. If you’re seeing some filament dust around your extruder, it’s best to slow your speed down. The dust is caused by the grinding of the extruder gear on the filament. Conversely, if you don’t see any dust, you can try to speed it up a bit by raising this value. The faster speed will reduce your print time.
This setting can help you compensate for material that was lost through oozing. When the printer primes after retraction, it pushes whatever amount is in this setting.
The recommendation here is to work on your retraction distance, getting it to a number that prevents additional material loss and then you can leave this setting at 0.
This setting adjusts the number of maximum retractions on a specific area of filament. This option protects your filament from damage by retracting and priming too many times. Since the extruder is using a gear with teeth that dig into the filament to push and pull it, the more your extruder retractions occur on one specific piece of filament, the more damage can occur.
The original setting in Cura is 100, which is really too high to protect your filament. A good number to start with is 10. This is low enough to help protect your filament and high enough that the slicer won’t enforce it. If the slicer would exceed this amount, it turns off retraction for the length of filament listed in the next setting.
Minimum Extrusion Distance Window allows you to specify the length of filament the Maximum Retraction Count is enforced on. For example, if you set the Maximum Retraction Count to 5 and the Minimum Extrusion Distance Window to 10mm, the extruder will only allow 5 retractions over a 10mm piece of filament. Any retraction command after that will be ignored.
Rather than try to count up how many retractions you could get over a specific length of filament, we recommend you keep this number close to your Retraction Distance, then work with your Maximum Retraction Count to ensure you don’t damage your filament.
This setting is a checkbox. Enabled, it stops retractions when moving within supports. You’ll still get stringing, but it will only be within the support structure.
Why allow the stringing in your support structure? Remember that retraction is a balance; retraction is good, but too much will increase print time and can damage your filament. The best use of retraction is to protect your print, so don’t worry about the supports.
We recommend you turn this on. It will help protect your filament and speed up print time, the only downside being some extra stringing within the supports of your print.
These settings are used to set retraction distance and speed when the nozzle goes into standby mode, which is used for multi-nozzle printers. Since the Ender 3 only has one nozzle, leave these at the default settings of 16 mm and 20 mm/s respectively. Cura doesn’t like a setting of 0 in either one of these values.
Found in “Travel”, combing mode tells the slicer to keep the nozzle within printed areas when moving from point to point. There are four settings for combing mode: Off, All, Not in Skin, and Within Infill.
We recommend going for Within Infill. It will reduce your number of retractions by keeping the nozzle within the infill areas when moving from one point to another. This can increase your print time but will protect your filament.
As a quick summary, here again are our condensed recommendations for your Ender 3 retraction settings:
(Lead image source: FiendFyre_62442 via Reddit)
License: The text of "Ender 3 Retraction Settings: All You Need to Know" by All3DP is licensed under a Creative Commons Attribution 4.0 International License.
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