Why Your 3D Prints Keep Failing: Warping, Stringing, and More — Fixed

Your print failed. Again. And it failed differently than last time, which is somehow more frustrating.

I spent most of my first three months as a 3D printing beginner in this exact loop: fix one problem, discover another, change three settings at once trying to fix it, and have no idea which change helped and which made things worse. I learned the hard way that troubleshooting 3D printing problems requires changing one variable at a time and understanding what each setting actually does.

This guide covers the six most common print failures — warping, stringing, layer delamination, under-extrusion, over-extrusion, and elephant foot — with the specific settings and numbers that fix each one. I also included a diagnostic flowchart at the end so you can identify what you are looking at when something goes wrong.

Affiliate Disclosure: Some links in this article are affiliate links. If you purchase through one of them, I earn a small commission at no extra cost to you. I only link to products I personally use and recommend.

Before You Troubleshoot: Dry Your Filament

I cannot say this enough. Before you blame your printer settings, dry your filament.

Moisture is the silent killer of 3D print quality. PLA absorbs moisture from the air within 1-3 weeks in a humid environment. PETG absorbs moisture even faster. When wet filament hits the hot nozzle, the moisture vaporizes and causes:

Visible bubbles and craters in the surface
Popping and crackling sounds during printing (you can hear it — it sounds like someone slowly walking on bubble wrap)
Significant stringing even with good retraction settings
Inconsistent extrusion width that mimics a partial clog
Failed prints that look like under-extrusion or over-extrusion but do not respond to those fixes

If your prints looked fine two weeks ago and have gotten progressively worse without any settings changes: it is almost certainly moisture.

The fix: Run your filament in a filament dryer at 45°C for 4-6 hours for PLA, 55-65°C for PETG and nylon, 65-70°C for ABS. I use a SUNLU S2 ($40) — Check price on Amazon. After drying, store filament in sealed zip-lock bags with desiccant packets until use.

The Polymaker PolyDryer ($50-60) — Check price on Amazon — is the premium option that doubles as a filament spool holder, drying your filament while you print. Worth it if you live somewhere humid (anywhere with summers above 70% relative humidity).

Failure 1: Warping

What it looks like: The corners or edges of your print curl up off the build plate during or after printing. On severe warp, the print may detach entirely mid-print and you come back to spaghetti.

Why it happens: As plastic cools and contracts, it pulls inward. If the first few layers cool too fast — or if there is a temperature gradient between the bottom layers and the ambient air — the cooler layers contract more than the layers still attached to the warm bed. The result is edges that curl upward.

Warping is most severe with ABS (high contraction coefficient) and large, flat prints with big surface areas. Small prints, rounded forms, and PLA warp much less.

Fix 1: Bed Temperature and First Layer Speed

Your bed temperature directly affects how well the first layer bonds and how slowly the bottom layers cool.

PLA: 55-65°C bed. If you are seeing warp on PLA at 55°C, raise to 60°C. Do not go above 65°C for standard PLA — the layers above the bed will start to soften.
PETG: 70-85°C bed. Start at 75°C and adjust.
ABS: 100-110°C bed. ABS also needs a fully enclosed chamber — open-frame printing ABS will almost always warp regardless of bed temperature.
ASA: 100-110°C bed, same enclosure requirement as ABS.

Also slow down your first layer. My standard first layer speed is 25-35mm/s regardless of the overall print speed. A slower first layer gives the material more time to bond to the plate and reduces the impact of any slight inaccuracies in nozzle height.

Fix 2: Build Plate Cleanliness

I have tested this extensively and it is consistently underestimated: a clean build plate prevents more warping than temperature tweaks.

Fingerprint oils are invisible and reduce adhesion dramatically. The moment you touch the build plate surface with your bare fingers, that print site loses significant grip. Wipe your plate with 99% isopropyl alcohol and a clean microfiber cloth before every print session, not when it looks dirty. By the time you can see residue, you have already lost adhesion on multiple prints.

If the textured PEI coating has become glazed from heavy use (the surface texture feels smoother than when new), light sanding with 1000-grit sandpaper restores the grip. Eventually the coating wears and needs replacement — budget for a spare plate.

