There’s a lot of information to gather when it comes to 3D printing and it’s easy to get lost in it. So neglecting the first layer settings isn’t unusual, especially if you’re a beginner. But the first layer result is important for the successful print of the entire model and sometimes all we need is just a single-layer print.
Now, the question is: how do we get that perfect first layer in Cura? In Cura, there are setups that you can customize to modify the line width and the first layer height. These options are found in the Cura first layer settings, which are part of the “Advanced” tab found in the “Quality” section. You’ll also find the section called “Preliminary Layer Density”.
It’s crucial for you to understand how to set up the first layer together with all the other settings that are connected to it. Fortunately, when you focus on one element at a time, the entire process becomes straightforward. So let’s start exploring these settings and learn how to get a perfect first layer in Cura.
The First Layer Setup
The first step is to check whether the printing bed is perfectly leveled. Before you start printing, you should consult your printer’s manual and follow the instructions to level the surface area. Otherwise, your print will be unsuccessful no matter what you do.
Next, once the platform is level, the next step is to adjust the first layer settings. The purpose of the first layer is to bind the model to the printing area. For example, if the nozzle is too far away from the printing bed, the filament will just sit on the platform due to lack of compression.
What you need to do is make sure the first layer is 90% less than the rest of the layers. In other words, the same amount of material is going to be applied in an area that’s 10% lower than the other layers. For example, if the layer height is 0.3 mm the first layer elevation will be 0,27 mm, if the height is 0.2, then the elevation is going to be 0.18, and so on.
The line width represents the size of the first layer’s lines and it has to be close to the size of the nozzle depending on the height of the layer. By decreasing the outer wall’s line size we will get more details to the model, and by increasing the infill’s line size we’ll speed up the printing process.
Getting your first layer to stick
Adjusting the height of the nozzle will certainly help the first layer to stick, but you can do more. You can use additional materials on the printing plate to ensure a better grip. Just don’t forget to also clean and maintain the plate. With that in mind, here’s what you can apply:
- Glue: Using a simple glue-stick that can be cleaned afterward with hot water will help with adherence.
- Hair spray: This helps with glass build plates, but wait for it to fully dry first.
- Painter’s tape: This gives PLA material a better grip.
- Kapton tape: This tape is best used when working with ABS filament.
- 3D printing glue: Using specialized glue is ideal in most cases.
Optionally, you can use adhesion types, namely a brim, raft, or skirt. The use of each one depends on the model’s design.
The brim is a one-layer section around the base of the model. Its purpose is to prevent the design from bending upwards or warping. By using a brim, we create a larger surface for the model and that can vastly improve the adhesion to the plate. Usually, you’re going to use this adhesion type when printing models that are likely to contract.
To use a brim you’ll have to adjust the brim settings, namely the minimum size, width, and number of lines (this overrides the width setting).
This adhesion type involves a grid with a roof system between the model and the plate. In essence, it’s a good solution when the first layer is uneven or simply refuses to stick to the plate.
The raft consists of base, middle, and top layers and you can customize it by adjusting the thickness, line size, and layer spacing. You can also adjust the Z Overlap, which will lower the design’s layers to press them onto the raft.
The skirt is a printed edge or line around the model’s first layer, but it doesn’t come into contact with the model. This binding type helps us spot any problems with the print bed before we actually print the model.
To customize the skirt, you’ll have to adjust the line count, the distance, and the size (the skirt’s length).
Is the nozzle at the right height?
The nozzle has to be correctly set up, otherwise, you won’t get that perfect first layer. If it’s too high, the filament won’t be pressed well against the plat and it will cool off due to too much contact with the air. On the other hand, if it’s too low, the material is pressed too hard and the first layer will either be too thin or it will block the nozzle.
When the nozzle is in the correct position, the material is laid down on the plate with accuracy. This way, the first layer will adhere properly. So, consider the type of filament you’re using, the size of the nozzle, the printing speed, the surface area, and make the nozzle height adjustments accordingly. You may have to experiment a few times before you nail it down.
One of the first things you’ll adjust is the temperature based on the type of material you’re using. More importantly, you can have a different temperature for the first layer. By making the initial layer print hotter than the rest, you’ll help it stick to the plate.
Just keep in mind that each material has its own temperature margins and limits. Whether you work with ABS, PLA, Nylon, or resins, you should check their temperature specifications. If you use two different materials, you should find the middle ground. In addition, the plate should also be hotter for the first layer to improve the quality of the adhesion.
Print speed is calculated in millimeters per second and we can adjust it for the entire project or for each layer. Printing at a faster rate may speed up your project, but you might end up with an ugly result. So, if you care more about the quality of your design, you need to focus on the print speed settings.
Here are a few examples of different print speeds for each section:
- Outer wall speed: You can adjust the speed at which the external surface is printed. Generally, you should pick a slower rate for this section to create a smoother finish.
- Infill speed: The rate at which you print the infill determines how fast the interior of the model is filled. If the visuals for the interior don’t matter, then pick a fast rate. However, keep in mind that speed can also affect the structural integrity of the model.
- Interior wall rate: Same as with the infill speed, if the interior wall doesn’t have to be visually pleasing or very tough, you can set up a high print rate.
- Base and leading rate: This is the print speed at which the top and lower layers are printed. To get an accurate result, a low speed is recommended both for the top and bottom. However, it’s more important for the leading layer to be printed at a reduced speed.
- Assistance infill rate: This value will impact how the sustaining framework is printed. Since the visual quality of this element doesn’t matter that much, we can choose a higher print speed.
- Assistance user interface speed: This represents the rate at which the support bottom and roof are printed. User slow speeds here otherwise the layers will lack adhesion.
When you select the infill form, you need to consider the required toughness. For instance, structural parts that have to support the weight have to be solid, but the esthetic parts can be less so. Make sure you select the right pattern for the job or you won’t get that perfect first layer.
Here are the infill patterns you can choose from:
- Rectangular: This is the most simple infill option. It works best when a solid structure is required for every direction. As a bonus, the rectangular pattern is the fastest infill you can apply.
- Triangular: It takes longer to print this infill, but it provides the model with a shell-like toughness.
- Waveform: If flexibility is required, then the waveform infill pattern is the ideal choice.
- Honeycomb: This pattern offers plenty of support for most models, but it won’t boost the print speed. It can be used for a lot of applications.
In addition, you can improve the shell thickness to reduce the amount of time needed for each infill pattern. You can also improve the quality and resilience by making sure the model is correctly cooled before the next layer is produced. Just make sure you don’t overdo it with the fan speed because quick cooling causes shrinking and cracking. Adjust it enough to prevent the material from oozing.
The first layer is the most important one because it’s the foundation of your model. Correctly printing the initial layer will ensure the design will correctly bind to the build plate and therefore make the difference between a successful print and a failed one.
Some of the most important factors to keep in mind are the print speed, nozzle height, material temperature, build plate temperature and type of filament. By making the correct adjustments you’ll maximize the chance of printing a beautiful and resilient model. Fortunately, Cura is versatile and it gives you all the tools you need to create a high-quality model. So take your time and experiment with these settings until you get the perfect first layer. It’ll be worth it once you see the end result.