What Is Retraction?

When 3D printing items, the hot end is always under pressure with the filament being extruded from it. This is true even when the machine is not actually printing something, and simply traveling to a new point-the pressure applied can make the filament ooze.

Retraction aims to solve this problem by pulling back the filament for a small distance when the nozzle is moving, creating a vacuum which helps to stop any leaks of the melted filament. You can start dialing in the sweet spot where you eliminate strings and blobs by adjusting settings in your 3D printer.

How to Set Retraction?

You will need to use your 3D printing software in order to adjust your retraction, whether you want to enable/disable the function, or just tweak some of the parameters.

Explanation of Key Parameters

To help you navigate your specific 3D printing application, while also adjusting your 3D printing retraction settings accurately, we will explain the concept of the most common parameters. Just keep in mind, that depending on your specific program of choice, these options can be called different things and some applications might not have all of the options listed below.

Retraction Distance

The actual distance for retraction is a common parameter for most slicing applications. It simply defines how far the filament is drawn back from the extruder. You can experiment with it, but you can also look up online what works well for your model and try what other people have found as a good baseline.

Retraction Speed

Next up, we have the speed of the retraction, which is a parameter that determines just how quickly the filament is retracted. The faster this speed is set to be, the cleaner you will typically experience your prints but it will also increase the risk of snapping the filament. On the other hand, a speed setting that is too slow can ooze 3D printing material from time to time.

Minimum Travel Distance

As the name suggests, this parameter controls what the minimum acceptable distance a retraction is triggered. On short moves where the extruder will only be travelling a short distance, it can be unnecessary to retract the filament, so this prevents unnecessary retraction on very short travels. It is common to use 0.5–2.0 mm for this.

Z Hop

This parameter controls whether the 3D printer will attempt to lift the nozzle slightly when it travels. Enabling this function can prevent your nozzle from hitting your 3D printed objects when in motion, but can also increase the probability of stringing. We advise you to test out both options to see what works best for your printer.

Retraction Settings for Different Extruders

1. Direct Drive Retraction Settings
   
   The Direct Drive extruder only requires a shorter distance, such as 0.5–2 mm, as it is mounted directly above the hot end. Because of this, the distance from the gear itself and down to the melt zone is short, meaning a short distance will be plenty to create the vacuum in the nozzle.
   
2. Bowden Extruder Retraction Settings
   
   A Bowden extruder generally requires a longer retraction distance, such as 4–7 mm, due to its longer pipeline and greater elasticity. This is because the slack is the first “part” to be retracted and only then the actual pull will take place.
   

Retraction Settings for Different Materials

It is also important to consider what 3D printing material and 3D printer you are using. Different materials with their own unique properties require slightly different settings. So if you experience that your PLA filament causes oozing, you can use the table below as a solid base for perfectly tweaking your 3D printer and 3D printing filament for the best possible 3D printer retraction settings. We recommend that you only change one thing per print in order to validate the expected effect.

(PS: The following are just some comprehensive reference Settings, as different printers have different settings and conditions. )

Typical Symptoms of Retraction Failure

Many beginners and intermediate hobbyists often have trouble identifying whether their problems are caused by retraction failure or some other aspect on the printing process. And for good reason, the topic can quickly become quite complex. So we have created a short guide to help you figure out whether your symptoms could be related to retraction failure.

Stringing / Oozing

Once you have seen this problem in your own prints, you will understand both of the words instantly. Stringing and oozing is what happens when you get long, thin lines of filament that does not follow the expected layer pattern. They can be caused by a number of different things, but relating to retraction there are typically three main reasons.

1. Stringing can happen because the retraction distance is not great enough, which is the most common issue people have. As we mentioned earlier, if the filament is not pulled far enough back into the nozzle, the filament can leak out.
   
2. Another issue is that your retraction speed is too slow. If the retraction is not quick enough, won’t relieve the pressure in the nozzle effectively to allow the molten filament to stretch and turn into long strings.
3. While not strictly a retraction issue, you can also experience stringing if your print temperature is too high, as the filament becomes more “runny” and prone to stringing.

More solutions of string, please refer: 5 Easy Ways to Prevent 3D Print Stringing.

Blobbing / Zits on the Surface

Another common problem is what we call blobbing, which is categorized by small bumps or blobs on your printed objects. This problem tends to most commonly happen at the start and end of a perimeter, since it is related to the restart of the extrusion. The reasons include:

1. Extruding too much after retraction is the most normal cause of this, as the printer tries to push out too much filament when beginning to print again after having travelled. Typically you will need to lower the retraction distance or the extra restart distance, depending on your slicing software.
2. The actual speed of retraction can also be too high, as it can knock the filament into the melt zone by accident which increases the pressure and creates the blobbing effect.

Bonus tip: If you have not enabled “Coasting” or “Wiping” in your slicer, activating these features can often help remove the blobbing artefacts, as they adjust the extrusion behavior to help avoid blobs.

How to Run Retraction Tests to Find the Perfect Values

In order to find the best values, whether for your TPU retraction settings, or PLA retraction speed, you follow this step-by-step guide to dial, in order to learn how to reduce stringing 3D printing artefacts.

1. Dry filament: This is very important because too much moisture may give you a lot of stringing and poor extrusion.
2. Print a temperature tower: You can try to print a temperature tower that gradually changes the printing temperature according to the height of an object to find an optimal value. This can help identify the best extrusion temperature for your specific filament.
3. Use a retraction tower:  Next, you can try a specific retraction tower model to help you adjust the distance at a fixed speed, As the printer goes layer by layer, you will then need to observe the distances that produces the least amount of stringing.
4. Fine-tune the speed: Now you know the retraction distance, you can lock that in and then work on the speed. Print another retraction tower to see what speed works best.
5. Record the perfect values: Don’t forget to write down your best values for future prints. They can also help you when changing to another brand or even trying PLA retraction settings instead of ABS.

Conclusion

As we have seen, the ideal settings of retractions are very dependent on the 3D printer used, the type of extruder, filament material, and more specific parameters such as speed and distance. Although the tables above offer a very good starting point, the actual “sweet spot” for your particular machine is obtained through committed testing with retraction towers. By taking ownership of retraction, you can save yourself a great deal of time and filament, not to mention a countless number of headaches, and unlock your 3D printer’s full potential.

What Are 3D Printing Supports?

The basic idea behind 3D printing support types is, as the name suggests, to help support the 3D model. This can be an important step while the model is being printed, as some designs might not be at their maximum strength before they are finished, or they can have overhanging parts, bridges, or complex geometries that need to be kept in place during printing.

In general, 3D print supports are added to the main model itself via the 3D printing slicer, or sometimes baked into the actual 3D model itself, in such a way that it becomes possible to easily remove the supports once the print is complete. The supports can take many different shapes, but all are designed to keep the model from collapsing or creating unwanted results during printing.

Why and When Do We Need 3D Printing Supports?

