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Like everything else on Earth, 3D printing is constrained by gravity. 3D printers don’t print well over thin air, despite their amazing capacity to transform plastic spools into action figures, enormous swords, and other entertaining models.
Slicer software can add a variety of 3D printed supports to hold up your model as it publishes to solve this issue. Those supports can be removed after printing everything, but they might leave a mark on your part’s surface.
In this article, we’ll go over the three key steps to determine whether and how to add 3D printing supports to your model. Although similar settings will be available in most slicers, we’ll use Cura slicer settings as an example to examine the options. Let’s start now!
When creating a model, it’s essential to remember that not every 3D print needs support. Knowing how to avoid supports is crucial because they increase waste and can impact the surface of your printed part.
Step 1: When to Use 3D Printing Supports
How do you determine whether your model needs 3D printing supports? Take these actions:
- Bridges or overhangs are parts of a print that require the 3D printer to print partially or entirely over the air, such as the vertically printed arms of a T or Y. In contrast, bridges are overhangs joined to the model at both ends, like the middle of an “H.” The standard method for measuring overhangs and bridges is to measure the angle from the Z-axis above the overhang. For instance, the overhang on the letter T is 90 degrees, whereas the overhang on the letter Y is 45 degrees. You probably need supports if your model has severe overhangs (above 60°). Supports are always required for overhangs greater than 90 degrees, such as the lowercase ‘r”s arch.
- Performance of the printer: Not every 3D printer is created equal. To see how well your printer performs, try printing an overhang test. You should turn on supports for models with similar overhangs if a 60-degree overhang doesn’t look good.
- Slow print rate: Generally, prints with a slower print rate are of higher quality. But that’s not always the case with 3D printing supports. The quality of overhangs, and especially bridges, improve with print speed. You might need to enable supports for a lower overhang angle when printing slowly instead of when printing more quickly.
Avoiding 3D Printing Supports
Prevention is always preferable to cure, as they say. Here are some general pointers to prevent printing with supports:
- Orient the 3D object correctly: Let’s take printing the letter T as an example. We also have to 3D print supports if we try to print it upright. However, suppose we simply rotate the model so that the top bar is flat on the print bed. In that case, we can eliminate the need for support, saving time and material. Ensure your model is oriented optimally to reduce the need for 3D printed supports.
- Reduce overhang angles: If you built the model yourself, you might want to reduce the overhang angles. Sharp angles can be rounded off with files and chamfers, significantly improving the quality of the overhang produced by 3D printing.
- Think about dividing the model into two parts: A sphere is one of the most challenging shapes to 3D print. Because, even with supports, the enormous overhangs near the bottom often produce unattractive results. In this situation, printing the sphere’s two halves separately and then gluing them together to create a stunning, support-free finish is much simpler.
- Design for 3D printing: It can be beneficial to modify a model’s design to accommodate 3D printing if you have access to a CAD or 3D modeling tool.
Step 2: Choosing a Support Type
If you’re sure you require 3D printing support, all you have to do in Cura (or your preferred slicer) is check the “Generate Support” box and move on. However, there are so many ways to 3D print supports that it might be worthwhile to examine the settings further.
The most popular kind of support is lattice supports. Because they are simple to alter, quick to produce, and suitable for most 3D models, they are widely used. The drawback is that improperly printed supports may leave marks on the final model and be challenging to remove. In general, use lattice supports for flat, angular, or highly steep overhangs.
If the “Support Pattern” option in Cura’s Support menu isn’t visible, change your settings visibility to “Advanced” or higher. Next, choose your preferred support pattern using the dropdown. To see what it appears like, switch between the X-Ray view and Layer view in the preview. Zig Zag is Cura’s default support type, which makes sense, given how simple it is to print and remove. But underneath, seven support patterns are available (some of which are pictured above). Make sure the support pattern you choose complements the shape of your model. For parts with circular overhangs (like a sphere), which aren’t uniformly supported by a grid, concentrative, for instance, is helpful.
Nearly everything that tree-type support is what it sounds like. Supports made of trees work best for organic shapes like people and animals. As a print’s height rises, they begin as “trunks” near the bottom and branch out to support overhangs in the model.
These supports can be 3D printed for less money and faster print times. Choose “Tree Support” from Cura’s “Support Structure” dropdown. Before clicking “Slice,” ensure your model is correctly positioned and oriented. It can take a while to generate.
Tree-type supports typically offer a cleaner surface finish because they don’t touch the model much. However, because the trees are generated dynamically, they can be difficult to slice. Choose these supports if your model has many organic shapes or small, gentle (less than 60°) overhangs. As they are made to touch the model at fewer points, these supports are less useful for large, flat overhangs like a roof.
This is a specialized, premium substitute for supports printed from the same material as the model. For instance, a dual extruder printer can print a model in PLA with one nozzle. While printing all the support material with a water-soluble filament (commonly PVA) with the other nozzle. After the 3D print is complete, simply immerse the print in some water to cause the supports to disintegrate, leaving a clean model in its place. What a cool thing! We wholeheartedly endorse this choice if you’re fortunate enough to have a dual extruder printer and don’t mind shelling out for some slightly pricy filament. Learn more by reading this comprehensive manual.
Step 3: Setting the 3D Printing Supports Density
Choosing the ideal support density for 3D printing comes next. We advise starting with a density of roughly 10% and modifying it as needed. Select “Layer view” in the Preview tab and make sure “Helpers” is checked in the color scheme to see your sliced supports in Cura. The following are some elements that influence support density:
- Print speed: The faster you print, the less dense your supports need to be to get a good-quality finish.
- Desired print quality: Increased density can result in overhangs of higher quality (at the cost of print time). However, removing the support may occasionally harm the print if it is too high.
- Size of overhang: You need denser supports as the overhang increases in angle. It is advised to use a support density of at least 15%, especially for 90-degree overhangs.
- Support removal: The harder it is to remove the supports, the denser they are (and the more material you waste).
Advanced 3D Printing Supports Settings of Cura
You can play around with many other Cura settings to fine-tune your print. Even though you might never need to change these settings, it’s still a good idea to be aware that they exist.
- Support Placement: Cura allows you to select whether supports should be generated everywhere (including on the model) or just from the build plate (i.e., only those supports that would touch the bed).
- Support Overhang Angle: Cura will generate supports with a minimum overhang angle of this value. (This defaults to 45°.) If your printer can handle temperatures up to 70°, changing this setting regularly helps save filament and support removal work.
- Support Z Distance: This space separates the top layer of the support from the model’s first layer. One layer’s height is a good starting point. Consider raising this value a little if you discover that your supports are too glued to the model. A small amount of room is required so that 3D printing supports can be removed without difficulty and without melting into the model.
- Gradual Support Infill Steps: You can use a clever little feature in Cura to decrease the print time and material usage. Cura will print those extremely tall and dense supports with a lower density at the bottom and a higher density near the model, which is where you need it. The number of times the slicer will divide the support density in half, starting at the top, is controlled by this setting.