Support-Free Metal 3D Printing: The Realities and Benefits

The concept of support-free printing continues to be an aspiration within the industry, but is it physically possible?

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Written by: Davy Orye, Team Manager Additive Minds Consulting, EOS GmbH

(Image courtesy of EOS.)

(Image courtesy of EOS.)

Support-free building in additive manufacturing (AM) refers to developing ways to produce 3D printed parts entirely independent of support structures. Supports are commonly used in a build to reinforce and maintain the structure of the part being created. This is necessary for various reasons, depending on the size and shape of the part being constructed.

The supports are placed strategically to prevent deformation from thermal stresses, encourage heat transfer away from the melted material and protect the forming part from possible recoater blade disruption. A recoater is the part of the machine that makes contact with and distributes the powder to create the flat surface for each layer. Supports can also provide additional rigidity to the part during the build process — for instance, attaching it to the build plate to keep it steady.

The idea of support-free printing would do away with those supports, allowing a part to be constructed entirely free-standing and ready to go as soon as the print is completed.

Advantages and Disadvantages of 3D Printing with Supports

Supports essentially function as small, raised build platforms under the part being made – providing additional build structure. In some circumstances, without the right support, a part will fail to fully form, most commonly caused by an application’s overhang section or where a part needs a hole through it. Either of these scenarios will only progress so far before they’re unable to anchor themselves during the build process. As a general rule, supports tend to be required for any aspect of a build that extends under 45-degrees from the build platform — this means any part that elevates at an acute angle.

While using build supports is still a requirement for many complex applications, they come at the cost of materials, print times and additional post-processing steps.

Drawback 1: Print Times

Each of the supports needs to be progressively printed with each layer of the build, in the same way that the part itself is created layer by layer. This results in longer print times that reduce efficiency and use more energy, impacting the cost of builds in several ways.

Drawback 2: Material Consumption

As the supports are constructed in the same way as the rest of the part being built, it means that extra material is used to create them. The supports are removed from the final product in post-processing and disposed of as waste material, which affects time and costs.

Drawback 3: Post-Processing

Most 3D printed parts go through a post-processing stage, which can consist of several steps depending on what’s required to finish the part. Building with bigger and more supports requires a longer, more intensive finishing process compared to those without supports. This time-consuming process is not only manually demanding, but it also comes at an additional cost.

There are also instances where some supports are inaccessible and therefore cannot be removed – for instance, inside an application. While these may not prevent the part from functioning, they will add weight and potentially impact the overall performance of the part.

Impeller with traditional support structure in blue and advanced design of this impeller with no supports resulting in 15 percent less material. (Image courtesy of EOS.)

Impeller with traditional support structure in blue and advanced design of this impeller with no supports resulting in 15 percent less material. (Image courtesy of EOS.)

The Benefits of Support-Free Building

By shifting to support-free 3D printing, the AM process can be improved economically, environmentally and by decreasing production time. Little to no supports means less of the material in the powder bed will be melted, which has multiple benefits for your business.

Cut Your Production Time: 

If the lasers in the printer don’t need to continually add layers to the supports, the build time is reduced with the removal of each support. If each small time reduction is compounded for large scale production, companies can cut down significantly on production times.

Save Post-Processing Resources: 

Not having supports in the first place would mean their removal could be completely eradicated from the post-process phase, positively impacting lead times. A large amount of the time spent in post-processing is focused on the removal of supports because their removal includes time-intensive surface treatments afterwards. A support-free build would do away with such intensive post-process adjustments, making it quicker and cheaper to complete a part.

Reduce Material Use and Your Environmental Impact: 

With sustainability and responsible manufacturing in mind, it’s clear that not using supports—or even reducing them in size and number—will mean less material waste. This results in reduced energy expenditure as well, cutting down on both the financial and environmental cost of 3D printing.

What’s Possible in Support-Free 3D Printing?

The reality is that 100 percent support-free AM currently isn’t possible for every application or geometry. That isn’t to say that it may not be in the future. At EOS Additive Minds, we’ve recently made some incredible leaps in getting closer to that end goal of support-free printing.

Impeller build using an optimized process on an EOS M 290 with no internal supports and a 35 percent cost reduction. (Image courtesy of EOS.)

Impeller build using an optimized process on an EOS M 290 with no internal supports and a 35 percent cost reduction. (Image courtesy of EOS.)

Probably the most sustained limitation of metal AM is that you cannot print below a certain overhang angle without supports. Without supports, the overhang is at risk of warping due to the residual stresses caused by exposure during the print, putting limitations on the users of metal AM systems.

Thanks to the innovative thinking of industry leaders, the critical 45-degree angle is now being questioned and challenged. Many software and parameter packages have now become available that enable users to print overhangs and bridges at much lower angles without compromising the quality of the part.

Take a look at our case study on shrouded impellers, where a support-free build was achieved despite pushing the limits of overhang angles.

This particular project also saw the complete elimination of internal supports, which makes the post-processing procedure much less complicated and reduced the overall production cost by 35 percent.

The process development team has taken the findings from innovative projects like this and applied them to the standard processes that are available for “plug and play” 3D printing software. This means that even without an expert consultant, you can reduce angle limits to 20 degrees as standard.

To learn more, visit EOS.


About the Author

Davy Orye is the Team Manager at Additive Minds Consulting, a division of EOS GmbH.