Basics of printing - Orientation and support

Model Orientation and Supports in 3D Printing

Our #PrintingBasics series continues, where we explore the key settings and principles of 3D printing step by step.
This time we take a closer look at model orientation and the use of supports, and how these factors affect the success, duration, and quality of a print.
Such decisions often determine, almost invisibly, whether a print turns out perfect, or ends up distorted, flawed, and time-consuming.

Why orientation matters

The essence of 3D printing lies in layer-by-layer construction. Each new layer relies on the one below it, so if a section extends into open air, the printer cannot properly support it.
Orientation is therefore not merely an aesthetic choice, but the foundation of stability and successful layer formation.
Properly setting the model’s orientation reduces the number of supports, shortens print time, improves surface finish, and increases structural strength (Brenken et al., 2018).

When positioning a model, it is best to minimize the number of “floating” sections.
If the model has a flat surface, placing it directly on the build plate ensures good adhesion and a uniform first layer.
Angled or tilted orientations can often help avoid overhangs and reduce the amount of support material needed.
The preview mode of the slicer software is essential in this process: viewing the print layer by layer reveals where the printer would attempt to build in midair, indicating where orientation adjustments are needed.

The role and function of supports

Supports become necessary when an overhang exceeds about 45 degrees, or when bridges and internal cavities appear that cannot be self-supported.
Slicer programs offer several support-generation strategies: some build supports only from the print bed, while others also attach them to internal areas of the model.
There are even tree-like supports, which use less material and are easier to remove, although they require longer slicing times.

The surfaces where the support meets the model are typically rougher, so it is best to position the object so that these areas are not on visible sides.
Modern slicers such as Cura and PrusaSlicer allow for a support interface layer, which separates the support from the model surface, making removal easier and resulting in a smoother finish.
Additionally, using a brim or raft can improve stability, especially when there are small contact points between the support and the build plate (Feng et al., 2021).

Soluble supports and advanced techniques

In professional printing systems, soluble support materials are increasingly common, especially for complex or internal geometries.
Water-soluble PVA is ideal for PLA, BVOH dissolves faster and also works with PETG, while HIPS dissolves in limonene, making it a popular choice for ABS printing.
These materials are typically used with a separate extruder and completely disappear during post-processing, leaving even internal cavities and moving parts intact.

The main advantage of such supports is that they leave no visible marks and result in smooth, precise surfaces.
Their drawbacks are higher cost, sensitivity to moisture, and the need for dual-extruder printers for effective use (Brenken et al., 2018).

Print strength and the effect of orientation

The bond between printed layers is always weaker than the cohesion within a single layer, which makes printed parts anisotropic in strength.
When a part is subjected to tensile or shear forces, its orientation should be set so that the stress acts parallel to the layers, not between them.
For vertically loaded components, horizontal orientation can improve strength, especially when combined with thicker walls or denser perimeters.

Several studies confirm this behavior: layer orientation directly influences the mechanical properties and fracture resistance of printed parts (Sun et al., 2018).

Conclusion

Model orientation and support strategy are among the most important yet often underestimated factors in 3D printing.
A well-oriented model is not only more aesthetically pleasing and stronger, but also prints faster and uses less material.
When supports are needed, choosing the right type and material allows even the most complex geometries to be printed successfully.

Successful 3D printing is therefore not just a matter of temperature and speed, but a combination of correct orientation, a stable foundation, and smart support design.

References

• Brenken, B., Barocio, E., Favaloro, A., Kunc, V., & Pipes, R. B. (2018). Fused filament fabrication of fiber-reinforced polymers: A review. Additive Manufacturing, 21, 1–16. https://doi.org/10.1016/j.addma.2018.01.002
• Feng, Z., Wang, H., Wang, C., Sun, X., & Zhang, S. (2021).Analysis of the Influencing Factors of FDM-Supported Positions for the Compressive Strength of Printing Components Materials, 14 (14), 4008. https://doi.org/10.3390/ma14144008 
• Sun, Q., Rizvi, G. M., Bellehumeur, C. T., & Gu, P. (2018). Effect of processing conditions on the bonding quality of FDM polymer filaments. Rapid Prototyping Journal, 14(2), 72–80. https://doi.org/10.1108/13552540810862028