ExtrudoWhy is my 3D print sagging overhangs and bridges?
Sagging overhangs and bridges is usually caused by the plastic isn't cooling fast enough before the next layer is printed on top of it. Overhanging parts droop, sag, or look messy instead of staying crisp and flat
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Quick reference
| Defect | Most likely cause | First thing to try |
|---|---|---|
| Sagging overhangs and bridges | The plastic isn't cooling fast enough before the next layer is printed on top of it | Increase cooling fan speed |
What it looks like
Overhanging parts droop, sag, or look messy instead of staying crisp and flat
Most likely cause
The plastic isn't cooling fast enough before the next layer is printed on top of it
How do I fix sagging overhangs and bridges? Step-by-step
- 1
Increase cooling fan speed
Turn your part cooling fan up to 100% for overhangs and bridges specifically.
Done when: Overhang surface looks firmer and less droopy
- 2
Slow down for overhangs
In your slicer, reduce the print speed specifically for overhang and bridge areas.
Done when: Bridges span cleanly without sagging in the middle
- 3
Add supports for steep angles
If the overhang is steeper than about 45 degrees from vertical, add supports underneath it.
Done when: Supports are visible under the steepest overhangs in the print preview
Frequently asked
What causes sagging overhangs and bridges in 3D prints?
The plastic isn't cooling fast enough before the next layer is printed on top of it
How do I fix sagging overhangs and bridges on my printer?
Follow the step-by-step fix above, starting with "Increase cooling fan speed". Each step includes a "done when" check so you know whether it worked before moving on.
Is this fix confirmed by other makers?
This entry is part of Extrudo's seeded defect library. Confirmation counts appear once real users report the fix worked.
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