¶ What is an Overhang?
When part of a model extends outward without solid material beneath to support it, this portion is considered an overhang. Since FDM 3D printing builds objects layer by layer, material without support beneath tends to sag or deform due to gravity.
During printing, supports act like a safety net beneath overhangs, providing stability for the upper layers.
¶ Common Types of Overhangs
Overhangs usually refer to inclined surfaces or unsupported features of a model in the vertical direction, as shown below. Both cases are considered typical overhang structures.
¶ Causes of Overhang Print Failures
Cause: When printing the overhanging surface, the extruded filament is not cooled in time and bonds to the specified position, resulting in dropping, which is usually shown as follows:
Left: poor overhang quality; Right: Good overhang quality
¶ Solutions
In 3D printing, Self-supporting Overhang refers to an overhang structure that can be formed without the need for additional supports, relying solely on its own geometry or layer-by-layer stacking to maintain stability.
Such overhangs take advantage of the self-supporting characteristics of the material during layer deposition, preventing significant collapse or deformation.
When Excessive Overhang occurs — for example, when the nozzle is required to print outward into free space beyond a certain angle without adequate support — we recommend that you try the following methods to improve it:
First, observe the overhang tilt angle of the model to determine whether it is too large.
Generally, when the overhang tilt angle is greater than 45°, it is recommended to add supports; when it is less than 45°, no support is needed. You can try to optimize the parameters according to the subsequent steps to improve the overhang quality.
Note: The overhang angle mentioned here refers to the angle formed between the inclined surface of the model and the line perpendicular to the heatbed surface. In contrast, the overhang threshold in overhang slowdown refers to the proportion of unsupported extrusion width within an extrusion line, which is not the same concept. The illustration below shows a comparison of support generation in Bambu Studio when the overhang threshold angle is set to 5° and 85°. The larger the input angle, the more supports will be generated.
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¶ Enable Supports
If the model’s overhang angle is too steep（more than 45°）, it is recommended to enable supports in Bambu Studio to improve print quality. For more details on support settings, please refer to the Guide to Support Materials and Functions.
¶ Lower Nozzle Temperature
If the model’s overhang angle is not large (e.g., less than 45°), you can try slightly lowering the nozzle temperature.
When the printing speed for overhang areas is relatively slow, lowering the nozzle temperature helps reduce the need for cooling.
- For PLA, you can lower the other layers’ nozzle temperature to around 205 °C, while increasing the overhang cooling fan speed to 100%.
- For other official filaments, you can check the Filament Guide for compatibility and recommended parameters across printer models, nozzles, AMS, build plates, and adhesives. Make sure the temperature stays within the recommended range, and lower it by about 5–10 °C if needed.
- For third-party filaments, it’s recommended to print a temperature tower to determine the optimal temperature. For instructions, see the Third-Party Filament Calibration Guide.
¶ Enable Overhang Slowing
Reduce the overall print speed, or enable Overhang Slowing to decrease print speed specifically for overhang regions. If necessary, you can further lower the overhang speed. Overhang speeds are generally set between 10–60 mm/s. The larger the overhang threshold, the greater the unsupported area—typically requiring slower speeds to ensure quality. For more details, see the Overhang Slowing Guide.
¶ Increase Cooling Fan Speed
Increase the percentage of the part cooling fan and auxiliary cooling fan as needed. If overhang quality remains poor, check whether the part cooling fan and auxiliary cooling fan are working properly during printing. You can toggle them on/off and adjust fan speed percentages in Bambu Studio (example shown with H2D below).
¶ Improve Heat Dissipation
Opening the printer’s front door and glass lid can improve cooling performance (recommended only for materials like PLA, PETG, TPU. For high-temperature filaments, this may cause warping or poor layer adhesion due to low chamber temperatures).
¶ Print Quality Comparison
Below is a comparison of models printed before and after parameter adjustments.
¶ End Notes
We hope the detailed guide provided has been helpful and informative.
If this guide does not solve your problem, please submit a technical ticket, we will answer your questions and provide assistance.
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