Fix 3: Brim

A brim is a flat ring of additional perimeters printed around the base of your model. It does not become part of the print — you remove it afterward — but it significantly increases the surface area adhering to the bed at the base of the model, which counteracts the contraction forces that cause warping.

In your slicer, enable brim and set it to 5-10mm width (3-6 perimeter lines). For tall, thin objects or models with small footprints, go up to 15mm. For ABS and ASA printing, always use a brim.

The cost: about 2 minutes of cleanup after printing to remove the brim. Worth it for any model that has even slight warping.

Fix 4: Enclosure (for ABS and ASA)

If you are trying to print ABS or ASA on an open-frame printer: you have found the source of your problem. These materials require the ambient temperature around the print to be maintained at 40-50°C throughout the print. Even with a 110°C bed, cold room air hitting the print causes the thermal gradient that produces warping.

Solutions in order of effectiveness:

Use an enclosed printer — Creality K1C ($399) or Bambu P1S ($699) are the printers I recommend. The enclosure maintains chamber temperature and the difference is night and day for ABS.
Buy an enclosure tent ($40-80) — Check price on Amazon — These clip-on enclosures trap heat around open-frame printers. They work reasonably well for PETG and mild-warp situations, less well for serious ABS warping.
Switch materials — PETG is almost as functional as ABS for most applications and prints on open-frame machines without enclosure concerns. ASA is UV-stable and printable in an enclosure. If you do not absolutely need ABS, PETG is easier in every way.

Failure 2: Stringing

What it looks like: Thin plastic hairs or threads connecting parts of the print where the nozzle traveled over open air. On a model with multiple pillars, you see a web of fine plastic strings between them. Sometimes called “hairy prints.”

Why it happens: When the nozzle travels from one part of the print to another over open space, molten plastic continues to ooze from the nozzle tip due to pressure inside the hotend. The printer uses retraction — a small backward pull of the filament — to reduce this oozing pressure during travel moves. If retraction is insufficient, the temperature is too high, or travel speed is too slow, the nozzle leaves a trail of plastic across the gap.

Fix 1: Retraction Distance and Speed

Retraction is the most directly tunable setting for stringing.

For direct drive extruders (Bambu machines, Neptune 4 Pro, most modern printers): Start at 0.4-0.8mm retraction distance. Going higher than 1mm on direct drive risks clogging the hotend by pulling molten filament up into the cold zone.

For Bowden extruders (older machines): Retraction distances of 4-7mm are typical due to the longer filament path.

Retraction speed should be 35-45mm/s for most materials. Slower retraction does not fully depressurize the nozzle before travel; faster can cause filament grinding.

Run a retraction test tower — available free on Printables.com — to find your exact optimal retraction distance. Print the same model at 0.2mm increments of retraction distance and identify the sweet spot where stringing disappears without introducing gaps in the print.

Fix 2: Printing Temperature

Hotter plastic is more liquid and oozes more easily. If you are printing PLA at 220°C and seeing significant stringing, try 210°C. For PETG at 250°C, try 240°C.

Run a temperature tower: A temperature tower is a single model printed at decreasing temperatures from bottom to top (e.g., 230°C at the bottom to 190°C at the top, dropping 5°C every 5mm of height). Look for the zone that has:

No stringing between sections
No surface bubbling or rough texture (undertemperature)
Adequate layer adhesion (layers do not separate when you press the print)

Once you find that zone, set your print temperature there. Most PLA prints well at 205-215°C; most PETG prints well at 230-240°C. Bambu’s filament presets nail this for their own filament and come close for most third-party brands.

Fix 3: Travel Speed

A faster travel move (the non-printing movement across open space) gives the nozzle less time to ooze during the trip. Setting travel speed to 150-200mm/s on most machines reduces stringing compared to the default 100mm/s on some older slicers.

In OrcaSlicer: under Printer Settings > Machine Limits > Maximum Travel Speed. In Bambu Studio, this is managed by the quality preset and rarely needs manual adjustment.

Fix 4: Enable “Combing”

Combing (called “avoid crossing perimeters” in some slicers) routes travel moves through the interior of the model rather than crossing open space. Even if some oozing happens during travel, it occurs inside the solid part of the model where it is not visible. This can dramatically reduce visible stringing on complex models without changing any temperature or retraction settings.

