3D printing isn’t just a case of hitting send from your slicer to your machine. If you want to achieve high-quality 3D prints, you have to become familiar with the slicer settings.
Slicer settings are the printing parameters, like nozzle temperature and print speed, that are controlled in the 3D slicer software (e.g. Cura). While you don’t need to know every slicer setting, there are a handful of extremely important settings that significantly affect the outcome of a print.
Crucial Slicer Settings For 3D Prints
In this article, we’ll explore the most powerful slicer settings that can make all the difference in producing beautiful and useful 3D prints.
From layer height to print speed, we’ll cover what each setting does and how to adjust them to achieve the best results.
So whether you’re a seasoned 3D printing pro or just starting out, read on to learn how to get the most out of your slicer settings!
What is a Slicer?
A slicer is a type of 3D printing software that takes a digitized 3D model and converts it into instructional commands that your 3D printer can interpret and follow to create the desired physical 3D print.
In essence, the slicer takes the CAD model (STL file) and “cuts” it into layers. Think of a series of 2D pictures stacked on top of each other to create a 3D model.
The slicer software then calculates how much material needs to be used for that layer, where the material should go, and how long it will take to print.
It then converts all of the information for each layer into one GCode file which is sent to your printer. You set up the job and, voila! Sometime later you have a physical representation of the 3D CAD model.
As you can see, the slicer plays an integral role in helping turn your 3D ideas into reality. Therefore, how you use the slicer, specifically how you use the settings, is often a critical difference between printing success and failure.
In this article, we’re going to look at 6 key slicer settings that are common to all the major slicer programs. We’ll tell you what they’re for and we’ll explain how to use them to increase your chances of producing beautiful and useful objects each and every time you print.
Best 3D Printer Slicer Settings
1. Layer Height
Layer height is the 3D slicer setting that establishes the height, or thickness, of each layer of filament in your print. In some sense, layer height in 3D printing is akin to resolution in photography or videography.
But on top of the level of detail on a 3D print, the layer height also impacts the print time, part strength, and surface quality.
Smaller layer heights result in 3D prints with more layers, and this allows your machine to better capture small features and geometries on your print. Larger layer heights will have fewer layers and, thus, less detail.
Another benefit of using a smaller layer height is that prints have less visible layer lines and feel smoother due to the higher number of layers used.
Though larger layer heights produce a rough surface texture, they offer enhanced part strength and shorter print times than smaller layer heights.
For reference, the most common layer height value is 0.2 mm, as it provides a nice mix of print time, strength, detail, and surface quality.
But, if you’re printing a model, like a miniature figurine, where detail is a top priority, then consider lowering the layer height to 0.16 mm or lower.
On the other hand, if you’re printing a large box or container, where strength and print time should be prioritized over detail, then you might want to increase to 0.24 mm.
You don’t have to worry too much about the layer height setting, though, when printing PLA or ABS as both materials are pretty forgiving when it comes to this setting.
Before I move onto a different setting, though, it’s worth noting that you should try to use a layer height value that’s divisible by the Z-axis stepper motor’s step distance, also called the “magic number”.
Most printers, like the Creality Ender 3, use NEMA-17 motors that have a step distance of 0.04 mm. So, if you have one of these printers, consider using a layer height divisible by 4, like 0.16, 0.2, or 0.24 mm (add/minus 0.04 mm).
Don’t worry too much about the layer height, though, as most filaments, including PLA and ABS, are pretty forgiving when it comes to this setting. If your 3D printer has a 0.4-mm nozzle, any layer height between 0.12 and 0.28 mm should produce decent results.
2. Shell Thickness
A shell is the outer wall of a designed object. Shell thickness refers to the number of layers that the outer wall will have before infill printing will begin. The higher the setting is for shell thickness, the thicker the outer walls of your object will be.
Obviously, thicker walls make for a sturdier object, so if strength is a quality that you’re after, it pays to increase the shell thickness appropriately.
Conversely, delicate or decorative designs do not usually require strength. Increasing the shell thickness in these instances provides no real benefit and will likely distort the design of the object being printed.
You should try to set the shell thickness as a multiple of the nozzle print width, which should be equal to the nozzle size (diameter). Most printers use a 0.4-mm nozzle and print width, so shell thicknesses of 0.8, 1.2, or 1.6 mm will work best.