Why and when supports are necessary will depend on a few different factors. Typically, any sort of overhangs, bridges, islands or deep holes in the 3D model can indicate a need for supports. Since the printer builds one layer at a time, certain geometric shapes are simply not solid or strong enough before more layers have been added, therefore needing the help of extra 3D printed support structures.

Overhangs typically need supports underneath, so there will be no drooping or falling parts during printing. Very short bridges generally can work without supports, but longer ones will need support to avoid them sagging or connecting in weird ways. Islands are shapes that are not connected at the bottom of the print, and often completely isolated from other parts, so they also need a structure to help keep them in place during printing. And finally, deep holes in models can also need support due to similar reasons as overhangs.

The Types of 3D Printing Supports

Now that we’ve discussed the types of problems with some 3D models, it is time to take a closer look at the actual support structures commonly used. Below we’ve included a few image examples to help visualize this.

Tree Supports

We start out with tree supports for 3D printing, as they are one of the most common types for many different models and shapes. They tend to branch out from the base of the printing bed, in order to then slightly connect with any overhangs or other problem areas, to support them in an effective way that also makes them easy to remove. Tree support 3D printing can be quite material efficient compared to some other supports, so that you don’t waste much filament this way.

Grid / Line Supports

Another form of 3D printing support structure is typically referred to as grid supports, although some people call them line supports, as they look like a grid when viewed in 2D. They are great for providing extra strength and stability to a number of different challenging shapes, but are especially used for large and flat shapes, as well as overhanging surfaces that could droop or warp without the support. However, they can be more difficult to remove and they can also use up more filament.

Soluble Supports (PVA, HIPS)

The last method we will discuss today is soluble supports, and as the name suggests, they make it possible to remove the unwanted material in a much cleaner way by dissolving their connection points. PVA is one such material used that can be dissolved with simple water, making it a great 3D filament to use for supports. HIPS is another commonly used material for this method, dissolved with limonene. The downside is that you will need a dual-extrusion printer to use this method, as you need the normal filament in one extruder and the soluble filament in the other.

How to Set 3D Printing Supports

Now that you know a little more about what supports are, and when they are used, it is time to look at how you can implement them. Below, we have described some 3D print support settings you can try out for reference, but remember that they can vary depending on the slicing software and materials, so use them flexibly as needed. We used Bambu Studio and Geeetech PLA filament as our reference point.

Support Placement

We recommend that you choose the option to print supports “On build plate only”, as it will help prevent the support from falling off or becoming unstable. Adjustments may be needed depending on the model however, so keep an eye out at the start of printing.

Support Density

Choosing the density of support structures is an act of balance. The denser the support is, the stronger and more stable it will be. However, it will also be more difficult to remove from your 3D printed designs, and also use up more filament. We recommend starting with around 30% as that is the default. 20% can also work in many cases, so this is the area to adjust from.

Support Z Distance

Choosing the Top Z distance is another factor that plays into your overall support structure, as a larger Z distance makes supports easier to remove but leaves a rougher surface. Start with the default distance and fine-tune for your model.

Support Top Distance

Smaller top interface spacing improves surface quality but makes removal harder. We recommend that you use 0 mm for large interfaces, and then try 0.5 mm for smaller interfaces. Again, this might need some adjustment to get perfect.

Support Overhang Angle

Choosing the angle for support overhangs is another tricky thing. On the one hand, smaller angles generate more supports, while larger angles reduce supports. However, the best setting finds a balance in order to make removal easy.

The default setting is 40° and we recommend to adjust based on your results, so if if the model bottom sags or strings, you should decrease the angle. And if you find that too many supports form, it can be effective to increase the angle.

Support/Object XY Distance

As for the XY distance for supports and objects, the default setting is 0.5 mm, which generally speaking is a good balance.

Soluble Support Settings

Soluble supports can be set very small or even completely tuned down to 0 mm interface distance, but generally, you will want a little distance. If you find that supports fall off easily, then increase density or reduce interface distance.

we also get the option to adjust wall thickness. This is especially important for soluble support structures, as a single layer can have issues with solvent seeping through when you remove the support. In this case, we recommend at least 2-3 layers for a more robust approach.

How to Remove Supports from 3D Prints

The last section for today will briefly cover how you can remove your support structures once they have been printed together with your desired model.

Normal Supports

Before you begin working on your printed design, you should always allow the model to cool down to an appropriate working temperature to avoid any accidents. However, supports are easier to remove when slightly warm, so timing this step right can be helpful as completely cooled off objects are more rigid.

We recommend that you start by removing the supports from the outside in, and also work your way from large to small structures. One technique that many people find useful, is to twist gently or shake up and down. Many times, the supports can simply snap off, but you might need a small tool to help you cut out tough parts.

Soluble Supports

For soluble support structures, the process is different. It will depend on your chosen filament in particular, so remember to read the instructions for your specific material. Below, we have outlined a rough step-by-step guide for both PVA and HIPS, based on our own experience:

PVA:

1. Soak in warm water (30–40°C) for several hours.
2. Stir regularly or use a soft brush to speed up dissolution.
3. Rinse thoroughly with clean water and let dry.

HIPS:

1. Soak in limonene solution and seal the container to prevent evaporation or odor.
2. Dissolution usually completes in 1–6 hours.
3. Remove with pliers, then rinse in fresh limonene to clean residuals.
4. Allow solvent to fully evaporate in a well-ventilated area before handling.

When removing soluble supports, especially HIPS, you should work in a decently ventilated area and wear solvent-resistant gloves and goggles. Avoid skin contact with limonene for optimal safety and wash it off fast if any contact happens.

Conclusion

Hopefully we have helped you understand the key points for the basic principles behind 3D printing supports, different settings and how to remove your structures once completed. For new hobbyists it can take some time getting used to, and dialing in on the perfect settings for your specific printer, and each model can also have slightly different optimal settings.

We’ve also covered how to make supports easier to remove, and touched on the difference between normal and soluble 3D printer support types. So remember, practice makes perfect, and always keep an eye on your printer from time to time, to avoid wasted hours if the support structure or model is not working as intended. Happy printing!

1. Elefantenfuß

Verwendet man das PLA 3D Filament, um Objekte zu drucken, kann es zu einem sogenannten Elefantenfuß kommen. Die erste Schicht des Drucks verformt sich dabei so stark, dass die Schicht kollabiert und „ausbeult“. Diese Ausbeulung ähnelt dann der Form eines Elefantenfußes. Daher stammen auch der Vergleich und die Namensgebung. 

Grund für die Verformung der ersten Schicht ist eine zu hohe Druckbetttemperatur. Diese muss sehr gering sein, denn die Wärmebeständigkeit des Filaments PLA liegt bei 60 °C. Wenn also die Druckbetttemperatur sehr hoch ist, kommt es zu einem Kantenkollaps, der den sogenannten Elefantenfuß verursacht.

Was sollte man also tun?

