The Perfect Prusa i3 PETG Settings

PETG stands for polyethylene terephthalate glycol-modified. The presence of glycol makes the material less brittle, much easier to print, and more transparent (compared to the parent material, PET). PETG is arguably the second most common printing material that is 3D printed today.  It seems to be the next step in the natural progression for most people in their 3D printing journey(with regards to 3D printing filament).

PETG is a great material with a lot of unique properties that make it perfect for functional application. It is used in different industries for a variety of things ranging from toys to plastic bottles and even Prusa Research uses PETG for most of their printer parts. This printing filament is also fully recyclable.

This article is centered on providing information about the perfect Prusa i3 setting for printing with PETG. In addition to this, we will also provide tips on how to make successful 3D PETG prints. We will also get to know more about PETG by talking about its pros and cons and its application.

Before we talk about any of those, let’s quickly take a look at the properties and required printing conditions of PETG. Some of these properties set the standard for the right setting and it is quite important that you have the knowledge.

Properties of PETG

The properties of PETG are listed below;

Properties and printing conditions of PETG                                           

1. Flexibility: Medium
2. Warping: Minimal
3. Durability: High
4. Strength: High
5. Solubility: No
6. Softening temperature: 85 °C
7. Printing temperature range: 230 - 250  °C
8. Bed temperature: 60 - 80 °C
9. Printing speed: 40-60mm/s

In addition to the properties above, PETG has great chemical and impact resistance, ductility, and transparency. These properties are the grounds on which the right settings are made. We’ll see the relationship as we go on.

Best Prusa i3 PETG Setting

Prusa i3 printers are quite efficient in the 3D printing world. These printers come with features that make it perfect for printing a range of printing filaments including PETG. For example, the maximum nozzle temperature of Prusa i3 MK3S+ is 300 °C which is higher than the required print temperature for PETG filament( as seen above). 

Although the printer already has features that support the printing of PETG, you will have to set the machine right to get impeccable results. These settings are usually done in the slicer. A slicer informs the printer of everything it needs to know to create an item efficiently. Prusaslicer is a common open-source software used for this purpose in Prusa printers. If you don't have the software installed, you can download it onto your Mac, Linux, or Windows device from Prusa’s website.

The perfect PrusaSlicer setting for PETG printing with Prusa i3 is given below:

• Nozzle temperature: For extrusion-based 3D printing, the nozzle temperature of the printer needs to be sufficient to allow for proper extrusion of the intended filament. The Prusa i3 has a maximum nozzle temperature of  300 °C  which is quite convenient for PETG. However, for best results on the Prusa printer, set the temperature to 230 °C for the first layer and 240 °C for subsequent layers.
• Bed temperature: Bed temperature influences how well a print sticks to the build platform. The Prusa i3 has a  magnetic heatbed with removable PEI spring steel sheets with a maximum temperature of 120 °C. However, for the best chances of success in printing with PETG, it is recommended that the heatbed is heated to about 85  °C for the first layer, and 90  °C for subsequent layers.
• Layer height: The Z-axis advances up every layer by the layer height. Smaller layer heights produce more detailed prints, and bigger layer heights produce stronger parts. While still divisible by 0.04 mm, a layer height of 0.2 mm provides a decent balance of strength and detail. We recommend using a 0.16-mm layer height if you want more intricate pieces. Use a 0.24-mm layer height if you want to make pieces that are even stronger.
• Printing speed: Because speed is such an important slicer setting, it may greatly affect your prints. Print speed refers to how quickly your printhead moves while printing. Printing too quickly can result in under-extrusion and messy prints while printing too slowly might cause the hot end to clog, a process known as heat creep. The Prusa i3 MK3S+ has a top speed of 200 mm/s. However, for PETG printing, a speed of 40 to 60mm/s is recommended. Although it is advisable you maintain a speed of 20mm/s for the first layer.

Travel speed is another important slicer variable that influences how quickly your printer moves when it is not printing. A travel speed of 130mm/s is recommended.

