Layer height: Does it really matter for a 3D part?

Layer height may be considered as one of the most trivial of the 3D printer settings. However, it often plays a huge role in the entire 3D printing process.

3D parts are built in an additive nature (printed layer by layer). Thus, the thickness of each layer may determine the surface quality, resolution and printing time of the 3D part.

This only means that the layer height has something to do with the most important aspects in a 3D part. Read on below to learn more about the layer height and how it affects the 3D part.

Details about layer height

Layer height is the exact height of each layer of material that is cured, extruded or sintered by a 3D printer. The layer height setting can be adjusted through a slicer program. Layer height should be set up properly because it will also affect the print’s speed, smoothness and resolution.

Layer height is usually measured in microns. One micron (µm) is equivalent to 0.001mm. The standard smallest height is generally between 50 and 100 microns (0.05 and 0.1 mm).  

Why is layer height important

For 3D printing processes such as SLS, Material Jetting or SLM/DMLS, assigning a layer height is not necessary. This is because the layer height is already pre-set by the machine manufacturer.

When it comes to FDM and SLA, the layer height is an important design parameter that needs to be considered. An inappropriate layer height can affect the printing time, cost, visual appearance and physical properties of a 3D part.

There is a small difference in the appearance between 3D parts that are printed at 100 µm and 200 µm. However, the printing time for 3D part at 100 µm will take twice as long to print. This is because the 3D printer will have to trace many cross-sections of the 3D part.

Reasons for changing the layer height

Below are a few reasons why designers change or modify the layer height. Read on below to learn more.

• Optimizing the print speed

Changing the layer height will also increase the printing speed. If there is a larger layer height, this means that the 3D printer doesn’t have to print many layers to achieve the same total height. This will result in a much faster print.

Nevertheless, increasing the layer height will also decrease the 3D part’s resolution and quality. Increasing the layer height is applicable for larger prints where some close-up details will be either overlooked or touched up during post-processing.

• Enhancing the resolution

Lower layer height will cause the 3D printer to slow down its speed. Thus, the printer will also put down more layers for a given height. This will also allow the 3D part to have a much higher detail and resolution.

• Smoothing the surface

With a lower layer height, each layer will become less obvious. This will also make the print smoother. As to larger layer height, the layers are clearly visible and the surface of the print becomes rough.

With this knowledge in mind, printing with 3D part that requires very smooth surface finish such as axles can be possible by just reducing the layer height.

Choosing the appropriate layer height

Different 3D printers have different maximum resolutions for layer height. Below is the standard layer height for the most common 3D printing processes.

• FDM: 50 - 400 µm (frequently used: 200 µm)
• SLA/DLP: 25 - 100 µm (frequently used: 50 µm)
• SLS: 80 - 120 µm (frequently used: 100 µm)
• Material Jetting: 16 - 30 µm (frequently used: 16 µm)
• Binder Jetting: 100 µm
• DMLS/SLM: 30 - 50 µm

Important reminders when choosing layer height

• For setting the layer height on FDM printers, a shorter vertical layer will result in thicker horizontal line. While a taller vertical layer results in a thinner horizontal line.
• It is important to determine beforehand whether visual appearance (a smoother surface) or time and cost savings are more important. You can select a lower layer height if visual appearance is more important to you. Lower layer height is also recommended for parts with curved surfaces. On the contrary, having higher layer height is a good choice if you want a faster and more cost-effective printing.
• When deciding the layer height, it is also crucial to consider if the 3D part will be post-processed. If the 3D part is going to be sanded, smoothed or painted, then a higher layer height may be the best choice.

Conclusion

Layer height may be considered as a not-so-important 3D printer settings. However, when used right, it can greatly impact the entire 3D printing process and the outcome.

Prior to printing, the 3d designer should also determine ahead of time whether visual appearance or functionality is their main concern. In that way, they can decide what will be the layer height for a specific 3D part. 

If you have any concerns regarding layer height or 3D printing, in general, leaving it to the professionals may be the best thing to do. You can ask a local 3D printing service provider to help you with your 3D printing needs. They can offer services such as 3D design modelling services, custom 3D printing, industrial 3D printing and many more.