3. Retraction
Retraction is where the 3D printer extruder pulls back a small length of filament to relieve built-up pressure in the hot end to prevent oozing and ensure accurate extrusion. But, for retraction to occur, you need to activate the retraction setting in your 3D slicer.
The basic retraction setting is usually a checkbox, but, once activated, there are a handful of related settings that you can change to further tune the retraction process.
Easily the two most important of these are:
- Retraction length
- Retraction speed
The retraction length controls the length of filament pulled back during each retraction move, while the retraction speed controls how fast the extruder pulls the filament back.
Generally, the higher the retraction length and speed, the less you’ll experience stringing and oozing. But, adjusting too far can cause other issues, like filament grinding, hot end jams, and more.
The best values for these two settings depend on your extruder configuration.
- Bowden-drive printers, like the Prusa Mini+, work best with more intensive retraction settings, including a retraction length of 4-5 mm and a speed of 40-60 mm/s.
- Direct drive printers, like the Prusa i3 MK3S+, yield better results with lower retraction settings, like a length of 0.5-1.0 mm and a speed of 30-50 mm/s.
4. Fill Density
Infill density is a measure of how much material will be printed inside the outer shell of the object in question. Fill density is usually measured as a percentage of the whole, as opposed to a unit of measure.
This means that if 100% fill density is selected, the printed object will be solid, with no empty space inside the outer shell. Likewise, if 0% is selected, the object will be printed hollow.
Generally, an object with more infill will be stronger and heavier than an object with less infill – but will take noticeably longer to print.
A typical infill density is around 20%. This provides a nice mix of print time, part strength, material usage, and weight. However, feel free to increase this value for more strength (or weight) or decrease it to save material and print time.
In general, when printing PLA and ABS, you should try keeping the infill density between 10 and 30%:
- Densities below 10% are extremely weak while not saving much filament or time.
- Densities above 30% consume an excessive amount of filament without providing much additional strength – so it’s not worth the cost.
Infill Pattern
The infill pattern is another infill slicer setting, and it controls the shape and structure of the internal filling of the print.
The infill pattern affects a part’s strength, weight, and print time. There are trade-offs with different infill patterns, and those that provide more strength usually cost you additional print time and filament.
Some common infill patterns, available in most 3D slicers, include grid, lines, cubic, concentric, gyroid, and honeycomb. I’ve briefly gone over a few of these infill patterns and their benefits:
- Grid: The grid infill pattern is one of the simplest, hence why it’s so commonly used. Not only does the grid infill pattern help ensure a successful print, but it also provides a nice mix of low print times and decent part strength.
- Cubic: The cubic infill pattern provides high strength across all axes of the model, and it also doesn’t add too much print time. Cubic is my personal favorite infill pattern and I use it for both generic and functional prints.
- Concentric: This infill pattern is great for printing flexible models, where you want the walls to be able to bend and fold.
- Gyroid: The gyroid infill pattern offers equal strength across all directions, and it looks super cool when exposed (no shell layers).
5. Print Speed
Print speed is how fast the print head travels while extruding filament. Therefore, the optimal print speed depends on the object you’re printing and the filament material that you are using.
In general, simple objects with less detail can be printed faster without any issues, so it’s recommended to use higher speeds for these types of models. But if you’re printing a complex model with intricate features, use a lower print speed.
Your slicer’s default print speed will depend on your printer, extruder, layer height, material, and a few other factors. However, I suggest adjusting the value based on how complex and delicate your print is.
A print speed between 40 and 60 mm/s is typical for PLA and ABS, but, remember, you will likely have to adjust.
Furthermore, if you’re experiencing issues like under-extrusion on prints, consider lowering the print speed as the setting is (typically) indirectly correlated with print quality. However, note that certain issues, like stringing and blobbing, can result from too low of a print speed, so keep this in mind.
6. Bottom/Top Thickness
This setting determines how much material will be laid down before the infill printing starts and how much material will be laid down after the infill printing is finished. The thickness of the material at the top and bottom of your object is important for two reasons.
First, thicker material at the bottom of your object will provide a stronger and more stable base. Second, thicker material at the top of your object will prevent sagging and pillowing from occurring when the top layer of material is laid down over the infill lattice.
This is especially important if you are using a smaller layer height setting. In such a case, the thinness of the layer can be insufficient to completely cover the infill unless multiple layers are used.
Setting the bottom/top thickness to be 6 to 8 times greater than the layer height ensures that there is enough material being laid down to adequately cover the infill without complications.
