Too little filament (under-extrusion)
12 usi3d guides for “Too little filament (under-extrusion)”, each with the likely causes, how to check which one is yours and the step-by-step fix, with each manufacturer's official sources.
5 apply to any FDM printer and 7 are for Anycubic, Bambu Lab, Elegoo, Flashforge, Sovol and UltiMaker printers.
Each guide summarises the official documentation and says whether usi3d has already verified it on a machine.
Any FDM printer (4 guides)
- Gaps in the top surface, in the walls or between infill and perimeters
The top surface has holes, separated lines or bulges (the infill shows through), gaps appear between perimeters or between the walls and the infill, or holes appear on…
- High-speed PLA: which temperature and flow to use so it does not come out with gaps or weak layers
With a high-speed PLA (those sold for printing at several hundred mm/s), the part comes out with gaps, walls thinner than intended or layers that split easily, the shine…
- Not enough plastic: gaps and thin walls (under-extrusion)
Material is missing from the part: thin or separated lines, gaps between perimeters, incomplete layers or porous top surfaces.
- The extruder clicks or skips
You hear a click, knock or snap from the extruder and sometimes the filament moves back a little.
Materials and filament (1 guide)
- Carbon or glass fibre filaments: they wear the nozzle, clog or snap
With PLA-CF, PETG-CF, PA-CF or other fibre-filled filaments (also glow-in-the-dark or wood ones), less and less material comes out as the nozzle wears, the nozzle clogs…
Anycubic (1 guide)
- Kobra S1: little or no filament comes out (hotend clog or error 11518)
On the Kobra S1 the extruder motor turns but little or no filament comes out, the extruder clicks, or the extruded line is thinner than normal and the walls have gaps.
Bambu Lab (2 guides)
- A1 and A1 mini: not extruding or under-extruding (clogged nozzle, slipping extruder or nozzle too low)
The A1 or A1 mini extrudes no filament or too little: the first layer comes out with almost no plastic, the extruder gear clicks and skips, or it turns but nothing comes…
- Flow dynamics (K factor) and flow rate calibration in Bambu Studio: when to run it and why it fails
Corners come out rounded or bulging, lines are missing or overlapping, the top surface is rough or blobby, or automatic flow dynamics calibration returns an odd value or…
Elegoo (1 guide)
- Centauri Carbon 2: no filament coming out, clogged nozzle or errors 1243, 1263 or 1264
The Centauri Carbon 2 does not extrude or under-extrudes, or stops with error 1243 (extrusion failed at the toolhead: check whether it is clogged) or with 1263 or 1264…
Flashforge (1 guide)
- Adventurer 5M, 5M Pro or AD5X: no filament comes out, too little comes out or the nozzle is clogged
The printer does not extrude when loading or starting a print, too little plastic comes out (parts with missing material or fuzz), or the extruder creaks when loading by…
Sovol (1 guide)
- SV06: clogs mid-print or under-extrudes (bi-metal heat break, retraction and gear)
On the SV06 the print fails at a random height because filament stops coming out, or too little plastic comes out and the part has gaps.
UltiMaker (1 guide)
- UltiMaker S: print core not recognised, incompatible or clogged, or the feeder grinds the filament
The UltiMaker S reports that it does not recognise a print core or that it is not compatible with the loaded material; or material does not flow consistently (gaps, thin…
Products that may help
Products from the usi3d shop that fit these guides, chosen for the fit and not for the commission. Check that they work with your printer before buying.
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