Troubleshooting
3D Print Troubleshooting
Symptom-first fixes for every common 3D printing failure. Material-specific advice, actual slicer settings, and none of the "check your settings" runaround.
Stringing / Oozing
Thin wisps of plastic between travel moves. The single most common complaint on every 3D printing forum.
Stringing happens when molten filament leaks from the nozzle during non-printing travel moves. The nozzle lifts, moves to a new position, and leaves a thin hair of plastic behind. Some amount is normal with certain materials, but excessive stringing means something is off.
Before you touch retraction settings: check if the filament is wet. Moisture is the #1 cause of stringing that doesn't respond to retraction tuning. You can spend hours dialing in retraction and it won't help if the real problem is steam pushing plastic out of the nozzle.
Why It Happens
Temperature Too High
Hotter plastic is thinner and oozes more easily. If you're printing PLA at 220°C and stringing, drop to 200-205°C. Run a temp tower to find the sweet spot for your specific brand.
Retraction Too Low
Retraction pulls filament back to relieve pressure in the melt zone. Direct drive: 0.5-2mm. Bowden: 4-7mm. If retraction is set to 0 or 1mm on a Bowden setup, that's your problem.
Wet Filament
Steam from moisture creates internal pressure that pushes plastic out during travels. No amount of retraction fixes this. Dry the filament first, then tune retraction.
Travel Speed Too Low
Slower travel = more time for ooze. Increase travel speed to 150-200mm/s. The nozzle moves faster between points, giving less time for plastic to drool.
Material-Specific Notes
PLA: Easiest to fix. Drop temp to 195-205°C, retraction 1-2mm (direct drive) or 5-6mm (Bowden), retraction speed 40-50mm/s. If it still strings, the filament is wet.
PETG: Strings more than PLA by nature. PETG is stickier and has a wider melt range. Use retraction speed of 30-40mm/s (slower than PLA - fast retraction causes jams in PETG). Enable "Wipe while Retracting" in PrusaSlicer or "Wipe" in Cura. Accept some micro-stringing as normal.
TPU: Strings by design because you cannot use retraction with most Bowden setups (it compresses instead of retracting). On direct drive, try 0.5-1mm retraction at 20-25mm/s. Print hotter than you think (225-235°C) but slower (25-35mm/s). TPU stringing is best cleaned up post-print with a heat gun.
ABS/ASA: Similar to PLA retraction settings. Drop temp to 235-240°C if stringing. Make sure the enclosure isn't overheating the hotend above its target temp.
Fixes to Try (In Order)
1. Dry the filament. Especially if it's been open for more than a week. 60°C for 4-6h for PLA, 65°C for 4-6h for PETG. See the storage guide for drying temps by material.
2. Drop print temperature by 5°C. Print a stringing test (two columns 50mm apart) at your current temp, then 5°C lower. Repeat until quality drops or stringing stops.
3. Increase retraction distance by 0.5mm. Test incrementally. Too much retraction causes clogs, so don't just crank it to 10mm.
4. Increase retraction speed to 40-50mm/s. Faster retraction pulls the filament back more decisively. Exception: PETG jams above 40mm/s on some hotends.
5. Enable coasting. In Cura: "Coasting Volume" 0.064mm3. In PrusaSlicer/OrcaSlicer: not natively supported, but "Wipe while Retracting" has a similar effect. Coasting stops extrusion slightly before the end of a perimeter to depressurize the nozzle.
6. Increase travel speed. Set to 150-200mm/s. Less hang time = less ooze. Make sure "Combing" (Cura) or "Avoid crossing perimeters" (PrusaSlicer) is enabled so travels stay inside the model when possible.
Warping / Lifting
Corners and edges lift off the bed mid-print. The part curls upward, sometimes enough to hit the nozzle and knock itself loose.
Warping is caused by thermal contraction. Plastic shrinks as it cools, and if the bottom of the print is bonded to the bed while the upper layers are contracting, the internal stress literally pulls the corners up. The larger the footprint, the worse it gets.
