Don't know what your fault is called? That doesn't matter. This catalogue covers the 27 most common problems in 3D printing and is organised by what you see on the print, not by terminology. Read through the descriptions, find the one that matches the model in front of you, and click the name of the problem.
Every entry leads to a separate page with a full list of causes and specific fixes — with slicer settings and temperatures for Porima materials. The most common 3D printing faults rarely have a single cause, which is why the causes on each destination page are ordered from the most likely to the rarest. We have split the faults into four groups matching the way a failure actually feels at the printer: something never took hold at the start, the print finished but looks wrong, the print failed outright, or the filament itself and the conditions in the room are to blame.
First layer problems
The first two minutes of a print decide the rest of it. If the material does not bond to the bed, no later setting will repair that.
The lines do not hold onto the bed, they curl up behind the nozzle or lift at the corners right after being laid down.
The corners of the print rise upwards and the underside stops sitting flat against the plate during the print.
The bottom few layers are noticeably wider than the rest of the model, as if the print had been squashed against the bed.
The printer moves across the bed, but for the first half a minute or so nothing comes out of the nozzle.
Once cooled, the model grips the plate so hard that you cannot lift it off without a scraper and real force.
The print looks wrong
The print ran to the end, the model is in one piece, but the surface, the dimensions or the detail are not what they should be. This is the largest group and usually the easiest to put right.
The model is covered in thin cobweb-like strands running between its parts.
The walls are thin and full of holes, gaps show between neighbouring lines, and the layers look only partly filled.
The walls are rippled and thicker than they should be, and excess plastic gathers along the edges.
After every corner and after every embossed letter the surface repeats a rippling that slowly fades out.
The top surface is rough and has openings through which you can see the infill inside the model.
On a smooth wall, at the same spot on every layer, a small blob or raised dot keeps repeating.
Brown streaks and dark patches appear on the print, and the material looks burnt.
Lines stretched across an open space sag, ripple or snap halfway across the span.
Where the supports were, the surface is ragged and covered in marks, and the supports themselves are hard to break off.
In narrow parts of the model an empty slot is left between the lines, and light passes straight through it.
The printed part does not match the model: holes come out too small and pegs too thick.
The print failed
The print was interrupted or came out fit only for the bin. Here the cause usually lies in the mechanics, in the filament's path to the nozzle, or in the nozzle itself.
The print cracks along the layer lines and can be pulled apart into pieces with your fingers.
From a certain height the whole model is offset sideways and the upper layers no longer line up with the lower ones.
The extruder is running and clicking, but nothing comes out of the nozzle, or only a thin curling strand.
The filament has stopped on its way to the nozzle and cannot be pulled back or pushed through by hand.
You can see a worn, flattened patch on the filament in the feeder, and the drive wheel is spinning in plastic dust.
The start of the print is fine, but after a few hours the head is moving through the air with no material.
The infill inside the model is sparse and ragged, and its lines do not join up with the walls.
Filament and surroundings
The fourth group covers problems that are invisible in the slicer. Before you start changing settings, check whether the cause lies in the spool or in the room.
The nozzle crackles and hisses while printing, and the surface comes out matte and rough.
The filament has wedged under its own coil and the spool stops unwinding mid-print.
There is a strong chemical smell in the room, and after a longer print you get a headache.
The filament cracks when bent and breaks in the feeder or right next to the spool.
Before you start changing settings
Four rules apply to every one of the 27 problems on this list. Ignoring them is the most common reason a repair takes a week instead of a single evening.
Four rules of diagnosis
- Change one parameter at a time. After each change, print the same test. If you alter temperature, retraction and speed all at once, you will never learn which one helped, and with the next spool you will be starting from scratch.
- Measure instead of guessing. A pair of callipers settles things faster than a forum. Measure the wall width, the filament diameter at several points, the real height of the model. Calibrate flow and extruder steps before you decide the plastic is at fault.
- When a material that used to print without trouble suddenly starts causing problems, suspect moisture first. An open spool of PETG, TPU or nylon absorbs water within a few days. Dry it and repeat the same print before you change anything in the slicer: drying filament — temperature and time for every material.
- Check that your temperature sits inside the manufacturer's range. Half the faults on this list come down to running outside the range given for that material. We have collected the nozzle and bed ranges for every Porima material in one place: print temperature table.
Which materials cause the most trouble
Some problems come not from the printer but from the choice of material. The table below shows what to expect from each family of plastics before you order a spool.
| Material family | Print difficulty | Main risk |
|---|---|---|
| PLA and PLA variants | Very easy | The least demanding material, prints on an open printer. Nozzle 200–230 °C, bed 0–60 °C. The limit is the finished part's temperature resistance — 60 °C according to the manufacturer's label. |
| PETG | Easy | Stringing tendency rated as high by the manufacturer. Nozzle 240–260 °C, bed 60–80 °C. Absorbs moisture faster than PLA. |
| ABS and ASA | Difficult | High tendency to warp and a strong smell. The manufacturer requires an enclosed chamber at 50 °C. Bed 80–110 °C (ABS) and 90–120 °C (ASA). |
| PA (nylon) | Very difficult | Low moisture resistance — drying for 8–12 h at 65–80 °C is mandatory. Requires an enclosed, heated chamber. Nozzle 260–290 °C, bed 90–120 °C. |
| TPU Flex 98A | Difficult | A flexible material: a direct drive extruder and low print speed are recommended. Nozzle 230–260 °C, bed 40–60 °C. |
| PLA/CF | Medium | Very highly abrasive — a hardened nozzle is mandatory. It prints almost as easily as PLA, but detail below 0.4 mm will not come out. Nozzle 220–250 °C, bed 50–70 °C. |
Source: the official FDM technical data table from the manufacturer, Porima. The full set of 25 materials, together with cooling and drying: print temperature table.
Filament with a repeatable diameter is half the fix. Porima filaments are produced to a ±0.03 mm diameter tolerance, and we publish the manufacturer's full official print data — you don't have to guess it. Our warehouse is near Poznań, in Swarzędz.
See Porima filaments · print temperature table · Drying filament