Blobs and zits on the surface
7 usi3d guides for “Blobs and zits on the surface”, each with the likely causes, how to check which one is yours and the step-by-step fix, with each manufacturer's official sources.
4 apply to any FDM printer and 3 are for Bambu Lab, Creality and Elegoo printers.
Each guide summarises the official documentation and says whether usi3d has already verified it on a machine.
Any FDM printer (3 guides)
- Damp TPU: strings, bubbles and a rough surface; how to dry it and print it with fewer strings
With TPU there are lots of strings and blobs between the parts of the print, the filament pops or bubbles as it leaves the nozzle, the surface is rough or full of holes…
- Wet filament: how to spot it and dry it
The filament has picked up moisture from the air: bubbles or a little smoke appear when extruding, the surface comes out rough or lumpy, there is a lot of stringing and…
- Zits, blobs and a visible seam on the walls
Small zits or bumps appear on the walls, scattered or forming a vertical line (the seam), or plastic builds up at corners and at the start or end of lines.
Materials and filament (1 guide)
- PETG: stringing, plastic stuck to the nozzle and parts that grip the plate too hard
With PETG the part has strings and blobs, plastic builds up around the nozzle and then leaves marks or gaps in the part, or the part sticks so hard to a smooth PEI plate…
Bambu Lab (1 guide)
- 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…
Creality (1 guide)
- K2 Plus: a clump or blob of filament forms around the hotend
On the K2 Plus filament builds up around the nozzle and hotend into a lump that can wrap the nozzle cover, the fans, the nozzle camera or the hotend board.
Elegoo (1 guide)
- Neptune 4 and 4 Pro: plastic blob on the hotend (blob of death) or leaks around the nozzle
During printing the filament sticks to the nozzle and the hotend surface until it forms a blob, or plastic builds up around the nozzle before starting or when stopping.
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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