What are some tips and tricks to reduce the need for supports and rafts in FDM printing?

1 Choose the right orientation

One of the simplest ways to reduce the need for supports and rafts is to choose the best orientation for your model on the print bed. By rotating, tilting, or splitting your model, you can minimize the amount of overhangs and bridges that require supports. For example, you can print a cone on its side instead of its base, or print a hollow cylinder in two halves instead of as a whole. You can use your slicer software to preview the model from different angles and see how the supports and rafts are generated.

2 Adjust the overhang angle

Another way to reduce the need for supports and rafts is to adjust the overhang angle threshold in your slicer settings. The overhang angle is the angle between the horizontal plane and the surface of your model. The higher the overhang angle, the more likely the model will sag or curl without supports. By default, most slicers use a 45-degree overhang angle as the limit for generating supports. However, depending on your printer, filament, and cooling system, you may be able to increase this angle to 50, 55, or even 60 degrees, and print without supports. You can test your printer's capabilities by printing some calibration models with different overhang angles and see how they turn out.

3 Use custom supports

Sometimes, you may not be able to avoid using supports, but you can still optimize them to save material and time. One way to do this is to use custom supports instead of automatic supports. Custom supports allow you to manually place supports only where they are needed, and avoid wasting supports on areas that can print fine without them. You can also adjust the density, shape, and size of the supports to make them easier to remove and reduce the risk of damaging your model. Some slicers, such as Cura and PrusaSlicer, have built-in features for custom supports, while others may require plugins or extensions.

4 Use tree supports

Another way to optimize your supports is to use tree supports instead of linear supports. Tree supports are supports that branch out from the base and connect to the model at multiple points, like a tree. Tree supports can reduce the contact area between the supports and the model, making them easier to remove and leaving less marks. They can also save material and time by using less filament and avoiding unnecessary travel moves. Tree supports are available in some slicers, such as Cura and Meshmixer, or you can generate them using online tools, such as XYZprinting's 3D Print Hub.

5 Use soluble or breakaway supports

If you have a dual-extruder printer, you can also use soluble or breakaway supports to reduce the post-processing effort. Soluble supports are supports made from a different material than your model, such as PVA or HIPS, that can dissolve in water or another solvent. Breakaway supports are supports made from a similar material as your model, but with a lower adhesion and higher flexibility, such as eSun's eSupport. Both types of supports can be easily removed from your model without tools or force, and leave a smooth surface finish.