Begrenze die Heizbetttemperatur, und zwar auf eine Temperatur, die das PLA 3D Druck Filament nicht beeinflusst. Empfohlen wird eine Temperatur zwischen 50°C und 55°C, denn dadurch ist eine gute Haftung garantiert, das Risiko für einen Elefantenfuß beim PLA-Filament jedoch minimiert. Die PLA-Betttemperatur kann also dein 3D Druck Objekt retten!
Auch sollte man den Z-Offset leicht erhöhen, da dies eine Verformung der ersten Schicht minimiert. Ist die Düse zu nah am Druckbett, so kann es passieren, dass das Filament zusammengedrückt wird und „aufquillt“, was auch zu Verformungen und einem Elefantenfuß führen kann. Ein optimaler Abstand ermöglicht eine stabile erste Schicht auf dem Druckbett.

Ein allgemeiner Tipp ist auch, das erste Layer mit einer geringeren Geschwindigkeit zu drucken, denn eine niedrige Geschwindigkeit bedeutet eine höhere Präzision des Drucks!

Speziell bei Slicern wird oft automatisch ein erhöhter Druck bei der ersten Schicht eingestellt, sodass eine bessere Haftung auf dem Druckbett erreicht wird. Dies birgt aber das Risiko für einen Elefantenfuß. Es gibt hier spezielle Einstellungen (Elephant Foot Compensation), bei denen die erste Schicht leicht nach innen gezogen wird, um eine Auswölbung und Verformung des PLA-Filaments vorzubeugen.

Durch das 3D Drucker Einstellen, speziell die Temperaturanpassung der Druckplatte, können 3D Druck Fehler wie der Elefantenfuß mit dem PLA-Filament minimiert und verhindert werden.

Kurz und knapp:
Verformte, ausgebeulte erste Schicht – sieht aus wie ein Elefantenfuß.

• Ursache:
  Zu hohe Druckbetttemperatur (über 60 °C) oder zu geringer Düsenabstand (Z-Offset).
• Lösungsansätze
  • Heizbett auf 50–55 °C begrenzen
  • Z-Offset leicht erhöhen, um Quetschen zu vermeiden
  • Erste Schicht langsamer drucken für mehr Präzision
  • Slicer-Einstellungen prüfen: „Elephant Foot Compensation“ aktivieren

Wir haben bereits detailliertere PLA-Druckeinstellungen vorgestellt – zur Ihrer Orientierung.

2. Feuchtes PLA-Filament

Verwendet man ein feuchtes PLA 3D Filament als 3d drucken material, gibt es einige Herausforderungen, die die Druckqualität und das Endergebnis stark beeinträchtigen können.

Folgende Probleme können auftreten:

(1) Blasen und Knacken beim Drucken

Am Hotend verdampft das Wasser im PLA 3D Filament und es entstehen Miniexplosionen, die als Knacken zu hören sind.

(2) Unregelmäßiger 3D Druck Extrusionsfluss

Durch die Feuchtigkeit im 3D Drucker Filament kann es zu Fäden und Tropfen kommen, da das PLA-Filament nicht regelmäßig ausgeführt werden kann.

(3) Schlechte Layerhaftung

Feuchtigkeit im PLA 3D Filament kann dazu führen, dass die Schichten nicht gut aneinanderhaften.

(4) Beeinträchtigte Oberflächenqualität

Es kann zu rauen und matten Oberflächen kommen, wenn sich Feuchtigkeit im 3D Drucker Filament befindet. Dies beeinträchtigt die 3D Druck Ergebnisse.

(5) Stabilität ist beeinträchtigt

Durch Feuchtigkeit und damit entstehende Blasen und Unreinheiten wird das gedruckte Objekt weniger stabil und neigt dazu, schnell zu brechen oder zu reißen.

(6) Hotend verstopft

Im Hotend können durch die Feuchtigkeit Rückstände und Ablagerungen entstehen. Diese können dazu führen, dass das Hotend verstopft.

Wenn man Probleme beim PLA-Druck hat, sollte man nicht immer davon ausgehen, dass der Grund falsche Druckeinstellungen oder Probleme der Extrusion sind. Warum?
PLA-Filament ist hygroskopisch. Es nimmt langsam und konstant Feuchtigkeit auf. Sprich, die Feuchtigkeit im Filament ist kaum sichtbar. Bei 3D Drucker Filamenten (wie Nylon und TPU) , die stark hygroskopisch sind, kann es zu Blasen oder sichtliche Feuchtigkeit im Filament kommen.

Was sollte man also tun?

Es gibt einige Lösungsansätze, die die oben genannten Herausforderungen umgehen bzw. beheben.

Möchtest du sicher gehen, dass dein Filament keine Feuchtigkeit mehr enthält, solltest du es vor dem Druck trocknen. Du kannst dabei entweder einen Filamenttrockner, einen Ofen mit Umluft oder einen Food-Dehydrator nutzen. Hierbei sollte das 3D Druck Filament 4-6 Stunden bei 45-55°C getrocknet werden.

Auch solltest du das Filament immer in einer luftdichten Verpackung aufbewahren. Zusätzlich solltest du Trockenmittel in deine Filament-Box legen, sodass jegliche Feuchtigkeit von diesen aufgenommen wird.

Es gibt sogenannte Drybox-Setups, die es ermöglichen, das Filament während des Drucks trocken aufzubewahren, sodass auch hier keine Feuchtigkeit aufgenommen werden kann.

Überprüfe regelmäßig, dass dein PLA-Filament trocken gelagert wird, sodass du 3D-Druck-Fehler umgehen kannst und gute 3D Druck-Ergebnisse erzielen kannst.

Kurz und knapp:

Typische Probleme:

• Blasen und Knacken: Verdampfende Feuchtigkeit verursacht Mini-Explosionen im Hotend
• Fäden und Tropfen: Unregelmäßiger Materialfluss durch Feuchtigkeit
• Schlechte Layerhaftung: Schichten verbinden sich nicht sauber
• Raue, matte Oberfläche: Beeinträchtigt Optik und Qualität
• Geringere Stabilität: Blasen im Material machen das Bauteil brüchig
• Verstopftes Hotend: Rückstände durch verdampfendes Wasser

Lösungen:

• Filament vor dem Druck trocknen (4–6 Stunden bei 45–55 °C im Ofen, Filamenttrockner oder Dehydrator)
• Trocken lagern: Luftdichte Boxen mit Trockenmittel verwenden
• Drybox-Setup verwenden: Filament bleibt auch während des Drucks trocken
• Regelmäßig überprüfen, ob das Filament trocken ist

Klicken Sie hier, um mehr über die Lagerung und das Trocknen von Filament zu erfahren.

3. Unsachgemäße Verwendung des Ventilators

Für den PLA-3D-Druck ist es notwendig, einen Ventilator zu nutzen. Und zwar nicht irgendwie; Denn bei einer unsachgemäßen Verwendung kann sich das gedruckte Objekt verziehen, Details gehen verloren und die Struktur verändert sich. Das PLA-Filament verlangt eine kontinuierliche Kühlung, um gute Druckergebnisse zu erzielen.

 
Was sollte man also tun?

