One of the core steps of 3D printing is slicing. A good 3D printing slicer software must have a high degree of freedom to fully realize the designer's ingenuity and the performance of the 3D printer. Cura, published by Ultimaker, is one such software. It not only allows for basic settings but also has an advanced mode that lets users meticulously adjust various printing parameters and details, such as layer thickness, support, infill density, printing speed, and more. All kinds of settings are available, allowing 3D printing enthusiasts to unleash their maximum creativity. Let's take a look at how to operate version 15.06, designed for the Ultimaker series!

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Installation

Please go to the official website to download and install Cura version 15.06. Before installation, remember to check the following points to ensure your computer system is compatible!

Operating System
•    Windows Vista and newer
•    Mac OSX 10.7 and newer
•    Linux Ubuntu 15.04, Fedora 23, OpenSuse 13.2, ArchLinux and newer

Processor
•    OpenGL 2 compatible graphics chip
•    Intel Core 2 or AMD Athlon 64 or newer

Supported File Types
•    STL (most common 3D printing file format)
•    OBJ

Operation Interface

The image below shows Cura's operation interface. You can set your preferred print parameters in Cura and then slice your object.



1. Menu Bar
2. Open File
3. Operation Mode
4. Print Settings
5. Mirror
6. Rotate
7. Scale
8. Save G-code file

Preparing Print Files

Follow these basic steps to choose your preferred print settings and convert your 3D object into a G-code file.

Opening a File
•    Click the "Open file" button in the top left corner of the screen.
•    Select "File" > "Open."
•    Select the file and open it ("Open with").
•    Drag and drop the file from your computer into Cura.

Settings
When you first open Cura, it will be in "Simple" mode. You will find a "Time vs Quality" slider. Adjust this slider to fine-tune your preferred settings. Sliding it to the far left, "Minimum Draft," will quickly print objects with lower quality. If you desire high print quality, slide the bar to the far right, "Maximum Quality," though this will result in longer print times. You can position the slider anywhere along the axis to find your preferred balance between quality and time. Cura will then calculate parameters such as layer thickness, infill density, and print speed based on the slider's position.


If the object you are printing has overhanging structures, you must enable support material. Please check "Enable Support," and Cura will automatically calculate and generate the support material.

Saving the File
Once the parameters are set, Cura will slice the 3D object into a G-code file. Cura will re-slice in real-time each time you change a parameter. You can see the slicing status in the progress bar at the bottom right. After slicing is complete, you can save the file by following these steps:
•    Insert an SD card into your computer (Ultimaker reads from the SD card for printing).
•    Click "Save to SD Card" in the bottom right corner of the screen, or click "File" > "Save" to save.
Note: Above "Save to SD Card," Cura displays the estimated print time and material weight, which can help you assess your upcoming print!

Adjusting the Object

Here are a few methods for adjusting the object's orientation and size.

Mirror
Click on the object, and three icons will appear in the bottom left corner of the interface. The leftmost one is the mirror function. Click the mirror function, and arrows for the X, Y, and Z axes will appear on the object. Click any arrow to mirror the object.


Rotate
The middle icon in the bottom left corner of the interface is the rotate function. Clicking it allows you to rotate the object along the X, Y, and Z axes. Holding down the left mouse button on one of the axes will move it 15 degrees at a time. Alternatively, holding down the "Shift" key (or unchecking "Snap Rotation") will allow for single-degree movements. (Pressing "Reset" will return the object to its original position.)


Scale
The rightmost icon in the bottom left corner of the interface is the scale function, which allows you to scale the object along the X, Y, and Z axes. Here are a few ways to operate it:
•    Drag the small square on any axis of the object to scale it.
•    Directly adjust the size values in the "Scale" function.
•    Adjust the percentage in the "Scale" function to scale.
The default scaling is uniform across the X, Y, and Z directions. You can uncheck "Uniform scale" to adjust each direction independently.



The "Scale" function also includes "Reset" and "Scale to max" icons. "Reset" returns the object to its original size, while "Scale to max" enlarges the object to the maximum printable size within the build volume.

Mouse Controls

Change View Angle
You can change the view angle and zoom using your mouse to observe object details.