Materials with high shrinkage rates (ABS, ASA, Nylon, PC) warp far more than low-shrinkage materials (PLA, PETG). If you're printing PLA and getting warping, the fix is almost always bed adhesion or first layer settings. If you're printing ABS without an enclosure, warping is basically guaranteed.
Material Warping Severity
| Material | Warp Risk | Enclosure Needed? | Bed Temp |
|---|---|---|---|
| PLA | Very low | No | 55-65°C |
| PETG | Low-moderate | No (helps for large parts) | 75-85°C |
| ABS | High | Yes - required | 100-110°C |
| ASA | High | Yes - required | 100-110°C |
| Nylon (PA) | Very high | Yes - required | 70-90°C (with glue) |
| TPU | Very low | No | 50-60°C |
| PC | Very high | Yes - required | 110-120°C |
Fixes
Add a brim. A brim adds extra surface area around the base of the print, dramatically increasing bed grip. 5-8mm brim width is typical. In OrcaSlicer/PrusaSlicer: "Brim width" under Skirt/Brim. In Cura: "Build Plate Adhesion Type" → Brim.
Use an enclosure for ABS/ASA/Nylon. These materials need stable ambient temperature to cool evenly. A proper enclosure keeps the air above 40°C and blocks drafts. Even a cardboard box or IKEA LACK table enclosure makes a massive difference. Without it, you're fighting physics.
Increase bed temperature by 5°C. A hotter bed keeps the base of the print softer and more compliant, reducing the stress from upper layers shrinking. But don't go too high or you get elephant foot.
Kill all drafts. Open windows, AC vents, and even walking past the printer can cause enough air movement to trigger warping on ABS. Close the room, turn off fans pointed at the printer, and if you don't have an enclosure, at least drape a towel over the top.
Apply adhesive. Glue stick (PVA - the purple Elmer's kind) works brilliantly for Nylon, PC, and PETG. Thin layer, let it dry, print on top. Hairspray (Aqua Net) works well for ABS/ASA. For PLA on textured PEI, you usually don't need anything.
Tune first layer settings. A properly squished first layer with slower speed (20-25mm/s) and slightly higher flow (+5%) grips the bed much better. See the first layer guide for the full rundown.
Avoid sharp corners in your design. If you have design control, add fillets to corners that touch the bed. Sharp 90-degree corners concentrate stress and are the first to lift. A 2-3mm fillet distributes the force across a curve.
Layer Separation / Delamination
Layers peel apart or crack along the Z-axis. The print looks fine from above but splits when you apply force - or even spontaneously mid-print.
Layer adhesion depends on the new layer being hot enough to partially re-melt and bond with the layer below it. If the nozzle temperature is too low, the layer height is too thick, or the previous layer has cooled too much, the bond between layers is weak. The print becomes a stack of separate discs instead of a solid object.
This is one of the failures where "my slicer profile was working fine last week" often traces back to a new spool of filament that needs different temps, or a change in ambient temperature (printing in a cold garage in winter vs. summer).
Common Causes
Nozzle Temp Too Low
This is the cause 80% of the time. Each layer needs to be hot enough to bond to the one below. Increase temp by 5-10°C and test. Different brands of the same material can need very different temps.
Layer Height Too Thick
Thicker layers have less surface contact and cool faster. If you're printing at 0.32mm layer height and getting delamination, drop to 0.2mm. General rule: layer height should be 25-75% of nozzle diameter.
Wet Filament
Steam bubbles create voids between layers, weakening the bond. If you hear crackling while printing, the filament is wet. Dry it before troubleshooting anything else.
Too Much Cooling
Part cooling fan at 100% on ABS/ASA is a guaranteed recipe for delamination. ABS: fan off or 0-15%. ASA: 0-20%. PETG: 30-50%. PLA can handle 100% after the first few layers.
Material-Specific Fixes
ABS/ASA: Need an enclosure. Ambient temp below 35°C causes layer separation on tall prints because upper layers cool too fast. Nozzle at 240-250°C, fan off, bed at 100-110°C. If you still get splits, the enclosure is leaking heat.
