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/

Whereas 3D printers using the same technology and marketed for about the same price usually do not vary much(theoretically) in terms of print quality, the results of post-processing can vary greatly depending on your expertise and skills. Simply put, you take either 100 percent blame or credit for your finished 3D prints.

So, what processes are involved in post-processing?

•Cleaning

In FDM, cleaning usually means to remove support structures from the object.

As we know, there are two types of support material: soluble and insoluble. Insoluble material is relatively strong and can only be removed with a spatula,knife or sheer brute force,leaving the model and print platform vulnerable from possible damage.

If you are lucky enough to own a dual extrusion setup, you may want to use soluble material for your supports. Soluble materials such as HIPS and PVA, can be dissolved in water or Limonene.

Check out our previous blog on how set up your 2 extruder 3D printer.

•Fixing

One way to circumvent supports is to have your model printed separately. This means you will have to manually attach together your parts. ABS prints can be welded or glued together using acetone. Here is a tip you should heed: when creating joints or keys for a model, make sure to create joining features large enough for the 3D printer to create them cleanly. Thumb of rule is that features should be larger than 4-5mm in diameter. Glued components should be secured together using rubber bands, and cyanoacrylate glue should be used to spot glue around the connecting areas. If seams are rough or have gaps, bondo or filler can be used to smoothen them.

•Surface finishing

Sanding

Layer lines are the bane of models printed using FDM technology. Carefully sanding the surface of the model with paper should get rid of the lines. This process requires delicate skills and great attention. Start with higher grit to lower as you go. Do not sand in one place for too long as friction-generated heat could melt the material. The downside to manual sanding is inconsistent results, as well as being laborious.

Smoothing

To give the print a glossy finish, chemicals are sometimes used. For example, Acetone and THF are used to smoothen the surfaces of objects printed with PLA and ABS. The problem with this technique is that it can not be controlled: sometimes features are melted off that should remain. On top of that, vapours can be harmful when inhaled.This can be avoided using closed chemical cleaning machines.

•Coloring

Coating and Painting

Surface finishing is often followed by painting. Parts need colouring would ideally be printed using white material. A layer of primer is usually applied before the model is painted,followed by another stage of sanding. Painting is usually done manually using a brush or spray(at an arms length). It is highly recommended that you hang the object in an open, dust-free,well ventilated space. This will allow you to paint all surfaces evenly without having to handle the model while paint is drying. The painted object should be ready to polish after 1-2 days.

Credit: beamler, 3der

Before reading this article, please make sure you have already read the setup guide of the version of the 13B single extruder and that you are able to use it to print 3D models. If not, please learn how to operate the single extruder. Of course, you can take this one as the single extruder version to get started.

Step 1

Open Repetier Host, and click Config/Printer Settings to set up the connection.

1. Name your printer.

2. Select the corresponding COM port and baud rate. The baud rate is generally 115200 or 250000.

3. If you are not sure about the COM port, you can check it in your device manager.

Step 2

Set up your extruder

1. Choose the number of extruders, here we choose
2. Select the diameter and color of the filament
3. Offset X/Y refers to the distance between the two extruders, which can be adjusted based on real situations. You can leave it alone now.

Step 3

Set up the shape of the printer

Choose Classic printer as the printer type.

Home X: min Home Y: min Home Z: min

Print height: 150

Now you can click the Connection button on the left corner to check whether it can connect with your printer. If it fails, please recheck the COM port and Baud rate.

Step 4

Manual control

1. X home

Click X home to home the X axis, or you can click the right/left arrow to move the axis to check whether the direction and distance are correct or not；

2. Check Y axis and Z axis respectively in the same way

3. Click the icon of the heated bed on RH to heat the bed. observe whether the temperature is rising to a pre-set value

4. Click the icon of the heated bed and extruder, observe whether it is heating up to the pre-set temperature, and keep it at that value

5. When the temperature for the extruder surpasses 170 °C , choose extruder1 and extruder2 respectively, you can move them and check their directions

Step 5

Leveling the two extruders.

Leveling the two extruders is very important if you want to print with two extruders at the same time.