Left Click:
Move the mouse cursor over an object and left-click to move the object's position on the X-Y plane.

Move Interface:
You can hold down "Shift" on your keyboard and the right mouse button simultaneously to move the entire Cura interface.

Rotate:
Press the right mouse button to rotate the view angle to observe the object from various angles. If your mouse only has one button, press the spacebar and the mouse button simultaneously to rotate the view angle.

Zoom:
Zoom in and out using the mouse scroll wheel; scroll forward to zoom in, and backward to zoom out.

Right-click on an object
Right-clicking on an object under the cursor will bring up a menu.
•    Center object on platform: Centers the object on the build plate.
•    Delete object: Removes the object.
•    Duplicate object: Creates a copy of the object on the build plate.
•    Clear build platform: Clears all objects from the build plate.
•    Reload all objects: Reloads all objects on the build plate.
•    Reset all object positions: Returns all objects on the build plate to their initial positions.
•    Reset all object transformations: Reverts the object to its initial settings.



View Modes

Clicking "View mode" in the top right corner of the interface will display two object viewing modes to choose from.

SOLID
This is the default view mode, where you can clearly see the object's size and shape.

LAYERS
Layer mode (also called slice mode) is a very useful mode. In this mode, you can view each layer after slicing. It is recommended to enable this mode before printing to check for any issues after the object has been sliced. Note: In layer mode, you can move the slider on the right up and down to view each layer.
The different colors you see in layer mode represent different meanings:
•    Red: Outermost perimeter (outer wall) of the object.
•    Green: Second outer perimeter (inner wall).
•    Yellow: Infill / Top and bottom surfaces.
•    Blue: Support structures / Brim / Raft.



Firmware

New versions of Cura (including new firmware versions) are released on the official website periodically. It is recommended to regularly check the official website to keep both Cura and your machine's firmware updated to the latest version. Please follow these steps to update the firmware:

1. Connect    
Connect your computer to the Ultimaker using a USB cable. Remember that Ultimaker 2 series and Ultimaker Original+ machines must be powered on and connected to power.

2. Update Firmware
Open Cura and go to "Extensions" > "Firmware" > "Update Firmware" (please confirm that the correct machine is selected in the "Machine menu"). Cura will automatically update the latest firmware to the machine.

Using Advanced Mode

Cura defaults to "Simple mode." You can select "Advanced mode" above the "Print Setup" option.

Interface Layout
The interface layout for Advanced Mode in Cura version 15.06 differs from previous versions. It defaults to displaying the most common adjustment items, but you can configure more settings in Cura. Version 15.06 offers more configurable items than previous versions.
Please follow these steps to set up:

• Click "Machine" > "Configure printers" in the menu bar to bring up a menu with all print parameter settings.
• Once checked, you can configure them in the "Print Setup" on the right.

Next, we will briefly describe the meaning and purpose of each option.


Quality

The following important parameter settings determine the surface quality of the printed object.

LAYER HEIGHT
Layer height is probably the most frequently adjusted parameter. The default layer height is 0.1mm. You can decrease the layer height for better surface quality or increase it to shorten print time.

SHELL THICKNESS
Shell thickness is one of the items displayed by default in advanced mode, used to determine the number of perimeters (layers) for the printed object's shell. The default is usually 0.8mm (meaning two perimeters when printing with a 0.4mm nozzle). For most objects, this shell thickness is strong enough.

BOTTOM/TOP THICKNESS (Bottom/Top Layer Thickness)
This option sets the thickness of the object's bottom and top layers. The default is 0.8mm (if the layer height is set to 0.1mm, this means 8 layers). However, in some special cases, it may be necessary to increase the thickness. For example, if you are printing a large, flat top surface, or if your object requires a lower infill density, a thicker top layer is needed to seal the object. Using too thin a top layer with a low infill density can lead to a phenomenon commonly known as "pillowing," as shown in the image below.


BOTTOM/TOP PATTERN (Bottom/Top Pattern Type)
This option allows you to change the pattern style of the bottom/top layers. The default prints a line pattern; you can use a concentric pattern style instead of the default.


Material

In Cura, various material-related settings can be configured, but you'll find that most options are set on Ultimaker 2 series machines. However, if you own an Ultimaker Original or Ultimaker Original+, you will still need to perform these settings in Cura.