PETG: Needs higher temps than most people set. 235-245°C nozzle, not the 220°C that some slicer defaults suggest. PETG at 220°C prints fine visually but snaps apart at layer lines under load. Push the temp up.
Nylon: Extremely prone to delamination without an enclosure. Print at 250-260°C, bed 70-90°C, fan off, enclosure mandatory. Even then, thick Nylon parts benefit from annealing after printing.
PLA: Rarely delaminates unless severely under-temperature or the filament is ancient and brittle. If PLA layers split, check the filament age and moisture level first. Increase temp to 210-215°C.
Quick Fixes
Increase nozzle temp by 5-10°C. The simplest and most effective fix. Test with a layer adhesion test print (a thin-walled vase or tensile bar).
Decrease layer height. Drop from 0.28 to 0.2mm, or from 0.2 to 0.16mm. More contact area between layers = stronger bond.
Increase line width. Wider extrusion lines overlap more with the layer below. Try 110-120% of nozzle diameter (e.g. 0.44-0.48mm for a 0.4mm nozzle). In PrusaSlicer: "Extrusion width". In Cura: "Line Width".
Reduce part cooling fan speed. Especially for the first 5-10 layers and for anything printed in ABS/ASA/Nylon. In PrusaSlicer: "Min fan speed" and "Bridges fan speed" are separate - reduce the former.
Print slower. Slower extrusion means the hotend has more time to melt the plastic fully. Drop print speed by 20% and see if adhesion improves.
Elephant Foot
The first few layers bulge outward, making the base of the print wider than the rest. Named for the obvious reason.
Elephant foot happens when the bottom layers are too soft (bed too hot), too squished (nozzle too close), or both. The weight of the layers above presses down on the still-soft base, causing it to spread. It's cosmetic on decorative prints but a real problem for parts that need to fit together or slot into assemblies.
Bed Temp Too High
The most common cause. Lower bed temp by 5°C. If you're running PLA at 65°C, try 55-60°C. For PETG at 85°C, try 75-80°C.
Nozzle Too Close
Over-squished first layer spreads wider than it should. Increase Z-offset slightly (less negative). Even +0.02-0.04mm can fix elephant foot without hurting adhesion.
First Layer Flow Too High
If first layer flow is set above 100% (some profiles default to 105-110%), the extra plastic has nowhere to go but outward. Drop it back to 95-100%.
Slicer Compensation
PrusaSlicer and OrcaSlicer have "Elephant foot compensation" - it insets the first layer by a set amount (try 0.1-0.2mm). Cura calls it "Initial Layer Horizontal Expansion" (set to -0.1 to -0.2mm).
Fix Order
1. Lower bed temp by 5°C. This alone fixes most elephant foot. Don't go so low that you lose adhesion though - test with a first layer calibration print.
2. Raise Z-offset by 0.02mm. Small adjustment. You're looking for the point where the first layer is still squished enough to stick but not bulging outward.
3. Enable elephant foot compensation in the slicer. Start at 0.1mm and increase if needed. This is a post-processing compensation that slightly shrinks the first layer outline to counteract the spreading.
4. Reduce initial layer flow to 95%. Less plastic = less spreading. Only if the above three don't fully resolve it.
Under-Extrusion
Gaps in the walls, missing layers, thin wispy infill, or the print just looks starved for plastic.
Under-extrusion means less filament is being deposited than the slicer expects. The symptoms range from subtle (slightly rough top surfaces, weak parts) to obvious (gaps between perimeters, visible holes in walls, infill that looks like spider webs).
The tricky part is that under-extrusion has many possible causes, and they compound. A partial clog plus slightly low temp plus a worn drive gear can individually be fine but together result in chronic under-extrusion.
Common Causes
Partial Clog
The #1 cause. Carbon buildup or degraded filament narrows the nozzle bore. Do a cold pull: heat to 200°C, push filament through, cool to 90°C, then pull sharply. The tip of the filament should come out with a clean cone shape. Repeat until clean.