First, you can adjust one extruder to make it parallel with the surface of the heated bed (the same way you level for a single extruder setup), click the button of Z home to adjust the distance between the nozzle and the heated bed, make sure the vertical distances of the nozzle to the four corners of the bed are the same.

After that, tweak the distance between the second extruder and the heated bed by adjusting the screws, as shown in the following picture: Loose the screws, and then you can move on to get the right distance between the two extruders and the heated bed.

you may need to repeat this step to get it all right.

But it’s worth it. Once you get it done correctly, you won’t need to do it again.

The settings mentioned above are on Repetier Host, which only involves the control of the 3D printer and the preview of the model.

All the settings do not concern the print result but the slicing. So we will continue with the slicing setting. The slicer is independent of Repetier Host. So, should we set up the slicer now? Take it easy. Let’s see whether our printer can run normally.

Step 6

If the printer goes well. We can go on with the slicing. First, let’s get a quick view of the slicer.

RepetierHost supports many slicers, with Slic3r and CuraEngine being the most popular; Slic3r is more powerful in terms of functionality, but CuraEngine comes with more optimized slice velocity.

You can choose a slicer here. Upon selecting the slicer, please click Configuration.RepetierHost will bring up a wizard of the corresponding slicer that will walk you through the configuration.

Here we take Slic3r as a demonstration. As to the configuration in CuraEngine, we will pick it up in the follow-up study in our forum www.geeetech.com/forum/, so, please stay tuned. If you are experienced in CuraEngine, we would appreciate it if you could.ld share your insights with us.

Next, download the file:two_color_cube.zip, unzip the file, and save it somewhere. You will need it later.

Step 7

Click Configuration， open Slic3r

Step 8

We have prepared a set of parameters for I3B_2E dual extruder, that is, I3B_2E_config_bundle.ini. You will need to import those parameters to slic3r from here.

In Slic3r, under file> Load Config Bundle.. navigate to the folder we just downloaded and unzipped, open I3B_2E_config_bundle.ini,

Step 9

After loading, you can find the option of Geeetech_I3B_2E in the drop-down menu.

In my case, I use the Geeetech pro-C model,(I refer to the I3B_2E in this article)， the extruder is MK8(1.75cm-0.4mm)， PLA filament, so we choose Geee_I3B_2E, PLA 1.75mm, and Geeetech_I3B_2E respectively.

All the parameters you set can be saved in RepetierHost for future reference.

Step 10

Unzip two_color_cube.zip， click Load to import the .stl files，choose two_color_cube_1.stl and two_color_cube_2.stl respectively.

Actually, two_color_cube is composed of two .stl files. each printed by one nozzle.

After loading, you can preview it. The two files are separated. Now you need to adjust the locations to combine them together.

Select Object Group 2 and click center, then Object Group 1 and center. Now the two models are combined as one.

Assign printing tasks for both extruders respectively.

Step 11: Slice

If this warning pops up, choose NO

G-code is generated successfully

Step 12: you can print directly via serial port (USB connector）or save the G-code to an SD card, and print stand-alone.

Step 13′: The end

This post was originally published on the Geeetech wiki page and is edited in this blog.

Please be noted this article was last modified on 11 August 2015, and hence is subject to changes, due to software updates and hardware upgrades over the years.

If you already have a dual extrusion system, we would like to hear from you. Share your story/experience with us by joining our forum or Facebook user club. You are also welcome to write on our blog to reach a larger audience.

Assembly & Set Up

Set up your 3D printer as per the instructions. No matter how experienced you are, your vendor supposedly knows the products better than you do. It is recommended that you use parts, software, and materials from the same brand wherever you can to get the best experience. Remember, every 3D printer has its characteristics. Be open to some trial and error down the road.  

Software Update

Keep your system up to date. Manufacturers and slicer companies are constantly experimenting with their software and firmware to fix bugs and improve performance. If your machine features an automatic update, enable it.

Maintenance

Perform regular maintenance and calibration on your 3D printer: Form and maintain a routine of checks; keep your filaments from moisture and dust; calibrate the bed.