TEMPERATURES

Using the correct temperature is one of the most crucial aspects of 3D printing. If you are using an Ultimaker 2 Go, Ultimaker 2, or Ultimaker 2 Extended, you will find that temperature-related adjustments are configured on the machine itself. However, if you are using an Ultimaker Original or Ultimaker Original+, you will still need to make these settings in Cura. Here, we will discuss the temperatures for the nozzle and the heated bed (if configured).
The default settings in Cura are for PLA, and we recommend a nozzle temperature of 210°C and a heated bed temperature of 60°C. For ABS material, a nozzle temperature of 250°C and a heated bed of 90°C are recommended. If you wish to use other materials, you must find suitable temperatures to ensure the material can be fully extruded. This means you will need to change the temperature in Cura according to your chosen material. If you are using an Ultimaker 2 series, you can simply select the appropriate configuration on the machine.

RETRACTION

This is a setting that can be found and enabled on any 3D printer. Retraction refers to the filament being automatically pulled back a short distance when the nozzle moves to an area that does not require printing. For example, when printing two pillars with a certain distance between them, retraction ensures that the nozzle only moves without extruding any plastic, preventing "stringing" (fine plastic strands between different objects). The image below shows stringing that occurs if retraction is disabled.

Sample of stringing

Enabling retraction usually yields excellent results, but you might occasionally still see some stringing. In such cases, you can try lowering the nozzle temperature to reduce the amount of plastic flowing out of the nozzle, thereby preventing stringing. However, note that lowering the nozzle temperature also means you (may) need to slow down the printing speed to ensure the plastic is fully melted when it exits the nozzle.

DIAMETER AND FLOW

These two settings are used to adjust the diameter of the filament you are using and the flow rate of the extruded material. Although you are unlikely to change them, it's always good to understand the relevant knowledge.
DIAMETER refers to the diameter of the filament you are using. Ultimaker's supplied materials consistently measure 2.85mm, but materials from other suppliers might differ slightly. In such cases, it is recommended to measure the filament diameter with a caliper and make changes in Cura. Based on the value you set, Cura calculates how much plastic needs to be extruded. However, note that Ultimaker is not designed for 1.75mm filament, so it is recommended to use filament with a diameter of approximately 2.85mm.
Based on the filament diameter and print speed, the amount of plastic that must be extruded per unit of time is calculated as the FLOW. The flow setting is usually kept at 100%, meaning the material extrusion perfectly matches the required amount. Typically, you do not need to change this setting because Cura automatically calculates the correct flow. However, if you are printing with softer materials (like flexible filament TPE), you might need to slightly increase the flow because softer materials will have deeper bite marks from the feeder motor, which can slightly affect the amount to be extruded. There is no recommended default setting for this (as the softness of each flexible material varies), and you might need to experiment to find the most suitable extrusion amount.

Tip: Don't try to solve incomplete extrusion problems by increasing the flow rate; this is only a temporary solution, and the problem will not be resolved.

Speed

PRINT SPEED

Print speed refers to the speed at which the print head moves during printing, and the speed at which plastic needs to be extruded at that speed. By default, the print speed is 50mm/s. You can easily increase your print speed with this setting, but remember that when you increase the print speed, you (may) also need to increase the temperature to ensure the filament is fully melted.

TRAVEL SPEED

Travel speed refers to the speed at which the print head moves when it is not printing. This means the speed at which the print head moves from one point to another or between multiple objects when printing them simultaneously.

OTHER SPEED SETTINGS
In addition to these default speed settings, precise adjustments can be made for specific parts. Below is a brief overview of the speeds you can adjust:

- Infill speed
- Outer shell speed
- Top/bottom speed
- Support speed
- Bottom layer speed

If you want to adjust these different speed settings, we recommend making them proportionally higher to accelerate your Ultimaker's motors, rather than setting them to random values or slowing them down.

Infill

This setting determines the strength of your printed object because it defines the internal structure of the printed object.