Temp Too Low
Plastic that isn't fully melted creates back-pressure the extruder can't overcome at the expected flow rate. Increase temp by 5-10°C. This is especially common with PETG and Nylon where people use PLA temperatures.
Worn Drive Gear
The hobbed gear that grips the filament wears smooth over time (especially with abrasive filaments like carbon fiber or glow-in-the-dark). Inspect it - if the teeth are rounded or clogged with shavings, replace it. A new gear is a few dollars and takes 10 minutes.
Wet Filament
Steam voids take up space where plastic should be. The extrusion looks foamy and inconsistent. Dry the filament and compare before and after.
Fixes
Cold pull. The universal first step for any extrusion issue. Use Nylon or cleaning filament for best results. If you don't have cleaning filament, PLA works - heat to printing temp, push through, cool to 85-95°C, pull. Repeat 3-5 times.
Increase nozzle temp by 5-10°C. More heat = lower viscosity = easier flow. If the under-extrusion is worst at high print speeds, the hotend can't melt fast enough. Either increase temp or slow down.
Check extruder tension. On direct drive (like Bambu, Prusa MK4): the tension should hold the filament firmly against the drive gear without crushing it. Too loose = slipping. Too tight = grinding a flat spot and then slipping.
Calibrate e-steps/rotation distance. Mark 120mm of filament above the extruder entry, extrude 100mm via the LCD/Klipper console, measure what's left. If it extruded only 95mm, your e-steps are 5% low. Adjust in firmware. In Klipper:
rotation_distance in printer.cfg.Check the PTFE tube (Bowden systems). A gap between the PTFE tube and the nozzle is a clog magnet. If your Bowden tube has a burnt, swollen, or frayed end, trim it flat with a PTFE tube cutter and reseat it flush against the nozzle.
Check spool binding. If the spool can't rotate freely on its holder, the extruder has to fight the drag. This causes intermittent under-extrusion that's worse on the inner wraps of the spool. Make sure the spool rotates smoothly and the filament path doesn't have sharp bends.
Over-Extrusion / Blobs
Surfaces are rough and blobby, dimensions are oversized, and perimeters bulge outward at corners and seams.
Over-extrusion is the opposite problem: more plastic is being pushed out than the slicer expects. Walls are thicker than designed, holes are smaller, surfaces have a rough, pimply texture, and the nozzle may drag through excess material on top layers. Zits and blobs at the layer seam are the most visible symptom.
Common Causes
Flow Rate Too High
If flow multiplier (PrusaSlicer) or Flow Rate (Cura) is above 100%, try reducing to 95-97%. Print a single-wall calibration cube and measure wall thickness with calipers - it should match your line width setting.
Temp Too High
Overheated plastic flows too easily. It oozes at pauses and bulges at perimeters. Drop temp by 5°C at a time until surface quality improves without losing layer adhesion.
E-Steps Over-Calibrated
If you calibrated e-steps but measured wrong (or used the wrong formula), the extruder pushes out 105% or more of what's expected. Re-run the 100mm extrusion test to verify.
Incorrect Filament Diameter
If the slicer thinks filament is 1.75mm but it's actually 1.80mm, it under-calculates flow. Measure your filament diameter at 3-4 points with calipers and enter the average in the slicer's filament settings.
Fixes
Print a flow calibration cube. Single-wall (one perimeter, no infill, no top layers) cube. Measure wall thickness with calipers. If you set line width to 0.4mm and the wall measures 0.44mm, reduce flow to (0.4 / 0.44) * 100 = 91%. Some slicers call this "Extrusion Multiplier".
Reduce print temperature by 5°C. Over-extrusion and temperature are linked - hotter plastic flows more freely, amplifying any existing over-extrusion from flow calibration.
Enable coasting. Stops extrusion slightly before the end of each segment to bleed off nozzle pressure. In Cura: "Enable Coasting", set volume to 0.064mm3. Helps with corner blobs and seam zits.