Ab der zweiten Schicht solltest du den Ventilator auf 100% einstellen und während des ganzen Drucks anlassen, sodass keine 3D-Druck-Fehler auftreten.

4. Support schwierig zu entfernen

Komplexere 3D-Drucke benötigen eine 3D-Druck-Stützstruktur, denn sonst könnte das Objekt während des Drucks in sich zusammenfallen oder sich verformen. Nach Fertigstellung wird die Support-Struktur vom Hauptobjekt entfernt. Verwendet man das PLA-Filament, kann es dazu führen, dass die Stützstruktur schwer zu entfernen ist und eventuell das Objekt beschädigt wird. Der Grund dafür liegt in der spröden und starren Beschaffenheit bei dem PLA Filament. Bricht man also die Stützstruktur ab, kann es sein, dass auch das gedruckte Objekt an der Verbindungsstelle bricht.

Was sollte man also tun?

Eine Möglichkeit, dieses Problem zu umgehen, ist die Verwendung einer abnehmbaren Stützstruktur-Interface. Das bedeutet, dass die verbindende Schicht zwischen Objekt und Stützstruktur mit anderen Materialien oder besonderen 3D Drucker Einstellungen gedruckt wird (geringere Füllung, geringere Haftung, dünnere Linienführung). Dies ermöglicht, dass die Supportstruktur einfach entfernt werden kann, ohne dass das Druckobjekt beschädigt wird oder unsaubere Oberflächen entstehen.

Eine weitere Möglichkeit ist die Reduzierung der kompletten Stützstrukturdichte, sodass man die Stützstruktur einfach entfernen kann.

Fazit

Vier häufige 3D Druckprobleme mit PLA 3D Filament sind Elefantenfüße, feuchtes 3D Druckerfilament, fehlerhafte Verwendung vom Ventilator und Probleme bei der Entfernung von Stützstrukturen am Objekt.
Es gibt für all diese Probleme Lösungsansätze, die durch Anpassung von Druckeinstellungen, akkurate Verwendung von Ventilatoren und die richtige Lagerung von 3D Druck Filament, die oben genannten 3D Druck Fehler beheben bzw. umgehen können.
Bei der Anwendung der gezeigten Lösungsansätze können 3D-Druckprobleme umgangen werden und tolle 3D-Druckergebnisse erzielt werden.

PETG Stringing

Stringing is a very common problem when printing with 3D printing filament PETG, and is defined as a thin filament that stretches across the gap of the print. Stringing occurs when the molten layer of PETG seeps out of the nozzle while the nozzle moves non-printing directional moves. This can happen for a number of reasons, such as incorrect retraction settings, excessive heat, or the surrounding environment.

Reasons and Solutions

1. High Printing Temperature: PETG filament has good flow at higher temperatures, with the downside of creating excessive oozing.
   Solution: Lower the PETG printing temperature to 220–240°C, depending on your filament brand and printer. Test in 5°C increments to find the sweet spot where extrusion is smooth without stringing.
2. Improper Retraction Settings: Insufficient retraction distance or slow retraction speed fails to pull molten plastic back into the nozzle, causing it to leak during travel.
   Solution: Set retraction distance to 5–8 mm and retraction speed to 40–50 mm/s. Adjust these in small increments in your slicer (e.g., Cura, PrusaSlicer) and test with a stringing test model.
3. Slow Nozzle Travel Speed: If the nozzle moves too slowly over open spaces, molten PETG can ooze, forming strings.
   Solution: Increase travel speed to 100–200 mm/s or higher in non-print areas. Enable “Z Hop” (Lift Z) in your slicer to raise the nozzle slightly (0.2–0.5 mm) during travel, preventing dragging. Note that Z Hop may slightly increase print time.
4. Wet Filament: The moisture absorbed by PETG will become steam during the printing process and lead to increased oozing and stringing.
   Solution: Dry the filament with a filament dryer or in the oven at 60–70°c for 4–6 hours. Store the filament in a sealed container with a desiccant so it doesn’t reabsorb moisture.
5. Poor Nozzle Condition: A nozzle that is worn out, or dirty can cause inconsistent extrusion and leaking.
   Solution: You can clean the nozzle by a wire brush and/or perform a cold pull with cleaning filament. You may want to replace the nozzle if it is worn out or damaged.

The Adhesion Problem of the First Layer

The first layer of any successful PETG 3D printer filament operation is the most important to get right. It is especially important with PETG that you achieve good bed adhesion. If the first layer doesn’t stick to the build plate well, you risk warping and curling as well as the print possibly falling completely off the build plate and destroying the print early on in the process.

Reasons and Solutions

1. Incorrect Nozzle Height (Z-Offset): If the nozzle is too low, the filament may be squished too much or even scraped off the bed. If it’s too high, the filament won’t properly adhere to the print surface and may lead to under-extrusion in the first layer.
   Solution: To fix this, you can just re-level the bed and properly calibrate Z-offset to squish the first layer just so it is forming smooth and gap-free lines. Use a first-layer test print to fine-tune as well.
2. Unsatisfactory Bed Temperature: A cold bed reduces adhesion, while an overly hot one can cause “elephant’s foot” (bulging at the base).
   Solution: Set the PETG bed temperature to 80–90°C, depending on the filament and bed type. Test in 5°C increments to avoid over- or under-adhesion.
3. Dirty Bed: Dust, oils, or leftover filament prevent proper adhesion.
   Solution: Clean the build surface with 70%+ isopropyl alcohol or warm soapy water before every print.
4. Cooling Fan On Too Early: Early cooling causes rapid shrinkage, preventing proper bonding to the bed.
   Solution: Disable the cooling fan for at least the first 2–5 layers to allow the filament to stay optimal temp and stick properly.
5. Unsuitable Printing Environment: Drafts or low ambient temperatures lead to uneven cooling and warping.
   Solution: Use an enclosure or draft shield to maintain a stable environment around 20–25°C.
6. Poor First Layer Contact Area: Small or sharp-edged prints may not grip the bed well enough.
   Solution: Add a skirt to prime the nozzle, a brim (5–10 mm) to increase surface contact, or mouse ears on corners to prevent lifting.
7. Incompatible or Worn Bed Surface: Some surfaces may be too smooth or degraded over time.
   Solution: Apply a thin layer of glue stick, hairspray, or bed adhesive on glass. Replace worn PEI sheets or rough them up slightly with fine sandpaper (e.g., 2000 grit).

Poor Interlayer Adhesion

Interlayer adhesion determines the structural strength of a printed object, and PETG’s potential for strong layer bonding can be undermined by incorrect settings or poor filament handling. When layers fail to fuse properly, parts may split along layer lines under minimal stress. This not only affects functionality but also makes prints more susceptible to mechanical failure.

