3D slicing is the process of taking a 3D model and converting it into instructions that the printer can understand. It is an essential step in the 3D printing process, and it’s important to know how it works and how you can slice your 3D models using popular and industry-standard 3D slicers like Cura.

How 3D Slicing Works

A 3D model of a gear opened in SelfCAD slicer ready for 3D slicing

3D printers work by reading 3D files and printing them layer by layer, usually in thin layers of about 0.1mm thick. A 3D slicer takes your 3D model and translates it into a language your 3D printer can understand, which is called a G-code.

The G-code file contains instructions for each model layer so that your 3D printer knows what to do. The file contains the instructions like how the printer should move, what speed to use, and the size of the 3D printer filament to extrude.

When creating a G-code file it is essential to ensure that the instructions are clear and accurate. Incorrect instructions can result in poorly designed parts or even damage the machine. Once you create the G-code file, there is an option to modify it if necessary.

The Important Settings in 3D Slicers

There are several basic settings found in most 3D slicers. One of them is the infill percentage. The infill is the amount of material the printer adds inside the object. A lower infill percentage means you use less material, and the design will be lighter. A higher infill percentage means you use more material, and the 3D object will be more robust.

The slicer software allows you to select the type of infill pattern you want. Examples of infill patterns include the honeycomb, octagon, and zigzag. Each infill pattern has advantages and disadvantages. For example, octagon patterns use less material than other patterns, and zigzag patterns are robust.

Infill patterns option in Cura slicer

3D slicing software also allows you to add support structures to your model. 3D printing supports are essential for holding parts of the model that would otherwise collapse during printing. Printing some objects, especially those with overhangs, would be challenging without support structures.

You can also select the type of nozzle you want for your printer in the slicer. Nozzles are made of plastic, brass, or stainless steel, and they come in different sizes and materials, and the most common nozzle sizes are 0.4mm and 0.2mm.

There are many other settings that you can adjust in 3D slicing software, but these are some of the most important ones. Let's now have a look at how you can slice your models using Cura, the popular 3D slicer, and SelfCAD's in-built slicer.

Steps to Slice a Model Using Cura

Once you have downloaded and installed Cura, launch it and go to File > Open File(s), and this will bring up a window where you can locate and select the file containing your 3D model. Then click Open in the bottom-right corner of the window. Your model should now appear in the Cura workspace.

To customize your slicing settings, go to Fine > Custom. As shown below, a new window will open where you can adjust various parameters such as walls, infill density, and supports settings.

The custom settings of Cura 3D slicer

Once you are happy with the settings, click Slice at the bottom of the window, and the slicing process will start. Once completed, there is an option to preview your design and see how it will be 3D printed, as shown below.

Previewing a model in Cura and showing how it will be printed

When you are done, you can click Save to Disk, and you’ll see several options to save your design. We recommend saving either as a G-code, OBJ, or STL file, as these are the formats that a 3D printer can read.

Steps to Slice a 3D Model Using SelfCAD

SelfCAD is a 3D modeling software that comes with an in-built STL slicer. Once you have designed your 3D model and are ready to slice, you can access the 3D slicer by selecting the 3D Print tool in the menu bar's top-right section.

An option to access the slicer of SelfCAD

Once you click the 3D Print option, you will see a new window where you'll select your 3D printer and then have access to several settings configured to slice your design. The first setting is Quality, where you can choose from six options to set the quality of your 3D print.

Another important setting is the Infill percentage, which determines how much of the internal volume of a 3D model should be filled in with plastic when slicing. For instance, you can lower this percentage if you want to save material and weight. On the other hand, if you want to maximize strength and durability, you can increase it.

The other main settings are Support and Material. The Support option allows you to choose if your 3D model should have support structures, while the Material option enables you to select the material with which you want your design to be 3D printed.

The different settings of SelfCAD slicer

Finally, we have the Settings option where you can find more settings. One of them is the Layer Height which allows you to specify how thick each layer should be when slicing your 3D model. This will determine how much detail is captured in each layer and impact the overall print time depending on how small/large it is set.

Another setting here is Shell, where you can set how thick the outer walls of a 3D model should be. This impacts the overall strength of the structure and its ability to withstand different types of stress or pressure. Depending on what kind of object you are printing, this setting could also impact print time and material cost efficiency.

Once you configure all the settings, you can select Slice, and the software will generate the G-code file you can send to your 3D printer. Just like in Cura, you can also preview your design and know the amount of material required and the printing time.

Benefits of 3D Slicing

  • Easy customization: You can specify the thickness of the walls, the 3D printing speed, and even the fill density of the object. Using slicing software like Cura, you can also split an object into several parts.
  • Reduced waste and cost savings: You can reduce the cost significantly since you can specify the thickness of your design and other settings involving the usage of materials and the model's overall design.
  • Know the material size to be used: During 3D slicing, you can see the material size your project will require, which helps you plan.
  • Know the time it will take to 3D print your model: In addition to seeing the size of the material that your project will require, you will discover the amount of time it will take to complete it.

Prepare Your Designs for 3D Printing With a Slicer

3D printing is a fantastic technology that allows you to create 3D objects from a digital file. However, 3D printers cannot understand the 3D model as it is: you must first convert it into a format they understand, and this is the work of a 3D slicer. There are various slicing programs out there that can do this for you, but it's essential to choose one that is compatible with your particular printer. We hope that the two slicers described here can help you get started easily.