Tune pressure advance / linear advance. This is the real fix for blobs at corners and seams. Klipper:
pressure_advance in printer.cfg (typical range 0.02-0.08 for direct drive). Marlin: M900 K (Linear Advance). Cura has a "Linear Advance" plugin. Run a PA calibration pattern to find your value.Try scarf seams. If seam blobs are your main issue, scarf joint seams in OrcaSlicer/PrusaSlicer 2.8+ gradually taper the extrusion at the seam start/end, virtually eliminating the blob. Full seam guide →
Z-Banding / Visible Layer Lines
Repeating horizontal lines or ridges on the side of the print at regular intervals. The surface looks like it has bands or ripples.
Some layer visibility is inherent to FDM printing - you're stacking 0.2mm layers, and at some angle you'll always see them. Z-banding is different: it's a repeating pattern where certain layers are wider or offset than others, creating visible ridges that you can feel with your fingernail.
The repeating pattern is the key diagnostic clue. If the banding repeats every 2mm on a printer with a 2mm-pitch lead screw, the Z-axis mechanics are the prime suspect.
Common Causes
Z-Axis Lead Screw Issues
A bent lead screw, dry lead screw, or binding anti-backlash nut causes inconsistent Z movement. The nozzle doesn't rise by exactly the right amount each layer. Clean the lead screw and apply a thin coat of PTFE-based lubricant (not WD-40, not grease). If it's visibly bent, replace it.
Loose Coupler
The coupling between the Z stepper motor shaft and the lead screw can slip if the set screws loosen. The screw turns but the lead screw doesn't move the full distance. Tighten both set screws (usually two per coupler) and make sure one sits on the flat of the motor shaft.
Vibration
A printer on a wobbly table or a lightweight IKEA shelf will vibrate during fast moves, causing ringing artifacts that can look like banding. Place the printer on a heavy, solid surface. Anti-vibration feet (rubber or silicone) help dampen motor vibration transferred through the frame.
Inconsistent Extrusion
If the extruder output fluctuates (from a partial clog, filament grinding, or a failing hotend heater causing temperature swings), some layers get more plastic than others. Check PID tuning - run
M303 in Marlin or PID_CALIBRATE in Klipper to auto-tune the hotend heater.Fixes
Lubricate the Z-axis lead screw. Apply a small amount of PTFE dry lube or white lithium grease. Run the Z axis up and down a few times to distribute it. Wipe off excess - you want a thin film, not a puddle.
Check and tighten Z coupler set screws. With the printer off, try to twist the lead screw while holding the motor shaft. If there's any play or rotation without the motor turning, the coupler is loose.
Place the printer on a solid, heavy surface. A concrete slab, thick wooden workbench, or a heavy paving stone under the printer all help. The more mass and rigidity, the less vibration transfers into the print.
Add anti-vibration feet. Sorbothane pads or silicone feet between the printer and the surface absorb motor vibrations. Cheap and effective.
PID tune the hotend. Temperature fluctuations cause extrusion inconsistency. Marlin:
M303 E0 S210 C8 (PID autotune at 210°C, 8 cycles), then M500 to save. Klipper: PID_CALIBRATE HEATER=extruder TARGET=210, then SAVE_CONFIG.Check for Z-axis binding. With steppers disabled, move the gantry up and down by hand. It should move smoothly with no tight spots. If you feel resistance at certain heights, the lead screw is bent or the linear bearings/rods are misaligned.
First Layer Issues
The first layer is the foundation. Most "mid-print" failures actually start here. We have a dedicated deep-dive guide for this.
First layer problems are so common and have so many interacting variables that they deserve their own guide. If your first layer isn't sticking, is too squished, has gaps between lines, or looks inconsistent across the bed, head to the First Layer Calibration Guide for the full breakdown.
Quick Checklist
Bed level: Run ABL mesh or manually re-level. A 0.1mm tilt across the bed is enough to ruin one corner while the opposite is fine.
Z-offset: Calibrate at printing temperature (both nozzle and bed). The first layer should be slightly squished, not round in cross-section. Adjust in 0.02mm increments.
First layer speed: Set to 20-25mm/s. Slow first layer gives the plastic time to wet out and bond with the surface.
