How to Use Tree Supports in Cura for Perfect Prints

UltiMaker's Cura software is a powerful, free, open-source slicer highly favored by numerous 3D printing enthusiasts. Today, we're discussing tree supports in Cura's settings and how to add them for optimal printing results on your model. You can also find similar features in another popular slicer, PrusaSlicer, called 'Organic Supports'. Before delving into this kind of supports, it's essential to understand why applying supports is necessary in 3D printing, especially for models with complex geometries. Typically, overhangs exceeding 45° or long bridges require support materials to ensure 3D prints do not sag or collapse during printing. This means that supports are a useful tool that allows you to freely print complex models.

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What Are Tree Supports in 3D Printing?

3D print tree support

(Printed by Anycubic Kobra 2 Pro)

Tree supports, as the name implies, simulate the structure of real tree trunks and branches by extending from the base in multiple directions to wrap around the print. The tips of the branches connect to the overhanging of the object, preventing layer collapse during printing.

In contrast to normal supports, tree supports offer more flexibility as they can be printed at different angles, reducing contact points with the object. This method allows for easier removal of supports, resulting in cleaner finishes even on complex prints, while also reducing material usage and print time. Tree supports also have a drawback, but it is minor - They require longer slicing times compared to normal supports, as the software needs more computation time.

Advantages of tree supports:

  • Easy support removal
  • Easier sanding
  • Material savings
  • Faster printing time

Disadvantages of tree supports:

  • Longer time for slicing

How Do I Enable Tree Support in Cura?

Cura tree support

The default support in Cura is set to 'Normal' rather than 'Tree', but it's easy to locate the tree support feature and activate it. Once all settings are visible, navigate to 'Support' in the print settings, then select 'Tree' from the dropdown menu under 'Support Structure'.

Best Tree Support Settings in Cura

Cura tree supports

After enabling the tree support structure in Cura, adjust the unlocked parameters based on your needs and preferences. There are several important parameters that you need to understand in order to achieve the best settings for the tree structure to protect your parts during printing.

1. Support Placement

This setting is also common with normal supports, offering two options: "Touching Buildplate" and "Everywhere". The former means that supports are generated only from the plate upwards and connect to the model's overhangs, and there is no any layer between these overhangs and the platform. This will generate fewer supports compared to the latter, thus saving material and printing time.

Meanwhile, "Everywhere" is that supports are generated at any overhanging part of the model, suitable for complex models to maintain printing stability. However, it increases the difficulty of support removal and leaves more support marks that need to be sanded.

2. Trunk Diameter

It is easy to understand that this indicates the thickness of the trunk, with thicker trunks being sturdier. If the nozzle accidentally hits the object mid-print, thick trunks can prevent the model from toppling over easily.

3. Branch Diameter

This is also easily understood that thicker branches indicate a larger diameter and also contribute to greater stability. However, the trunk diameter must be larger than the branch diameter; otherwise, it will create an unstable  top-heavy support structure.

4. Branch Diameter Angle

It controls the angle of the branches' diameter when branches towards the base. An angle of 0 will maintain a constant branch diameter, while higher values widen the base of the branches, enhancing stability. Typically, angles between 3-5 degrees are suitable for normal overhangs.

5. Maximum Branch Angle

The maximum branch angle controls the inclination of the branches. A higher value makes these branches lean more from the main trunk, allowing better contact with the model. Conversely, a lower value causes the branches to tend more vertically upwards, resulting in a sturdy support structure and more stable printing. In Cura, the default value for this is 50°.