Bridging¶

"Bridging" is a 3D printer's ability to print a straight, horizontal line across an open gap, connecting two points of a model (creating a "bridge"). Good bridging results in a straight line with little to no sagging.

How Does Bridging Work?

To create a bridge, the extruded plastic is stretched between the two points and cooled as quickly as possible so that it solidifies before it has time to droop.

Problems and Solutions¶

Problem: The bridge lines sag, look very messy and loose, or fail to connect the two points altogether.
Cause: A combination of incorrect print speed and insufficient cooling.

Solutions (in the Slicer)¶

Bridging settings are almost entirely controlled by your slicing software. Most good printing profiles already have optimized settings for bridging.

Maximize the Part Cooling Fan Speed (Bridge Fan Speed)
- Solution: This is the most important setting. Ensure that the fan speed for bridges is configured to 100%.
Adjust the Bridge Print Speed
- Solution: This may seem counterintuitive, but effective bridging often requires a relatively high print speed. The high speed helps to stretch the filament quickly between the two points. However, if the speed is too high, the line might break. It's a matter of finding the right balance. Try printing a bridging test model and adjust the speed to see what works best for your material.
Lower the Printing Temperature
- Solution: Printing at the lowest possible temperature for your filament will cause it to solidify faster, resulting in cleaner bridges with less sagging.