Cura Ironing: What You Need to Know

Ultimaker Cura is a widely used, open-source 3D slicing software that converts 3D models into G-code, enabling 3D printers to bring designs to life. Over time, the software has gained numerous advanced features to meet the evolving needs of its users. One such feature is ironing, which was introduced to enhance the smoothness of top layers in prints. While ironing can significantly improve the aesthetic quality of models by reducing surface imperfections, it’s essential to understand when and how to use it effectively. This article delves into the functionalities, pros, cons, and settings of Cura’s ironing feature to help users optimize their 3D printing experience.

When Should You Use Ironing in 3D Printing?

3D Print with rough surface at top: Image Source: cdn.shopify.com

Ironing excels at smoothing large, flat surfaces, making it ideal for models that require minimal postprocessing. However, it’s less suited for models with intricate or curved features. The increased print time and potential risk of nozzle clogs mean that ironing should be used only when the benefits outweigh the drawbacks. For projects where the top surface quality is critical, such as decorative models, ironing can save significant time in the post-processing phase, making it a valuable tool in the 3D printing workflow.

Pros and Cons of Cura Ironing

Here’s a quick summary of the advantages and disadvantages of using Cura’s ironing feature:

Pros:

• Smooth out rough top surfaces
• Ideal for large, flat areas
• Reduces the need for post-processing, such as sanding

Cons:

• Increases overall print time
• Ineffective for curved or highly detailed surfaces
• Incorrect settings may lead to nozzle clogs

Ironing is a specialized feature that should be applied judiciously, depending on the specific needs of the print.

When Ironing Shouldn’t Be Used

While ironing offers considerable benefits, there are instances where it is better avoided:

1. Speed requirement: Ironing increases the total print time. For projects where speed is a priority, avoiding ironing can significantly reduce the printing time, especially when dealing with large surface areas.
2. Curved surfaces: Ironing works exclusively on flat surfaces. Models with curved top layers, such as spheres or domes, will not benefit from ironing. The technique cannot handle non-planar surfaces effectively, and attempting to use it on such surfaces will result in wasted time and material without improving the print quality.
3. Printer calibration: A well-calibrated printer is essential for ironing to be effective. If the printer’s extruder or nozzle is misaligned or the E-steps are not correctly calibrated, ironing can exacerbate existing issues, making the surface finish worse.

How Ironing Works

Ironing enables smooth surfaces: Image Source: forum.snapmaker.com

Ironing operates by melting protruding filament in the final layer of a print. The printer’s nozzle retraces its steps over the top surface, smoothing the material by pushing it into gaps and lowering rough areas. The added material during ironing is minimal, avoiding defects like over extrusion and blobs. 

The precision of ironing makes it a fantastic tool for prints where visual appeal is paramount, but it requires a well-calibrated printer to work effectively. Printers that are not properly tuned, especially in terms of E-steps, can produce undesirable results, making calibration crucial before using ironing.

Material Considerations for Ironing

Collection of material: Image source: printables.com

Different filament materials respond uniquely to ironing. Here are the most common filaments and how they interact with ironing:

1. ABS and ASA: These filaments are among the best choices for ironing because they are relatively resistant to heat creep. While they are easier to smooth in post-processing, ABS and ASA perform well during the ironing process due to their thermal stability.
2. PLA: Being more sensitive to temperature, PLA can encounter issues such as heat creep, which may cause more surface defects rather than improving them. To counter this, it’s important to carefully adjust the temperature settings or increase fan speed to prevent excessive heat buildup during ironing.
3. PETG: These filaments tend to struggle the most with ironing. They are prone to stringing, and ironing increases the likelihood of filament buildup on the nozzle, which can mar the print’s surface. To minimize this, careful adjustment of flow settings and extensive testing are recommended.
4. Flexible and composite filaments: Wood or flexible materials are best avoided when it comes to ironing. Their susceptibility to nozzle clogs and inconsistent behavior during extrusion can lead to poor results.