Enable combing in OrcaSlicer under Layer & Perimeters > Seam. In Bambu Studio, this is handled automatically by default.

Real User Complaint

From r/3Dprinting: “I’ve been chasing my stringing problem for two weeks and tried everything. Turns out it was wet filament all along. Dried the spool for 6 hours and the stringing went from a spider web to almost nothing.” — u/PrusaMakesGoodStuff

Dry your filament before adjusting settings. It saves hours of troubleshooting.

Failure 3: Layer Delamination

What it looks like: Layers separating from each other. Sometimes visible as horizontal cracks or splits in the print. Sometimes only apparent when you try to snap the part and it breaks cleanly along a layer line rather than through the material.

Why it happens: Layers bond by the heat of the freshly deposited plastic above them. If there is not enough heat, or the layer below has cooled too much before the next layer arrives, the bond is weak. Layer delamination is most common with ABS, nylon, and temperature-sensitive filaments; it is relatively rare with PLA at normal settings.

Fix 1: Raise Nozzle Temperature

If layers are delaminating, your first adjustment is to raise nozzle temperature by 5°C increments and test.

PLA: If seeing delamination at 205°C, try 210°C then 215°C.
ABS: If seeing delamination at 240°C, try 245°C then 250°C.
PETG: If seeing delamination at 235°C, try 240°C.

Note: going too high introduces other problems (stringing, surface blobbing). Use the temperature tower to find the range before committing to an extreme value.

Fix 2: Slow Down or Use an Enclosure

Fast printing gives each layer less time at elevated temperature before the next layer arrives. If you are printing at 400mm/s and seeing delamination, try slowing to 200mm/s on the same model. If delamination disappears at lower speeds, your temperature is marginal — either raise temp slightly or accept the lower speed.

For ABS and ASA, delamination almost always traces back to the absence of an enclosure. Cold ambient air rapidly cools the print between layers.

Fix 3: Reduce Part Cooling Fan Speed

Your part cooling fan pulls heat away from the freshly deposited layer. This is useful for overhangs and bridges (cooling plastic in mid-air before it droops), but if the fan is set too high for your temperature, it can cool layers faster than the next layer can bond.

PLA: 70-100% fan speed is normal.
PETG: Reduce to 30-50%. PETG is more sensitive to rapid cooling and benefits from slower cooling for better layer adhesion.
ABS: 0-20% fan speed. ABS needs to cool slowly for layer bonding. This is another reason it requires an enclosure — the fan + cold ambient air combination destroys layer adhesion.

Failure 4: Under-Extrusion

What it looks like: Gaps in the surface of your print. Infill lines that do not touch each other. Thin walls that look incomplete. A grid pattern in solid surfaces that should be fully filled. The print is there but it looks porous or holey.

Why it happens: The printer is not delivering enough plastic. This can be because: the flow rate (extrusion multiplier) is set too low, a partial clog is restricting flow, the filament has a dimensional inconsistency, the temperature is too low for the material to flow properly, or the print speed is higher than the hotend can melt filament to keep up with.

Fix 1: Check for a Partial Clog

A partial clog is the most common cause of under-extrusion that does not respond to obvious settings fixes. Carbonized filament, dust, or a leftover fragment from a previous filament type can partially block the nozzle.

Cold pull: Heat the nozzle to printing temperature, push a piece of nylon filament through by hand until it extrudes cleanly, then cool the nozzle to 90°C (for PLA) while maintaining slight forward pressure. At 90°C, pull the filament out firmly in a single smooth motion. It should pull out with the shape of the inside of the nozzle, including any debris. If you see a brown or colored plug on the cold pull, your nozzle was partially clogged. Repeat 2-3 times until the pulled piece is clean.

Fix 2: Raise Extrusion Multiplier (Flow Rate)

The extrusion multiplier (called “flow rate” in some slicers) is a percentage that scales the amount of filament the printer pushes. 100% is nominal; if your printer is calibrated correctly, 100% should deliver exactly the right amount. In practice, filament diameter variation, extruder gear wear, and measurement error mean many printers run best at 95-105%.