Reasons and Solutions

1. Low Print Temperature: Insufficient heat prevents proper melting and bonding between layers.
   Solution: Raise the PETG temperature by 5–10°C within the 220–240°C range to improve flow and bonding. Test incrementally to avoid stringing.
2. Excessive Cooling: High fan speeds or early cooling solidify PETG too quickly, reducing layer fusion.
   Solution: Disable the fan for the first 2–5 layers, then use only 10–30% PETG fan speed for overhangs or bridges. Small models may require slightly more cooling (up to 50%) for fine details.
3. Fast Print Speed: Rapid printing limits the time for layers to bond.
   Solution: Set outer wall/perimeter speed to 40–60 mm/s to allow sufficient bonding time. Adjust infill speed to 60–80 mm/s for efficiency without sacrificing quality.
4. Under-Extrusion: Incorrect flow or line width settings result in insufficient filament deposition.
   Solution: Verify E-steps (extruder steps per mm) using a calibration test. Adjust the flow rate in the slicer to 95–98%, or slightly higher (103–105%) if the under-extrusion issue persists.

Nozzle Clogging

For those of us printing with PETG, nozzle clogs or jams can be a very common and frustrating problem. It can cause under-extrusion, skipped layers, and even complete print failure. PETG is a fairly sticky material in its molten state and can adhere to the nozzle when it’s printing at temp, therefore, when the filament begins to cool in the cooler area of the nozzle, it can lead to partial or total stops.

Reasons and Solutions

1. High Print Temperature: Excessive heat causes the filament to carbonize with an incorrect PETG nozzle temp.
   Solution: Reduce the print temperature to 220–240°C to minimize carbonization.
2. Low Z-Offset: The nozzle dragging on the print creates backpressure, leading to clogs.
   Solution: Ensure the nozzle is at the correct height to avoid dragging on the print. Use a first layer test to confirm.
3. Filament Residue: Molten PETG sticks to the nozzle and burns, forming blockages.
   Solution: Inspect the nozzle before and after prints. Clean with a wire brush while hot or perform a cold pull to remove residue. Replace the nozzle if clogs persist.

Rough Surface

A rough or inconsistent surface finish not only looks bad, it can also signal more problems with extrusion or not the best filament quality. Blobs, zits, or stringy textures on outer layers can mainly be contributed to over-extrusion, wet filament or a variable temperature.

Reasons and Solutions

1. Over-Extrusion: Too much filament flow or the nozzle being too close to the bed creates blobs, zits, or uneven layers.
   Solution: Make sure your extruder is calibrated by verifying E-steps and setting the slicer flow rate between 95-98%. Print a single wall cube to make sure this is accurate.
2. Low Z-Offset: An overly low nozzle height causes filament to be excessively squished, leading to bulging layers and artifacts.
   Solution: Raise the Z-offset slightly to allow the nozzle to lay down smooth, even lines without excess pressure.
3. Wet Filament: PETG filament can sometimes absorb some moisture from the air that can lead to bubbles, uneven flow, and defects in the surfaces or contours of prints.
   Solution: Try drying PETG in the oven or using a filament dryer to remove the moisture. Also store your filament in an airtight container with silica gel when not in use.

Conclusion

When troubleshooting PETG printing, you must come up with a systematic methodology. There are issues you may want to consider: stringing, adhesion and interlayer bonding, clogs, and rough surfaces. These issues will require several adjustments to temperature, retraction, cooling, and bed prep. With proper adjustment and testing, your PETG prints will print consistently and with excellent quality.

What Is 3D Printing Post Processing?

Most people who have printed their own objects will most likely have noticed that there can sometimes be small artefacts or lines in the final design that might not be desired. Post processing is any work done after the print is finished, where people enhance the overall look or feel.

Comparison of PLA and PETG Material Properties from a Post-Processing Perspective

In order to get a quick overview, the table below will let you know the main properties for PLA and PETG, so that you can easily determine the best approach for each design.

Surface Processing

Once the print has been removed from the 3D printer, it is time to consider whether to work on the surface. Some designs will look much better after some 3D print post processing, and this is especially useful for gifts or detailed objects where the extra work this entails will produce higher quality designs. There are a few different methods to consider, depending on the filament type.

Support Removal

If you are printing with supports, removing these can sometimes leave excess material. Typically, PLA 3D filament allows you to snap the supports off more easily. PETG filament often requires tools such as cutters or pliers, which can leave small tears or cuts. Due to PETG’s strong support adhesion and high toughness, removing support structures is more challenging compared to PLA. Before removing the support, it is recommended to slightly heat the PETG component, which can reduce the difficulty of removal.

Sanding

Many people use sanding as their preferred method for post processing PLA materials, as this can smooth out the different lines between layers and remove any imperfections. While this method can also work for suitable PETG sanding filaments, it will typically require more work and cleaning the sandpaper more often due to its higher stickiness and heat sensitivity.

Finishing

In order to get the best-looking models, 3D print finishing is often the next step in the post processing routine, which can include priming, painting or even using chemicals to smooth the print further. In this case, PLA 3D printer models can be painted on directly without issue. PETG, however, can be trickier, often requiring an adhesion promoter so that the paint will stick better to the surface and not peel off.

Chemical smoothing for PLA or smoothing PETG with acetone is typically not recommended for beginners, as it is less effective on these materials and can also be hazardous. However, it is still an option to be aware of.

Sand Blasting

Sand blasting is an alternative to sanding where the 3D print is sprayed with fine sand, glass beads or other materials in order to smooth the surface and create a uniform texture. This method requires a careful approach as both PLA and PETG are quite soft and sensitive, and thus can easily be damaged.

Gluing and Assembly

Some prints are either too complex or large to be printed in a single piece. Therefore, we often need to glue or assemble our 3D printed models once they are done. For both PLA and PETG, Gluing and Assembly are fairly easy, however, a few things should be considered.

CA Glue

CA glue acts quite fast and is best suited for bonding small and precise objects. It dries quickly and results in a quite strong bond, however, it is not suitable for bearing loads or flexible designs due to the brittle adhesion and chemical composition.

It bonds better on PLA models than on PETG, but can also work well on PETG, especially if you use sanding techniques to create a slightly rougher surface texture so the glue can adhere properly.

Epoxy

Epoxy is another adhesive material that works well for both PLA and PETG. It provides a strong and durable bond, and is also suitable for load-bearing parts or for bonding larger objects. It can however take up to 24 hours for some types of epoxy to cure.

Epoxy is generally better for PETG as it provides a flexible adhesion that is quite durable. It also works for PLA models with a strong level of adhesion, but in this case, the joint can be slightly brittle because of the properties of PLA material: brittleness and strong rigidity.

Hot-Melt Bonding / 3D Pen Welding

Using a hot glue gun or 3D pen for welding parts together is another method of bonding for PLA and PETG. It is an easy method of keeping your hands and workstation relatively clean and non-messy, however it is important to consider the high temperatures.

For PLA it is generally recommended to use a 3D pen with the same filament that was used for the parts, and possibly a soldering iron for smoothing PLA prints and the resulting seams. PETG can be bonded with either method, and the result will generally be a strong and heat resistant bond.

Painting & Coating

If you wish to further enhance your 3D printed designs, then painting PETG or coating PLA is a great way to add another dimension and more interest. Let us take a look at what this means for both PLA and PETG 3D printer filament.