INFILL DENSITY

The most important infill setting is infill density, which determines how much plastic will fill the interior of the printed object. A higher infill density means more densely packed plastic within the object, resulting in greater structural strength. Generally, a density of 10% to 20% is sufficient for the rigidity required by most objects, but it can be increased if needed. If you want the printed object to be completely hollow, you can achieve this by setting the density to 0%, but be aware that the top of the object may collapse without internal infill support.

Various infill percentages (10%, 25% and 50%)

INFILL THICKNESS

This interesting feature was added in Cura 15.06. If the quality and appearance of the internal infill are not important to you, it allows you to print the infill with a different layer thickness than other parts. This means you can use a higher layer thickness for the infill to shorten the overall print time. When using this option, you must ensure that the infill thickness is a multiple of the object's layer thickness. For example, if your object uses a layer height of 0.1mm, you can choose an infill thickness of 0.2mm.

Cooling

Cooling the plastic after extrusion is extremely important, so the nozzle cooling fan is enabled by default. If the plastic cannot cool quickly enough, there may be some collapse, and the quality you get will mostly be like the situation below (as shown in the figure), with an unsightly surface. If you delve deeper, there are more parameters that can be adjusted here, such as: you can turn on the fan at a specific height and operate it at a certain speed.


If not cooled properly, surface quality will be affected.

MINIMAL LAYER TIME AND MINIMUM SPEED

These two settings have many interdependencies. Minimal layer time indicates the minimum time (in seconds) required to print one layer, ensuring sufficient cooling time for each layer before proceeding to the next. Additionally, minimum speed defines the lowest printing speed.
Increasing the minimal layer time might lead to a decrease in print speed (because each layer must at least meet the minimal layer time). You don't want the printer to slow down too much. If the print speed falls below 10mm/s, it can cause quality issues because the print head will stay in the same place heating the plastic for too long. Therefore, a good balance between these settings is crucial. Under default conditions, you'll see a minimal layer time of 5 seconds and a minimum speed of 10mm/s.

LIFT HEAD

Changing the minimum layer time and speed is not always the best solution. If your model has a very small top (e.g., a pyramid), even if you adjust the above two settings, the top might still have many spots or collapse. This is because, in such cases, the material doesn't get enough cooling time. This is when you can enable the "Lift Head" function. This will cause the print head to temporarily move away from the printed object to allow sufficient cooling time (based on the minimal layer time) before returning to continue printing.
 

Support

Some objects have overhanging parts, meaning you will need to build support structures to hold up the overhanging parts to prevent sagging or falling.
 

PLACEMENT

Cura offers two support placement options: "Touching buildplate" and "Everywhere." "Touching buildplate" supports will only connect to overhanging parts that can be reached from the print bed. "Everywhere" supports, in addition to connecting to overhanging parts that can be reached from the print bed, can also create supports on the object's outer surface or inside.
 


OVERHANG ANGLE
This setting determines the degree of overhang that requires support. The default is 60 degrees (0 degrees being vertically upwards), meaning only objects with an overhang of 60 degrees or more will have supports. Setting it to 0 degrees means all overhangs will have supports, while 90 degrees means no supports will be generated.

TOWERS
Cura 15.06 has improved support structures, with "towers" being one such improvement. This reduces the contact area where the support structure meets the object at the top, minimizing marks left after support removal.

Platform Adhesion

If your object's bottom surface is uneven, or you want to increase adhesion between the object and the platform, you can select "Brim" or "Raft" under "Type." If you select "None," the nozzle will only print a "Skirt" around the first layer.

SKIRT
A skirt is a single outline printed around the first layer of the object. This feature helps the nozzle prime, and allows for checking platform leveling, filament adhesion, and extrusion status.

BRIM
A brim consists of several extra plastic lines printed outwards from the object's first layer. These extra printed lines are attached to the object and are used to increase the object's bottom surface area, thereby enhancing adhesion between the object and the platform and reducing warping. It is recommended to enable this feature when printing very large, small, or thin objects, and also when printing plastics with high shrinkage, such as ABS, to reduce warping.



RAFT
A raft is an extra mesh-like structure built between the bottom of the object and the platform. This feature is highly suitable for ensuring adhesion between the object and the platform when printing objects with uneven bottom surfaces or small contact areas.

Source: https://ultimaker.com/en/support/software/cura-1506
Translated by: 3DMART Ltd.

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