• Infill: The density of the part is affected by the infill settings, which has a direct impact on the print's strength as well as the time it takes to print. Print time is frequently increased with more strong infill settings, while print time is reduced with weaker ones. The infill percentage, as well as the infill pattern, are the most important infill settings. The density of a part's infill is determined by the infill percentage. As a result, a 100% infill is totally solid, whereas a 0% infill is hollow.

Consider utilizing a 40-60% infill percentage if you would like to create functioning parts. If cost is a problem but strength and functionality aren't, a lower percentage of roughly 10% might suffice.

• Retraction: To avoid stringing and other difficulties, 3D printing parts require retraction. Retraction is the process of pulling the filament back when the printhead isn't printing to prevent the extra filament from seeping out of the hot end. PETG has a tendency to ooze and may leave plastic strings on your print. You can combat this by increasing retraction and adjusting the nozzle temperature. But if you use Prusa's filament defaults in PrusaSlicer for PrusaControl, this has already been done for you, and stringing is minimal. If you do see a smidgeon of stringing, you may rapidly remove it by blasting your finished prints with a heat gun. Typically recommended retraction for PETG though is 5mm at 40mm/s.

• Brim width: The brim width is essential for print bed adhesion. The broader the brim, the better your object sticks to the print bed. The width of the brim can be adjusted in PrusaSlicer. A 5mm brim width is recommended for PETG.

Summary of Prusa i3 settings

• Nozzle temperature- 230°C for the first layer, 240°C for other layers
• Bed temperature- 85 °C for the first layer, 90°C for others.
• Layer height- 0.2mm
• Printing speed- 40 to 60 mm/s
• Retraction speed- 5mm at 40mm/s
• Brim width- 5 mm
• Infill- 40-60% for functional part, otherwise 10%
• Traveling speed- 130mm/s

With this setting, you can expect a near-seamless print. For perfection, we have compiled some tips that can help you get your desired prints.

Tips for A Successful  Print

• Clean the print surface

Before printing, ensure you clean the print surface to get the best adhesion. Cleaning can be done with a window cleaner. Use an unscented paper towel soaked with a small amount of the window cleaner to wipe the print surface. In the absence of a window cleaner, warm water with some drops of dish soap can be effective as well. Ensure you clean the bed while it's at room temperature. At a higher temperature, the cleaning liquid might evaporate before doing any cleaning.

• Use cooling fans

You might consider utilizing a cooling fan when printing with PETG. The rapid cooling aids in keeping the print detailed and free of blobs as well as stringing. Although, it is advisable to print without a fan if you want the strongest print possible because the higher filament temperature will help the layers stick together even better. If you must use a cooling fan,  print the first few layers without the cooling fan and then turn the fan on half power for other layers to avoid warping.

• Storage

Some PETGs are hygroscopic in nature. This means that they absorb moisture from the environment. Therefore, you should store it in a cool dry place. Moisture deteriorates the filament and this may not produce the best print results.

Now it's time to learn a little bit more about PETG. The pros and cons, and its application.

PETG: Pros and Cons

Pros

• High-temperature resistance
• Low warping
• Easy to use
• Tough and durable
• Smooth surface finish
• Glossy
• Less brittle
• Good layer to layer adhesion
• Recyclable

Cons

• Prone to stringing
• Poor bridging characteristics and overhangs
• Strong adhesion to the bed, making it difficult to remove the prints
• More prone to scratches (compared to PLA)

Application of PETG

• PETG is a very strong and durable material, hence it can be used in the production of functional mechanical parts, like parts of the Prusa printer.
• PETG is also ideal for making holders or clamps.
• PETG is useful for waterproof applications due to the strong layer adhesion of the printed materials.

Conclusion

Polyethylene terephthalate glycol-modified, also known as PETG, is a very good 3D printing material. Its properties make it suitable for a broad range of applications. To make successful prints with PETG, you'll need to have the right settings on your printer.

The Prusa i3 printer is ideal for printing PETG materials because it meets all of the standard printing conditions of PETG filaments and also has a default setting to help minimize stringing. The perfect setting required for printing PETG on Prusa i3 was covered in this article, as well as some tips for successful printing. You should have really good prints when you follow this guide.