Painting

Generally it is recommended to first sand or otherwise smooth the surface before painting on either PLA or PETG in order to get the best results. You can get away with not doing as much work on PLA, where both acrylic and enamel paints are great options. For PETG you should avoid paint with strong solvent solutions, and you might even need adhesion promoting materials to help the paint stick.

Priming and Clear Coating

Sometimes fine layer lines can be filled by priming which can be an easy way to make the prints look better without requiring a lot of sanding on 3D prints. Typically, filler primer is used for PLA while PETG can require plastic-specific primers.

Clear coating is a method used for protecting the paint layer, while at the same time also adding a nice shine or matte finish to the print. This is done mostly for models that are of high quality, used for display or handled often.

Functional Enhancement

Taking your 3D printing a step further, you can also choose to enhance your PLA or PETG designs in a few different ways, so that they can better withstand the environment in which you will use them.

Waterproofing

PLA is a filament that naturally absorbs moisture, making it less than ideal for used in wet environments. However, by sealing the prints with epoxy resin or spray-on solutions, you can make the models last longer than normal.

PETG is generally considered to be quite water-resistant due to the chemical composition, but to enhance the properties even further, you can use silicone sealant for any joints or exposed parts that might take damage over time.

Heat Forming

Sometimes you might want to reshape your prints with a heat gun, such as for bending your parts if they require a snap-fit assembly for instance. PLA typically has a tolerance of around 60°C, making it relatively easy to heat form. PETG often requires a bit more heat, some where around 80°C but allows for more precise shaping.

Annealing

This method requires high technical and equipment standards and is commonly used in industrial-grade production, it is another way of heating prints, designed to relieve internal stresses and increase strength. Often, a professional heat chamber or oven is used for this, and generally, not a method used by new 3D print enthusiasts. However, it is still worth knowing about the options out there.

Conclusion

Just because the 3D printed model has left the print bed, it does not always mean it is fully finished. Often we further enhance the look, feel or even properties by processing the prints to achieve the result we are hoping for. There are many different ways and methods for PLA and PETG

Einführung der 3D-Druckerdüse

Die 3D Drucker Düse wird in FDM Drucker und FFF Drucker verwendet. Sie befindet sich am Extruder und ist dafür verantwortlich, das geschmolzene Filament auf das Druckbett aufzutragen. Die 3D Drucker Düse hat eine kleine Öffnung, durch die das Filament in definierter Menge herauskommt. Die Nozzle wird vom Drucker über dem Druckbett hin- und herbewegt, sodass die 3D Drucker Düse das Filament schichtweise aufträgt. Besonders ist, dass eine hochwertige 3D Drucker Düse das Filament präzise und kontrolliert auf das Druckbett aufträgt.

Klassifizierungen der 3D-Druckerdüse

Nicht jede 3D Drucker Düse ist gleich! Es gibt verschiedenes Material und verschiedene Größen, die die Druckart beeinflussen. Hier spielt auch eine Rolle, welches Filament und welche 3D Druck Düsen verwendet, um bestimmte Ergebnisse beim Objekt zu erzielen. Dazu im Folgenden mehr!

Durchmessergrößen

3D Drucker Düsen können in fast jeder Durchmessergröße gekauft werden. Je nachdem, was mit dem 3D Drucker gedruckt wird, ist eine 3D Drucker Nozzle mit einem kleinen Durchmesser oder eine mit einem größeren Durchmesser sinnvoll.
Hier ein kleiner Überblick:

Auf den zwei Fotos sind Objekte zu sehen, die mit einer 3D Drucker Düse mit unterschiedlichen Durchmessern gedruckt wurden.
Das erste Objekt von links wurde mit einem sehr kleinen Düsendurchmesser gedruckt. Das Objekt ganz rechts dagegen mit einem sehr großen Düsendurchmesser.
Hier sind die 3D-Benchy-Druckparameter im Bild (von links nach rechts):

0.15mm Düse: 8h 4m, 11.75g Filament, 0.07mm Schichtstärke

0.25mm Düse: 5h 22m, 12.15g Filament, 0.10mm Schichtstärke

0.4mm Düse: 1h 56m, 12.85g Filament, 0.15mm Schichtstärke

0.6mm Düse: 52m, 13.90g Filament, 0.30mm Schichtstärke

0.8mm Düse: 33m, 15.14g Filament, 0.40mm Schichtstärke

Es ist deutlich zu sehen, dass, wenn Düsen mit sehr kleinem Durchmesser verwendet werden, die Präzision des Endobjekts wesentlich besser ist als die der Objekte, die mit größerem Düsendurchmesser gedruckt wurden.

Materialien

Bei 3D Drucker Düsen gibt es verschiedene Materialvarianten. Die Frage ist, wann macht welches Material Sinn?

Hier die wichtigsten Materialien:

1. Messingdüse:
   Der Klassiker ist Messing, denn Messing hat eine gute Wärmeleitfähigkeit, wodurch das Filament gleichmäßig aufgetragen werden kann. Die relativ günstigen Messingdüsen eignen sich sehr gut für Drucke mittlerer und niedrigerer Temperaturen. Sehr gut können PLA, ABS und PETG gedruckt werden.
   
2. Edelstahl:
   Edelstahl ist weniger wärmeleitfähig als Messing. Dafür ist es sehr robust und abriebfest, was es zu einer sehr langlebigen Option macht. Auch ist es eine gute Wahl für Drucke, bei denen Rostbeständigkeit wichtig ist. Edelstahldüsen werden vor allem für sehr präzise Drucke genutzt und für Drucke mit hohen Drucktemperaturen.
   
3. Gehärteter Stahl:
   Gehärteter Stahl ist sehr abriebfest und langlebig bei abrasiven Materialien wie Carbonfaser, Glasfaser oder metallverstärkten Filamenten.
   
4. Vernickelt:
   Vernickelte Düsen sind Messingdüsen, die eine dicke Schicht von Nickel haben. Verwendet werden vernickelte Düsen beim Standard-3D-Druck, wenn eine höhere Langlebigkeit gewünscht wird. Die Schicht von Nickel ist ein Schutzmantel gegen Korrosion und Abrieb.
   Vernickelte Düsen sind etwas teurer als klassische Messingdüsen, haben aber eine wesentlich längere Lebensdauer.
   
5. Kupfer:
   Kupfer ist der beste Wärmeleiter und empfiehlt sich für Hochpräzisionsdrucke bei hoher Druckgeschwindigkeit. Mit Kupferdüsen erhält man eine perfekte Druckqualität. Nachteil ist, dass Kupfer relativ weich ist und dadurch anfälliger für Abrieb und Korrosion ist.
   
6. Wolframkarbid:
   Wolframkarbid ist sehr abriebfest, langlebig und stabil, was es zu einer perfekten Wahl für Drucke mit Carbon, Keramik und Metallen macht. Die Abnutzung von Wolframkarbid ist sehr gering. Wolframkarbid ist in der Anschaffung teuer, steht aber mit seiner Langlebigkeit deutlich heraus.
   