How to find your correct flow rate: Print a single-wall cube (20 x 20 x 20mm, 1 perimeter, 0% infill, no top or bottom layers) and measure the wall thickness with calipers. Your target wall thickness equals your nozzle diameter (0.4mm for stock). If the wall measures 0.35mm, your flow is low — raise the multiplier by 5-10%. If it measures 0.45mm, lower it.

Adjust in 5% increments and retest until wall thickness matches nozzle diameter.

Fix 3: Print Slower or Raise Temperature

Under-extrusion at high speeds often indicates the hotend cannot melt filament fast enough to keep up with demand. The solution is either to slow down or to raise temperature (so filament melts faster).

If you are printing PLA at 400mm/s and seeing under-extrusion: slow to 250mm/s and see if it resolves. If it does, your max reliable speed for that filament and temperature combination is around 250mm/s. A higher temperature (5°C increment) will increase melt rate and may allow higher speeds.

Failure 5: Over-Extrusion

What it looks like: Blobby, rough surface with excess material. Nozzle dragging through the surface and picking up blobs. Rounded edges instead of sharp corners. Perimeters that bulge and touch each other.

Why it happens: The printer is depositing too much plastic. Usually caused by an extrusion multiplier set too high, a miscalibrated extruder (E-steps), or printing temperature too high.

Fix 1: Lower Extrusion Multiplier

Same process as under-extrusion tuning, just in the other direction. Print the single-wall cube, measure the wall, and lower the flow rate in 5% increments until the wall thickness matches your nozzle diameter.

Fix 2: Calibrate E-Steps

E-steps (extruder steps per millimeter) is the value that tells the printer how many motor steps are required to push 1mm of filament. If this is wrong, every print will be over- or under-extruded regardless of flow rate.

To calibrate: Mark your filament 120mm and 100mm from the extruder entrance with a marker. Command the printer to extrude 100mm of filament. Measure how much actually moved past the 100mm mark. If it moved 105mm instead of 100mm, your E-steps are 5% too high. Calculate the corrected value: (current E-steps) x 100 / (actual extrusion) and update in firmware or EEPROM.

Bambu printers do this automatically. For Klipper machines (Neptune 4 Pro, Ender 3 V3), the rotation_distance parameter in printer.cfg is the Klipper equivalent of E-steps.

Fix 3: Lower Temperature

At higher temperatures, filament flows more freely and may extrude slightly more than commanded. If you have been running PLA at 225°C, try 215°C. This is often the first fix to try if you see mild blobbing at the start of lines.

Failure 6: Elephant Foot

What it looks like: The bottom of your print is slightly wider than the rest, creating a flared base that looks like the bottom of an elephant’s leg. The first layer or two spreads out further than the model’s actual diameter.

Why it happens: Two causes. First: the nozzle is too close to the bed, squishing the first layer flat and causing it to spread outward. Second: the bed temperature is high enough to keep the first layer soft while the nozzle continues to push material downward, causing it to mushroom outward.

Fix 1: Adjust Z-Offset (First Layer Height)

Your Z-offset is how close the nozzle is to the bed at the start of the first layer. Too close: elephant foot. Too far: first layer does not stick (gaps between lines, poor adhesion).

The target first layer should look like slightly-squished lines that are fused together, with the top surface of the lines being smooth. If the lines look very flat and wide — completely squished — raise your Z-offset (move the nozzle further from the bed). In most slicer interfaces and printer menus, reducing the Z-offset number brings the nozzle closer; increasing it moves the nozzle away.

Adjust in 0.025-0.05mm increments and re-print the first layer until the lines look right.

Fix 2: Lower Bed Temperature for First Few Layers

If your Z-offset is correct but you still see elephant foot: try lowering the bed temperature by 5°C for the first two layers (most slicers allow per-layer temperature control), then bringing it back to the target temperature from layer 3 onward. This reduces the softness of the plastic at the base and limits outward spreading.

In Bambu Studio: under Filament > Temperatures, set a separate “first layer” bed temperature.