Bed temp: PLA 55-65°C, PETG 75-85°C, ABS/ASA 100-110°C. Material-specific temps matter.
Clean bed: IPA wipe before every print. Fingerprints leave oil that prevents adhesion. For stubborn residue, use dish soap and hot water, dry completely.
First layer height: Set to 0.2-0.28mm (even if the rest of the print is at 0.12mm). A thicker first layer is more forgiving of slight bed imperfections.
Clicking / Grinding Extruder
A rhythmic clicking, clunking, or grinding sound from the extruder. The drive gear is skipping because it can't push filament forward.
The extruder motor has a finite amount of torque. When something downstream creates more resistance than the motor can overcome, the drive gear slips against the filament and you hear that distinctive click. Each click is a missed step where no filament was pushed. The result is under-extrusion, with a telltale chewed-up section of filament where the gear was grinding.
Common Causes
Partial or Full Clog
The most common cause. Buildup in the nozzle or heat break restricts flow. The extruder pushes harder until the gear slips. Do a cold pull to clear it. If cold pulls don't help, the clog may be in the heat break - a full disassembly and cleaning may be needed.
Printing Too Cold
If the filament isn't fully melted, it creates a solid plug the extruder can't push past. Increase temp by 5-10°C. This is common when switching from PLA to PETG or Nylon without updating the temperature profile.
Printing Too Fast
High flow rate exceeds the hotend's melt capacity. The plastic can't melt fast enough to flow at the requested rate. Reduce print speed by 20-30%, or increase temp by 5-10°C to compensate. High-flow hotends (Revo, Rapido, Bambu) handle faster speeds than stock V6-style hotends.
Idler Tension Wrong
Too tight: the gear bites too deep into the filament, creating a divot that reduces grip on subsequent passes. Too loose: the gear can't grip at all. Adjust until the filament has visible but shallow teeth marks - not a deep gouge.
What to Do When You Hear Clicking
1. Stop the print. Continuing with a clicking extruder makes everything worse. The gear grinds a flat spot into the filament, which then can't be gripped at all, and you get a full jam.
2. Remove and inspect the filament. Pull it out and look at the section that was in the extruder. If there are deep gouges or a flat spot, the tension is too tight. If it looks clean (no gear marks), the tension is too loose.
3. Do a cold pull. Even if you're not sure it's a clog. Cold pulls are fast and eliminate the most common cause. Use Nylon if available, otherwise PLA at 85-95°C pull temp.
4. Increase temp by 10°C and retry. If the cold pull was clean, the issue may be insufficient melt rate. More heat = lower viscosity = less resistance.
5. Reduce print speed by 20%. If increasing temp doesn't help (or you're already at the material's max temp), slow down. The volumetric flow rate may exceed what your hotend can deliver.
6. Check the PTFE tube. On Bowden systems and some direct drives (like the Ender 3's all-metal heat break conversion), a gap or damaged PTFE tube in the hot zone causes filament to blob and jam. Inspect and replace if the tip is deformed.
Wet Filament Symptoms
Moisture in filament causes a constellation of symptoms that mimic other problems. If you're chasing multiple issues at once and nothing seems to fix them, the filament is probably wet.
Water molecules lodge between polymer chains in the filament. When the filament hits the hotend at 200°C+, that water flash-boils into steam, creating micro-bubbles in the melt. The effects cascade: stringing from internal pressure, rough surfaces from popping bubbles, weak layer bonds from voids, and inconsistent extrusion from fluctuating melt viscosity.
The insidious part is that you can't see moisture in filament. A spool can look and feel perfectly normal and still be saturated enough to ruin prints.
Symptoms
Popping / Crackling
The most obvious sign. Listen while printing - if you hear popping, hissing, or crackling from the nozzle, that's steam escaping. A dry spool is silent during extrusion.
Rough / Bubbly Surface
The surface has a matte, rough, or pockmarked texture instead of the smooth or slightly glossy finish you'd expect. On translucent filaments, you'll see a foamy, opaque appearance.