Wie tauscht man die Düse eines 3D-Druckers aus?

Ist die 3D Drucker Düse deines 3D Druckers beschädigt, hat starken Abrieb erlitten oder druckt einfach nicht mehr präzise, so muss man diese gegen eine neue austauschen. Auch kann es sein, dass du für bestimmte Drucke eine andere 3D Drucker Düse benutzen möchtest und die 3D Drucker Düse wechseln musst.

Hier unsere Kurzanleitung!

1. Erhitze das Hotend

2. Entferne das Filament

3. Halte den Heizblock fest

4. Schraube die alte Düse ab

5. Installiere die neue Düse

6. Abkühlen und testen

Schau dir hier unser Video zum Düsenwechsel an:

Warum verstopft die Düse beim 3D-Druck?

Es gibt viele Gründe, warum eine 3D Drucker Düse verstopft. Hier haben wir typische Szenarien, die Grund für das Verstopfen sein können:

1. Falsche Temperatureinstellungen
Ist die Temperatur zu hoch oder zu niedrig, kann die Düse verstopfen oder eine unregelmäßige Extrusion stattfinden.
Was tun?
->Überprüfe regelmäßig die Temperatur des Hotends. Auch solltest du sicher sein, dass du die empfohlene Temperatur für das entsprechende Filament eingestellt hast. Es kann sinnvoll sein, ein Thermometer am Hotend zu verwenden, falls dein Computer nicht ganz korrekt misst.

2. Verwendung von minderwertigem oder kontaminiertem Filament
Wird Filament falsch aufbewahrt und hat Feuchtigkeit oder Schmutz aufgenommen oder handelt es sich ganz einfach um ein minderwertiges Filament, sollte dies nicht verwendet werden, denn das Risiko ist hoch, dass die Druckqualität sinkt und die Nozzle verstopft.
Was tun?
-> Du solltest einen vertrauenswürdigen Hersteller haben und eine sichere (Luft und Schmutzgeschützt) Aufbewahrung vom Filament garantieren. Bei feuchtem Filament kannst du einen Filamenttrockner verwenden, denn sonst können Blasen und Verstopfungen an der Düse entstehen.

3. Überextrusion oder Unterextrusion
Ist deine Extrusionsrate nicht richtig eingestellt kann die 3D Drucker Düse verstopfen.
Was tun?
-> Kalibriere deinen Extruder regelmäßig und verwende gegebenenfalls ein Kalibriertool, um die optimale Extrusionsrate sicherzustellen.

4. Drucken mit zu hoher Geschwindigkeit
Möchte man sehr schnell drucken, erhöht man das Risiko, dass die 3D Drucker Düse verstopft.
Was tun?
->Reduziere die Druckgeschwindigkeit oder passe andere Druckeinstellungen an, sodass keine Verstopfungen auftreten.

5. Falsche Retraction
Die Rückzugseinstellungen (Retraction) müssen optimal eingestellt werden, da auch hier sonst die Düse verstopfen kann.
Was tun?
-> Optimiere Länge und Geschwindigkeit von Retraction und überprüfe, ob der Rückzug richtig funktioniert.

6. Verwendung der falschen Düse für bestimmte Filamente
Bestimmte Düsen werden für bestimmte 3D Drucker Filamente genutzt. Wird dies nicht berücksichtigt, so können Verstopfungen entstehen.
Was tun?
-> Stelle sicher, dass du die richtige Düse für dein Filament verwendest. Im gegebenen Fall solltest du deine Düse mit einer passenden 3D Drucker Düse austauschen.

7. Unzureichende Kühl- oder Heizeinstellungen
Der Druckfluss kann von falschen Kühl und Heizeinstellungen beeinflusst werden.
Was tun?

-> Eine kontinuierliche Überprüfung deiner Kühl und Heizeinstellungen während des Druckprozesses ist sehr wichtig. Das Hotend sollte eine konstante Temperatur haben. Bei Schwankungen kann es zu Verstopfungen kommen. Achte also darauf, dass der Lüfter des Hotends richtig funktioniert.

8. Alte oder abgenutzte Düse
Ist deine 3D Drucker Düse verstopft, kann das daran liegen, dass die Düse alt oder abgenutzt ist.
Was tun?
-> Tausche deine alte oder abgenutzte Düse gegen eine neue Düse aus

9. Ausgefallener oder schlecht kalibrierter Extruder
Ist der Extruder schlecht kalibriert, so kann es zu Verstopfungen in der Düse kommen.
Was tun?
-> Kalibriere deinen Extruder regelmäßig und überprüfe deinen Extrudermotor auf Fehlfunktionen und Blockaden.

10. Verstopfungen am Hotend (Hitzekriechen)
Das sogenannte Hitzekriechen bezeichnet die Situation, in der das Filament bereits bis zum oberen Ende des Extruders geschmolzen ist.
Was tun?
-> Hotend und Extruder müssen gut isoliert sein, sodass die Wärme das Filament nicht bereits zu früh erhitzt. Stelle sicher, dass der Extruder während des Druckvorgangs nicht überhitzt. Gegebenenfalls solltest du die Isolierung vom Hotend und die Kühlung vom Extruder verbessern.

Fazit

3D Drucker Düsen sind ein essenzieller Bestandteil von 3D Druckern. Es gibt 3D Druck Düsen in verschiedenen Größen und Materialien. Je nach Druckart, Material und gewünschtem Endprodukt muss eine spezielle Düse gewählt werden.
Wenn eine 3D Drucker Düse verstopft, so müssen verschiedene Aspekte des Extruders, Hotends und der verschiedenen Einstellungen berücksichtigt bzw. überprüft werden, sodass man das Verstopfen der Nozzle verhindern kann und hochwertige 3D Drucke machen kann.

1. Why does mixed color printing produce stringing or oozing?

We can go to the Cura official website to report similar slicing problems. Some reasons may not be a problem with the machine. Issues related to stringing: 1. Different manufacturers and types of consumables 2. Slicing setting temperature 3. Slicing retraction length. It may also be the difference between the structure of the mixer cavity of the A30T print head and single-head printing. Please confirm the usage age of the 3d printer. If you want to replace accessories, you can search our Geeetech official website to purchase new accessories.

2. Why do those colors mix on the printing results?

We collected the real experience of fans. One of them shared as follows:

A30T prints fine in pla with 4mm retraction while pla+ always strings no matter what settings are used. If you want it to print better, you can try to replace the Boden tubes with a direct drive extruder. The only reason for these usages and this style extruder is so it can print faster without the extra weight at the hot end. But anytime it slows down in the print movements without extruding filament will keep expanding and will leave blobs or thick strings. So his fix was extra retraction and speed up the whole printer he used 5500.0mm/min and raised the allowed minimum speed reductions to 30% instead of 20% the slicer. He has used every printer he owned Simplify3D through USB.

3. How to correctly print mixed-color or color-separated models？

Here are some solutions that we offer to you.