How to Activate Ironing in Cura

To enable ironing in Cura, follow these steps:

1. Open Cura and access the settings menu.
2. Ensure the “Expert” or “All” settings mode is enabled.
3. Navigate to the “Top/Bottom” section.
4. Check the box for “Enable Ironing.”

Once activated, several settings related to ironing will appear, allowing further customization of the process.

Key Ironing Settings in Cura

Once ironing is enabled, the following settings can be adjusted to fine-tune the process:

Ironing Pattern: Image Source: cdn.shopify.com

1. Iron only highest layer: Restricts ironing to the topmost layer of the print, saving time by avoiding unnecessary ironing on lower layers.
2. Ironing pattern: Two pattern options are available: “Zig Zag” and “Concentric.” These control the movement of the nozzle over the surface. The choice between patterns depends on the desired finish and the complexity of the print.
3. Monotonic Ironing order: When using the Zig Zag pattern, monotonic ironing ensures that adjacent lines are printed in the same direction for a smoother surface.
4. Ironing line spacing: This setting controls the gap between each pass of the nozzle. A smaller spacing results in a smoother surface but increases print time. The default value of 0.1 mm works well for most cases.
5. Ironing flow: The amount of filament extruded during ironing can be controlled through this setting. A flow rate of around 20–25% of normal extrusion is a good starting point.
6. Ironing Inset: This defines the distance between the outer edge of the top surface and where ironing begins. Keeping a small inset helps avoid jagged edges caused by filament buildup at the edges.
7. Ironing speed: Lower speeds usually result in a smoother finish, allowing the nozzle enough time to melt and flatten the surface. Starting with Cura’s default speed is recommended, but it can be lowered further if needed.

SelfCAD: A Powerful Alternative to Cura Slicer

SelfCAD is an intuitive 3D design software that offers an in-built online slicer, making it a fantastic alternative to Cura for slicing STL files. This unique feature allows users to design and slice their 3D models seamlessly, eliminating the need to switch between different software applications. Whether you are creating a new model or modifying an existing one, SelfCAD provides the tools you need on one convenient platform.

To get started, you can either use SelfCAD’s robust design tools to create a new 3D model or import a pre-existing file for adjustments. Before slicing, it is crucial to ensure that your model is completely enclosed and watertight, as this is essential for accurate slicing. If your model has any issues, SelfCAD’s Magic Fix tool can automatically detect and rectify common problems, ensuring your model is print-ready. The video below shows how to use the magic fix tool of SelfCAD.

Accessing the slicer is straightforward. Simply click on the “3D Slicer” option within the software. You can then select your specific 3D printer from a list of compatible devices or add your printer if it’s not already included. This flexibility allows for a tailored slicing experience that meets your particular printing needs. 

Once you’ve selected your printer, you can customize various slicing settings, including layer height, infill density, and print speed. Adjusting these parameters helps optimize your print for quality and efficiency. After configuring your settings, preview the sliced model to ensure everything appears as expected. This step is crucial for identifying any potential issues before printing.

When you are satisfied with the preview, you can easily export the G-code, which is the language that your 3D printer understands. This straightforward workflow simplifies the transition from design to print, making SelfCAD a comprehensive solution for both beginners and experienced users.

In addition to its slicing capabilities, SelfCAD includes features like sculpting, texturing, and rendering, providing a complete package for 3D modeling. Its user-friendly interface and extensive tutorials make it accessible to users of all skill levels. With SelfCAD, you not only streamline the design-to-print process but also gain access to a versatile tool that enhances your 3D printing experience.

Ironing in Cura: The Secret to Flawless Finishes

UltiMaker Cura’s ironing feature is a powerful tool for achieving smooth top layers in 3D prints. By understanding the materials, settings, and use cases where ironing excels, users can significantly improve their print quality while minimizing post-processing. Proper calibration and selective application are key to maximizing its benefits.