Fix 3: Enable “Elephant Foot Compensation”

OrcaSlicer and Bambu Studio both have an elephant foot compensation setting that automatically shrinks the first layer perimeters by a defined amount to compensate for the expected spreading. In OrcaSlicer: under Layer and Perimeters > Elephant Foot Compensation. A value of 0.1-0.2mm is usually sufficient for mild elephant foot.

Diagnostic Flowchart

Use this to identify what you are looking at.

Is the print not sticking to the bed?
├── Yes → Check Z-offset, clean plate with IPA, increase bed temp, add brim
└── No ↓

Are there holes, gaps, or incomplete surfaces?
├── Yes → Under-extrusion
│   ├── Do you hear popping/crackling? → Dry the filament
│   ├── Is flow consistent at all speeds? → Check for partial clog (cold pull)
│   └── Is flow consistent after cold pull? → Calibrate E-steps, raise temp
└── No ↓

Is there extra plastic, blobbing, or rough surfaces?
├── Yes → Over-extrusion
│   ├── Lower extrusion multiplier 5% and retest
│   └── Lower temperature 5°C and retest
└── No ↓

Is the bottom flared wider than the rest of the model?
├── Yes → Elephant foot
│   ├── Raise Z-offset by 0.025-0.05mm
│   └── Enable elephant foot compensation in slicer
└── No ↓

Are there thin plastic hairs between parts?
├── Yes → Stringing
│   ├── Is filament crackling during printing? → Dry the filament
│   ├── After drying, still stringing? → Increase retraction 0.2mm and retest
│   └── After retraction fix, still stringing? → Lower temperature 5°C
└── No ↓

Are there horizontal cracks or weak layer bonding?
├── Yes → Layer delamination
│   ├── Is material ABS or ASA on open frame? → Need enclosure
│   ├── PLA or PETG delaminating? → Raise temp 5°C, lower fan speed
│   └── Still delaminating? → Slow print speed to allow better bonding
└── No ↓

Is the print visually good but dimensionally inaccurate?
└── Yes → Calibrate E-steps / rotation_distance, run flow rate calibration

The Companion Products That Actually Fix Problems

Beyond the fixes above, these products have solved real recurring issues in my setup:

SUNLU S2 Filament Dryer ($40) — Check price on Amazon — Eliminates moisture-related stringing and surface defects. The single most impactful $40 you can spend.
Digital Calipers ($15-25) — Check price on Amazon — Required for accurate flow rate calibration and E-step calibration. Measure wall thickness, not just eyeball it.
Nylon Filament ($20/kg) — Check price on Amazon — For cold pulls. You do not need to print with it; just keep a short piece for nozzle cleaning.
Hardened Steel Nozzles ($15 for a 5-pack) — Check price on Amazon — If you print abrasives, replace before you need to. A worn nozzle mimics under-extrusion.
PEI Build Plate Replacement ($12-20) — Check price on Amazon — A glazed, worn plate that has lost its texture causes warping and adhesion failures that no settings change will fix.
Desiccant Packs ($8 for a 20-pack) — Check price on Amazon — For storing filament in sealed bags or containers between print sessions.
Polymaker PolyTerra PLA ($20/kg) — Check price on Amazon — When I am debugging print failures, I switch to a known-good, recently-dried reference filament so I can isolate the variable. PolyTerra is my reference PLA.

The Most Common Mistake (And How to Avoid It)

Changing multiple settings at once.

I did this constantly as a beginner and it made troubleshooting impossible. If you change temperature, retraction, and speed all at the same time and the print gets better, you have no idea which change helped and which made things worse. If you change them all and the print gets worse, you have no idea where to start.

Troubleshoot one variable at a time. Change one setting. Print a test. Evaluate. Change the next setting. It feels slower, but it is genuinely faster than the “change everything and hope” method that keeps you in a loop for weeks.

The Teaching Tech calibration guide (search “Teaching Tech calibration” on YouTube or find his browser-based tool) walks through this methodically — temperature tower, retraction test, flow calibration in sequence. Follow that process once with a new filament on a new machine and you will have reliable settings for every print going forward.

The community on r/FixMyPrint is also excellent for this — post a photo of your failed print and someone will tell you exactly what to fix. The diagnosis from a photo is often faster than working through every variable yourself.

Last updated March 2026.