A. For multi-extrusion printers to print mixed color or gradient models, you can operate in the following three ways:

1. Just slice the monochrome model through the slicing software, and operate the start color mixing ratio, end color mixing ratio, and color mixing height on the printer. This method is simple and direct.

2. Geeetech official provides EasyPrint slicing software, which can meet the user’s color mixing requirements through visual interactive operations. This method is more flexible and interesting.

3. Using Marlin Gcode instructions M163/M164/M166, you can print models with any color mixing requirements. For details, please refer to Marlin’s official website instruction usage format https://marlinfw.org/meta/gcode/. This method requires users to be familiar with the Usage of Marlin code.

B. For multi-extrusion printers printing color separation models, a wiper tower needs to be set up to ensure that the residual filament inside the nozzle is fully extruded onto the wiper tower after the filament is withdrawn. To achieve the best cleaning effect, you can try the size and volume of the wiper tower.

Fortunately, we can refer to 3DSage’s unique method of getting a beautiful look without using sandpaper.He printed a model of the skeleton as a demonstration. All you need is a can of spray paint that combines well with plastic (such as Rust-Oleum) and a bottle of Fast Drying Polyurethane – Clear Satin. Let’s get started!

The first step is to check whether there is dirt or dust on the 3D printed model and make sure there is nothing superfluous on the surface.Apply a spray paint of your choice to the model, followed by a quick coat of polyurethane.

Next, to make the coating dry faster and prevent drips, you should carefully place the model under the fan.At this point you can see that the mixture of paint and polyurethane will blend into the layer, making up for any holes or unexpected imperfections and working best with thin layers and patience.3DSage said he waited for a whole day before adding the final coat of spray paint.And the time interval between layers is 20 minutes in order to prevent discoloration and make up for defects.

When it comes to the benefits of his craft, The Maker says it allows him to print faster with a greater layer thickness.This process will mask any rough and unsightly appearance.And you can choose any color of paint.In this way,you get a smooth print model that doesn’t require polishing or other post-processing techniques.

Without a doubt, you can’t bear some minor flaws in the surface of a 3d printing model, let alone “String”. You complained that this printer is such trash contrary to expectations. At that time, you may get mad but it will eventually end up in a mess. So firstly you need to calm down. Take a close look at what is the exact problem, make it clear how it happened, and how we can solve the problem. Let’s dive in.

What’s the Problem?

3D Printing Stringing exists when small plastic strings are left behind on a 3D-printed model. This is usually due to plastic leaking from the nozzle as the extruder moves to a new position.

How to fix this？

In this article, we bring 5 solutions that can be commonly used on all the major 3D printers.

1. Enable Retraction

Enabling retraction is the most ordinary way to fight against 3D printer stringing. Enabling retraction means that when the extruder has to pass through a gap, the filament is retracted a little bit by the feeder. Once the extruder reaches the next position, the filament is pushed out and the print continues again from the nozzle. If the retraction setting is turned on and you’re still experiencing 3D printer stringing, you may then need to go into the details of the retraction settings:

• Retraction distance

The most important retraction setting is the retraction distance. This determines how much plastic is pulled out of the nozzle. Generally speaking, the more plastic that is retracted from the nozzle, the less likely the nozzle is to seep out as it moves. Most direct-drive extruders only require a retraction distance of 0.5-2.0mm. If you run into stringing with your prints, try increasing the retraction distance by 1mm and test again to see if the performance improves.

• Retraction speed

The next retraction setting that you should check is the retraction speed. This determines how fast the filament is retracted from the nozzle. If the retraction is too slow, the plastic will slowly leak out of the nozzle and may begin to leak before the extruder moves to its new position. If you retract too quickly, the filament may separate from the hot plastic inside the nozzle, or the rapid movement of the drive gear may even grind away pieces of your filament. There is usually an optimal retraction point between 1200-6000 mm/min (20-100 mm/s).

If standard retraction isn’t doing the trick, you can try to reduce the minimum travel. This is usually the quickest solution to fix stringing issues. Drop the value by 0.5mm until the stringing has stopped completely.

2. Set the Right Temperature

The 3d printer extruder temperature is the next most common cause for stringing. If the temperature is too high, the plastic inside the nozzle will become less sticky and more likely to leak out. However, if the temperature is too low, the plastic will be one kind of solid and difficult to extrude from the nozzle. If you thought you had the right retraction settings but still have these problems, you can try to decrease your extruder temperature by 5-10 degrees. This will greatly improve the quality of your printing.

3. Movement Speed

Moreover, increasing the movement speed of your machine can also reduce the time it takes for the extruder to leak as it moves between parts. The X/Y Axis Movement Speed represents the side-to-side travel speed and is frequently directly related to the range of time your extruder spends moving over open air. As long as your machine can move at higher speeds, increasing this setting may reduce stringing between parts.

4. Thoroughly Clean the Nozzle Before Printing

When you use a printer for a long time, the filament can leave a thin residue layer in 3d printer nozzle. This thin layer can cause 3D printer stringing as filament strands will try to stick to the surface of your printed part. To avoid such a problem, ensure your nozzle is thoroughly cleaned before print.

5. Keep Your Filaments Moisture-Free

PLA, which absorbs more water than ABS, is the main culprit. The water turns to steam when the plastic is heated up, and it can mix with the plastic to increase the likelihood that it will seep out during non-printing movements.

Therefore, it is very important to store the filament properly, especially if you live in a humid environment. For more guidance, check out the previous blog here：How to store filament? 

You must be disappointed when seeing blobs marring our 3D prints.,which is commonly called“zits” ,can occur due to the frequent start and stop of extruder as it moves around.These blobs on your model represent the position where the extruder began to print a part of the outer shell and then returned to the same position after printing the perimeter.Without leaving a mark, it’s hard to connect two pieces of plastic , but here we figure out two tips to keep the blobs from occuring on the surface of your print.

Tip 1:add a negative extra restart distance

Finding out where they are occurring is vital to reduce blobs.You should make sure if blobs happen at the beginning of the perimeter,or as the perimeter finishes printing.If it is the former, the extruder is most likely priming too much plastic.To solve this problem,you can attempt to adjust your retraction settings,add a negative extra restart distance. For example, if your retraction distance is 2.0mm, the extra restart distance decreases by 0.4mm, and each time the extruder stops, the filament will be retracted 2.0mm .But when it starts again, 1.6mm of the filament will be pushed back into the nozzle.You ought to keep tweaking this number until there are no blobs.

Tip 2:turn the “coasting” setting off 

If you find that the blob is happening as the extruder finishes printing a perimeter,it is posssible that the built-up pressure inside the extruder nozzle pushes out more plastic than expected. In this instance, the best solution is to turn off a setting called “coasting” just before the end of the perimeter ,which can relief some of the built-up pressure within the extruder.Try turning this feature on and increasing the value until the blobs stop appearing.

So that’s the solution to the blobs. Now I am printing a larger Pokemon toy.I can’t go wrong this time, for the sake of my beloved girl.

Source:　https://www.simplify3d.com/preventing-blobs-on-3d-print/