¶ Bad overhang quality
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:
¶ Solutions
When poor overhang occurs, 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 model's overhang angle referred to here is the angle formed between the plane of the inclined part of the model and a line perpendicular to the heatbed surface. In contrast, the overhang threshold in the overhang speed refers to the proportion of the extruded lines that are unsupported by the lower layer within the width of the extrusion line; these two concepts are not the same.
¶ The model's overhang angle is greater than 45°
If the model's overhang angle exceeds 45 degrees, it is recommended to refer to the image below and add supports to improve print quality. For more information on support settings, you can refer to this wiki: Support | Bambu Lab Wiki.
¶ The model's overhang angle is less than 45°
If the model's overhang angle is less than 45°, it is recommended to consider the following methods to adjust parameters for improving print quality.
1. Reduce the nozzle temperature appropriately. Lowering the nozzle temperature can help reduce the need for cooling when the print speed of the overhanging part is slower.
- For official filaments, you can refer to this wiki: Filament guide - Compatibility to printer, nozzle, AMS, build plate, glue and required parametes | Bambu Lab Wiki. Ensure that the temperature remains within the recommended range, and consider reducing the nozzle temperature by 5-10°C.
- For third-party filaments, it is recommended to test and determine the optimal printing temperature by printing a temperature tower. For the tutorial on printing a temperature tower, please refer to this wiki: Calibration for 3rd Party Printer | Bambu Lab Wiki.
2. Reduce the print speed appropriately, or enable "Slow down for overhang", and further reduce the overhang speed if necessary. If necessary, you can further reduce the overhang speed. The overhang speed is typically set between 10-60 mm/s. A larger overhang threshold will increase the extent of the overhang part, and it usually requires using a lower speed to ensure print quality. For detailed information on overhang speed reduction, please refer to this wiki: Slow Down for Overhangs | Bambu Lab Wiki.
3. Increase the speed percentage of the Auxiliary Part Cooling Fan and Cooling Fan for Hotend appropriately. If the overhang quality is consistently poor, please check if the Cooling Fan for Hotend and Auxiliary Part Cooling Fan works properly during the printing process. This can be tested by switching and adjusting the fan speed percentage in the slicer in Bambu Studio.
5. Open the front door and the top glass cover of the printer for better heat dissipation. (This is generally only applicable to PLA, PETG, and TPU filaments. Operating in this way for other filaments may cause warping and weaker layer adhesion due to excessively low chamber temperature.)