Excessive Stringing
Steam creates internal pressure that pushes plastic out during travel moves. Retraction can't counteract pressure from boiling water inside the melt zone. If retraction tuning isn't helping, moisture is the likely culprit.
Weak Layer Adhesion
Steam voids between layers weaken the bond. Parts snap along layer lines much more easily than they should. This is especially dangerous for functional parts where you're relying on layer strength.
How to Test
The listening test: Extrude 100mm of filament slowly (2mm/s) into mid-air and listen. Wet filament pops and hisses. Dry filament extrudes silently with a smooth, consistent bead.
The snap test (PLA only): Bend a section of filament sharply. Dry PLA snaps cleanly with a crisp break. Wet PLA bends and deforms before breaking, or just bends without breaking at all. This doesn't work for PETG or Nylon which are naturally flexible.
The visual test: Extrude a thin line onto the bed. Dry filament produces a smooth, consistent line. Wet filament produces a line with tiny bubbles, inconsistent width, or a rough texture.
Drying Recommendations by Material
| Material | Temp | Duration | Sensitivity |
|---|---|---|---|
| PLA | 45-55°C | 4-6 hours | Moderate |
| PETG | 60-65°C | 4-6 hours | Moderate-High |
| ABS/ASA | 65-75°C | 4-6 hours | Low-Moderate |
| TPU | 50-55°C | 6-8 hours | High |
| Nylon (PA) | 70-80°C | 8-12 hours | Very High |
| PC | 70-80°C | 8-12 hours | Moderate |
PLA deforms above 55°C. Never dry PLA in a food dehydrator or oven set higher than 55°C. The glass transition temperature of PLA is around 55-60°C - exceeding it will warp the spool and fuse layers of filament together. Use a purpose-built filament dryer with accurate temperature control.
Prevention is easier than fixing. Store filament in sealed containers with desiccant. Nylon and TPU should be stored in vacuum bags when not in use. Print directly from a dry box if possible. See the Filament Storage & Drying Guide for the full setup.
Frequently Asked Questions
Why is my print stringing even after adjusting retraction? If retraction tuning isn't helping, the filament is almost certainly wet. Moisture creates steam pressure that pushes plastic out during travel moves regardless of retraction settings. Dry the filament first (see drying temps by material), then re-tune retraction. Also check that your printing temperature isn't higher than necessary - drop by 5°C and test.
How do I fix warping on ABS and ASA? You need an enclosure. ABS and ASA shrink significantly as they cool, and uneven cooling causes warping. Bed temp at 100-110°C, enclosure ambient above 40°C, no drafts, brim of at least 5mm, and a thin layer of glue stick for insurance. Without an enclosure, you'll always have warping on anything larger than a benchy.
What causes clicking sounds from the extruder? The extruder gear is skipping because it can't push filament through. Most common cause: partial clog (do a cold pull). Other causes: printing too cold (increase temp by 5-10°C), printing too fast for the hotend's melt capacity (slow down by 20%), or idler tension too tight (the gear is grinding a groove into the filament instead of pushing it).
How can I tell if my filament is wet? Listen for popping or crackling during printing. Extrude 100mm slowly into the air and listen - wet filament pops, dry filament is silent. Other signs: rough/bubbly surface finish, excessive stringing that doesn't respond to retraction tuning, weak layer adhesion. The PLA snap test works too: dry PLA snaps cleanly, wet PLA bends.
Why do I have visible layer lines (Z-banding) on my prints? Repeating banding is usually mechanical: a dry or bent Z lead screw, loose motor coupler, or vibration from an unsteady surface. Lubricate the Z rod with PTFE-based lube, tighten coupler set screws, and place the printer on a heavy solid surface. If the banding is irregular, PID tune your hotend to stabilize temperature.
What's the difference between under-extrusion and a clogged nozzle? A clog is one cause of under-extrusion, but not the only one. Under-extrusion means less plastic than expected. Other causes: temperature too low, worn drive gear, incorrect e-steps, or spool drag. Do a cold pull first to rule out clogs, then check the other causes if the issue persists.