Supports

Bear in mind the 45-degree rule and 5mm rule. Any overhangs of above 45 degrees(or 60 degrees depending on your printer) may require supports. Just like overhangs, not all bridges require support. Consider supports only when the bridge is more than 5mm long. “Rafts”, and “brims” are great support tools to increase adhesion. Add support structures to your design for any steep overhanging features or models that have a small base.

While supports are great for some cases, you may want to avoid them, for the following reasons: first, they consume extra filament; second, the print takes longer time; and finally, removing the support structure of the print can be a pain. If you are still not sure whether you need support, run a test print to find out. You can also use your creativity to make the support structures part of your design, in case you think them necessary. Ways to circumvent supports: reorient your model; reduce the overhang angles; and split your model into smaller parts.

The first layer

Your first layer is the foremost important layer of your print. Make sure it sticks well to the bed. Again, support structures, a heated bed, and glue all are great tools to help with adhesion.

Details

Examine the details of your model. Are there any tiny projections or parts that are too small to print on a desktop 3D printer? In your printer, there is a very important but often overlooked variable, that is the line width, which is determined by the diameter of the printer nozzle. Most printers come with a nozzle of 0.4 mm or 0.5 mm in diameter.

3D printing stringing can be a common problem especially if you are a newbie or when dealing with a new machine or material. But luckily, it is a problem that is fairly easy to solve. Let’s look at some causes and the corresponding solutions:

Retraction distance

Retraction distance is the most important retraction setting as it determines how much consumables is pulled back from the 3D printer nozzle. Generally speaking, the further your nozzle retracts, the less likely oozing is to happen. But if the distance is set too high, the plastic may not be able to to reach the hot end and may cause under extrusion. In general, Bowden extruders require a higher retraction distance than direct drive extruders.The optimal value falls in somewhere between 4-7mm(most likely to be 6mm) for most Bowden extruders and 0.5-2.0mm for most direct drive extruders. Some trial and error is probably going to be required to get the retraction distance right.

Retraction speed.

Retraction speed determines how fast the material is retracted from the nozzle. Generally, a quicker retraction will reduce the chances of leaking. But again, it could also be problematic: first, it may cause the plastic to separate from the melted filament inside the nozzle; second, the fast movement of the drive gear could grind parts of your filament away. A sweet spot is usually found somewhere between 25-40mm/s. Again, you will need to experiment to get the optimal value.

Temperature

If stringing persists after you have tweaked around the retraction settings, go on to check the extruder temperature. As the temperature goes up, the plastic inside the nozzle becomes more liquefied and less viscous, and therefore, more likely to drip out of the nozzle. On the other hand, if the temperature is too low, the filament may not be properly heated and melted,creating problems with extrusion. To fix excessive stringing and avoid issues with extrusion, start out by lowering the temperature by 5-10 degrees to see if the print quality improves.

Temperature setting for filaments:

• PLA 185°C – 215°C, hot bed 25°C – 60°C
• Silk PLA  200-230°C, hot bed 40-60°C
• ABS 230-240°C, hot bed 100-110°C
• PETG 220-240°C, hot bed 80-90°C
• TPU 200-230℃, hot bed 50-60℃

Travel distance and speed

Another possible solution to stringing is to reduce the distance between points/locations the extruder travels. As we already know, stringing occurs while the extruder is moving to the next point. Therefore, the reduced travel distance will slash the chances of leaking. By the same token, increasing the movement speed of the extruder can also prevent stringing from happening.

Maintenance

To avoid stringing, you are also suggested to do the following :

1. clean your nozzle. Necessary tools for cleaning nozzle: tweezers, wrench, cleaner rod, needle and allen key. Firstly you need to preheat nozzle and use tweezers to remove extra filament from nozzle. Then you need to unload the filament and pull out the PTFE tube from hotend. Next, use a cleaner rod to push in and out nozzle for several times to clean it thoroughly with proper strength.

2. keep your filament clean and dry. We recommend you to use vacuum bag or dryer box to stock your filaments. If you keep it expose to some extent humid air and dust for a long time then it will certainly affect heating process and more likely to break during printing process.

Reminder: performing a routine maintenance on your 3D printer always helps with your print quality.