7. Spiralize – Smooth out the Z Scar
If you’ve printed an object and on one side there appears a vertical scar all the way up the print, this is called a Z scar (also known as a “zipper”). It’s formed from the printer starting and stopping each layer at this point.
This scar can be unsightly, and on very thin prints also significantly weaken the structure.
To remove the Z scar, you’re going to need to activate the Spiralize feature in your slicer. This makes the outer layers print in a continuous line all the way up the print, meaning there’s no definitive stop and start point and therefore no scar formed.
To activate Spiralize feature and remove the vertical scar:
In Cura, it’s called the “Spiralize outer contour” feature, in other slicers it may be slightly different. Make sure this option is checked when you convert your STL file to a Gcode.
It is useful to remember to only change one slicer setting at a time so that you can see the effect that the change is having on your print. If the change is beneficial, write down the change that was made and proceed, if necessary, to change another setting.
Changing multiple settings at the same time can cause chaotic conditions and a positive effect can be canceled out by one or more negative effects.
It may be useful when planning prints to know the length of filament on each size spool for various materials and sizes. To help with this, we’ve created this filament calculator.
8. Temperature
Temperature is easily one of the most important slicer settings for a 3D print. Typically, there are two main temperature slicer settings: the nozzle temperature and the bed temperature (for heated beds).
In the sub-sections below, I’ve gone over everything you should know for each type of temperature setting!
Nozzle Temperature
The nozzle temperature, sometimes called the printing temperature, affects the flow of filament material.
You should set the nozzle temperature based on the filament material you’re using, as different materials can work with vastly different temperatures.
For example, PLA filaments work best with a nozzle temperature of 190-215°C, while ABS filaments work better with a higher nozzle temperature of 220-240°C.
It’s important to tune the nozzle temperature because too high a value can cause over-extrusion issues, like stringing, blobbing, and zits on the surface of the print due to the accelerated melting process.
However, using too low nozzle temperature causes under-extrusion (e.g. gaps in the layers), as well as weaker, more brittle parts due to weaker layer-to-layer bonds.
While you don’t need to be spot-on when setting the nozzle temperature, I suggest printing a temperature tower model to evaluate which temperature works best with your specific filament spool.
So, make sure to try a few different nozzle temperatures so you can find that “Goldilocks” value!
Bed Temperature
Bed temperature is also very important. But, unlike the nozzle temperature which affects material flow, the bed temperature mainly impacts bed adhesion, or how well 3D prints stick to the print surface.
Generally, the higher the bed temperature, the better the bed adhesion. And, just like with nozzle temperature, what bed temperature is best depends on the filament material you’re printing.
If you’re printing PLA, while technically you don’t need a heated bed (0°C), it’s recommended to use a bed temperature between 50°C and 60°C.
But, if you’re printing ABS, you’ll need to use a much higher bed temperature, somewhere between 90°C and 110°C, as this material softens at higher temperatures.
9. Flow Rate
Flow rate, also known as the extrusion multiplier, is a slicer setting that controls the true extrusion of filament.
The flow rate is extremely useful for preventing over and under-extrusion, resulting in better-detailed, stronger prints. Flow rate can also help you achieve more dimensionally-accurate prints.
Ideally, the flow rate should be 100%, meaning that the printer will use exactly the estimated length of filament to produce the model. However, many external factors, from the extruder E-steps to the nozzle temperature, impact filament extrusion. So, 100% typically isn’t the best E-steps value to use if you’re looking to produce a dimensionally-accurate model.
For example, let’s say that you’re printing a 3DBenchy but your machine typically under-extrudes prints by 2-5%. 3D printing with a 100% flow rate would result in an under-extruded model, with gaps in the layers, so it would be best to either increase the flow rate or fix other extrusion-related issues (e.g. partial nozzle clogs).
It’s important not to confuse the flow rate slicer setting with the E-steps value, which controls the extruder motor’s motion. Moreover, while E-steps can also be used to combat extrusion issues, the E-steps value is inherently a physical machine parameter, not a digital slicer setting like flow rate.
Generally, your flow rate won’t be outside the 90-100% range, but this depends on your specific printer.
If your 3D prints don’t show any noticeable over-extrusion, under-extrusion, or dimensional accuracy issues, I recommend leaving the flow rate setting alone. But, if you’re experiencing one of these problems, I suggest following a flow rate tuning guide, like this video tutorial.
