Overhangs (the parts that stick out with nothing below) bend, curl or come out rough on the underside.
It happens on any FDM printer. Setting names are Bambu Studio's: in Orca Slicer almost all have the same name, and PrusaSlicer or Cura usually have an equivalent.
Where do I start?
Two questions to sort out what to check. It's a guide, not a sure fix: every printer and every filament is different.
Check in this order
- The printerIf it printed fine yesterday and not today, it's almost never the profile. Check the plate, the nozzle and the room: printing at 15 °C is not the same as at 30 °C.
- The filamentA spool that has soaked up moisture gives strings, bubbles and brittle parts. Dry it before changing settings, and pick that filament's profile in the program.Filament pages
- The quick checksThe “First” list below: it's the fastest to check.Go to “First”
- The slicerOnly now, the settings below, in order. Change one thing, print a small test and compare. If you change three at once and it gets fixed, you won't know which one did it.Go to the settings
Check in this order
- The quick checksThe “First” list below: it's the fastest to check.Go to “First”
- The filamentA spool that has soaked up moisture gives strings, bubbles and brittle parts. Dry it before changing settings, and pick that filament's profile in the program.Filament pages
- The testsCalibrate your filament with these tests:7Overhangs and bridges1Temperature
- The slicerOnly now, the settings below, in order. Change one thing, print a small test and compare. If you change three at once and it gets fixed, you won't know which one did it.Go to the settings
Check in this order
- The quick checksThe “First” list below: it's the fastest to check.Go to “First”
- The previewStep through the slicer preview layer by layer: that's where you spot missing supports and odd areas in this part.
- The slicerOnly now, the settings below, in order. Change one thing, print a small test and compare. If you change three at once and it gets fixed, you won't know which one did it.Go to the settings
First
Then, in the slicer (in this order)
- Threshold angleProcess › SupportIf sloped faces come out ugly, raise the angle (35–40°) so they get support too.
- Slow down for overhangProcess › SpeedSlows down only what overhangs. Leave it on.
- Fan speed for overhangsFilament › CoolingThe fan goes up to this speed on what overhangs (PLA Basic: 100%), so it hardens before it sags.
- Nozzle temperatureFilament › FilamentA few degrees cooler, the plastic hardens before it droops. Lower it 5 °C at a time; for PLA, Bambu suggests going down to about 205 °C with the overhang fan at 100%.
- Support typeProcess › SupportFor figures, tree. If auto doesn't put support where you want it, paint it.
Fixed by calibrating:7Overhangs and bridges1Temperature
Tried everything and it's still the same? Calibrate your filament with the 8 tests, or write to us with a photo.