The walls look sparse, with gaps between the lines, or the part comes out weak with an incomplete surface. It can be all over the part or only in some areas.
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:2Flow4Max volumetric speed3Pressure advance
- 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
- If it's all over the part and started overnight, it's almost always the printer: a spool that doesn't turn freely, tangled filament, a kinked tube, dirty extruder gears or a half-clogged nozzle. Bambu recommends cleaning the nozzle before calibrating anything.
- If plastic is missing only at the corners, it's not flow: it's pressure advance. Calibrate it.
- A filament from another brand may not keep up with the speed of Bambu's profile: pick the “Generic” profile for its type, which runs slower.
Then, in the slicer (in this order)
- Nozzle temperatureFilament › FilamentIf the nozzle can't melt fast enough for the profile's speed, raise it 5 to 10 °C or lower the speed. Bambu suggests about 10 °C more for printing faster than usual.
- Max volumetric speedFilament › FilamentThe ceiling of plastic per second the printer asks of that filament. If it's higher than the filament can deliver, fast areas come out sparse: measure yours with the max flow test.
- Flow ratioFilament › FilamentIf a few tenths of plastic are missing all over the part, calibrate flow. With genuine Bambu filament, Bambu recommends keeping the factory value.
Fixed by calibrating:2Flow4Max volumetric speed3Pressure advance
Tried everything and it's still the same? Calibrate your filament with the 8 tests, or write to us with a photo.