10. Cooling
The cooling process is critical to the quality of any 3D print, especially when printing overhangs or other delicate geometries. The fan speed slicer setting is best for managing your printer’s cooling levels, and it controls how fast the part-cooling fan (the one pointed at the nozzle) is spinning.
Depending on your 3D slicer software, the fan speed slicer setting is set as either a percentage or absolute value. And, as you might expect, the higher the fan speed, the more cooling is provided during the printing process.
The optimal fan speed value depends on your filament and the model you’re printing. PLA requires moderate cooling, so an 80-100% fan speed is typical, but materials like PETG and PC work better with lower fan speeds, like 20-50%.
And then there are some materials, like ABS, where it’s recommended to completely turn off part cooling (0% fan speed).
Additionally, if your model has a lot of overhangs or bridging features, you’ll want to use a higher fan speed. That’s because using too low of a fan speed can cause drooping with overhangs and bridges.
Conversely, make sure not to set the fan speed too high as this can cause layer separation and cracking on prints.
However, one exception to all of these generalizations is the first layer. The fan is typically turned off during the first layer to improve the bottom surface and bed adhesion, and you should check that your slicer’s first-layer fan speed is 0%.
11. Supports
Supports are slicer-generated structures that hold up overhanging features on models. Supports aren’t on every print as you’re only supposed to use them when absolutely necessary, as they require additional filament material, extend print time, and hurt the surface finish of your model.
However, if you’re printing a model with a significant overhang (>55°), supports are necessary for a successful print. And there are a few slicer parameters, besides the basic “Activate Supports” setting, that you can use to tune how supports are generated and printed.
I’ve listed and briefly described a few critical slicer settings related to supports:
- Support Type: Depending on your slicer software, you might have multiple options for the type of support structures that are generated. The two most popular options are regular (rectilinear) and tree supports, and the latter is considered better for handling overhangs in difficult-to-reach places. Both PLA and ABS work well with regular and tree supports, so feel free to use either.
- Overhang Angle: The support overhang angle is a fairly-universal slicer setting that controls the minimum steepness of an overhang area for the slicer to generate support structures. The higher this value, set in degrees, the fewer support structures will be printed. I suggest setting the overhang angle to 50-55°, and increasing if you feel comfortable.
- Minimum Support Area: The minimum support area setting controls how large an overhang area must be for the slicer to generate support structures. The large the value, set in millimeters, the fewer support structures will be printed.
- Support Z Distance: Lastly, this setting controls the gap that the printer leaves between the top of a support structure and the beginning of the actual model. A larger support Z distance will make removing support structures from your model after printing easier. For PLA and ABS, I suggest keeping this setting between 0.1 and 0.3 mm.
12. Adhesive Aids
Lastly, adhesive aids are a class of slicer settings that are critical to achieving adequate bed adhesion on prints. If you’re unfamiliar with the term, “adhesive aids” refers to slicer-generated structures that are printed before your actual model to ensure the first layer properly adheres to the print surface.
If the first layer doesn’t stick well to the bed, then your print might fail completely, or, in the best case, your print will be warped and dimensionally inaccurate. As such, knowing what adhesive aid to use is critical to a successful print.
There are three types of adhesive aids: skirts, brims, and rafts. Each offers different advantages and disadvantages, and I’ve described each in the bullet points below:
- Skirt: A distant and detached perimeter that outlines a print, useful for getting material flowing smoothly and making last-minute bed leveling adjustments.
- Brim: Extra filament extruded as concentric rings from a print’s first layer, helpful for prints with a small “footprint” or low surface area contact with the bed.
- Raft: An entire part on its own upon which the model is built, useful for preventing warping and ensuring the print doesn’t have to touch the surface.
Here’s a simple breakdown of the different properties of each type of adhesive aid:
Adhesive Aid | Skirt | Brim | Raft |
---|---|---|---|
Bed Adhesion | Low | Medium | High |
Filament Usage | Low | Medium | High |
Added Print Time | Low | Medium | High |
I suggest using a skirt when you have no issues with bed adhesion, a brim for minor bed adhesion issues, and a raft if you’re dealing with warping every print job.
If you’re printing PLA, a skirt or a brim is usually all you need. However, other filament materials, like ABS and PC, are known to have more bed adhesion issues, so you’ll want to use either a brim or raft.
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