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3D Print Troubleshooting, Calibration & Parts

Symptom diagnoser

What went wrong with your print?

Pick the symptom you can see on the plate. Every fix here is written against a specific failure mode, with the settings that actually change it.

Blobs, zits and a visible seam line A small defect where each layer starts and stops, stacked into a visible line. Cracking and layer delamination Layers separate under load or on their own. Weak bonding from cold plastic or a cold chamber. Drooping overhangs and failed bridges Plastic sags before it sets. Cooling and slower perimeters do most of the work. Elephant foot on the bottom layer The first layers bulge outwards. Too much squish plus a bed hotter than it needs to be. First layer not sticking to the build plate Nine times out of ten the plate is contaminated with skin oil, not badly levelled. Wash it before you touch the Z offset. Layer shifting partway through a print Everything above a certain height is offset. Belts, grub screws or a speed the machine cannot hold. Nozzle clogged: partial and complete blockages A partial clog degrades quality gradually; a complete one stops everything. The cold pull handles both. Print detached mid-print and turned into spaghetti The part came off the plate and the nozzle kept extruding into air. Adhesion, warping or a knock. Ringing and ghosting on vertical surfaces Echoes of a corner repeating across the wall. Mechanical vibration the frame cannot damp fast enough. Stringing and oozing between parts Fine hairs across gaps. Moisture first, temperature second, retraction third — in that order. Supports that will not come off Supports fused to the part. Increase the Z gap and reduce the interface density. Under-extrusion: thin, gappy walls Not enough plastic is arriving. Partial clog, worn nozzle or an uncalibrated flow rate — check in that order. Warping: corners lifting off the bed Plastic shrinks as it cools and pulls the corners up. Heat is the fix, not adhesion tricks. Z banding: repeating horizontal lines up the print Bands at a regular pitch. Measure the spacing — it tells you which part is at fault.
Not a print defect? Error codes  ·  Calibration  ·  Filament
T1 Print defects Stringing, warping, first layer, under-extrusion 14 articles T2 Error codes HMS, MINTEMP, thermal runaway, homing failed 16 articles T3 Calibration Z offset, flow, pressure advance, input shaper 4 articles T4 Filament Temps, drying, enclosures, PLA vs PETG vs ASA 50 articles T5 Parts & fit Nozzles, plates, hotends — and what fits what 71 articles T6 Slicer OrcaSlicer, Bambu Studio, Cura, PrusaSlicer 8 articles T7 Upgrade & buy Which printer, which AMS, what fits your filaments 142 articles
HMS, MINTEMP, thermal runaway, homing failed

Error codes

All error codes →
HMS 0700-7000-0002-0007: AMS filament ran out A slot emptied mid-print. Load a new spool in the same slot and resume — the sequence matters. HMS 0300-2000-0001-0003: X axis homing abnormal, timing belt loose The belt is slipping teeth under acceleration. Tension it correctly — and correctly does not mean tight. HMS 0700-7000-0002-0001: failed to pull filament out of the extruder Unloading failed. The filament is gripped by something — a clog, a cold hotend, or a mushroomed tip. HMS 0500-0300-0001-0001: MC module malfunctioning The motion control board stopped answering. Restart first, then look at the cable that carries the link. HMS 0C00-0100-0002-0008: Live View camera image failed The camera stopped delivering frames, so spaghetti detection is off. Printing continues, but unmonitored. HMS 0700-2000-0002-0004: filament broken in the toolhead A piece of filament snapped off and stayed behind. It has to come out before anything else will load. HMS 0700-4000-0002-0001: AMS filament buffer signal lost The buffer that keeps filament tension no longer reports its position. Cable, sensor, or a spring stuck at one end. HMS 0300-0D00-0002-0001: heatbed homing abnormal The bed probe got an inconsistent reading. A dirty nozzle tip is the cause far more often than a warped plate. HMS 0300-3100-0001-0001: part cooling fan too slow or stopped The part fan is not spinning at the commanded speed. Debris in the blades and packed dust are the usual reasons. HMS 0300-2000-0001-0001: X-axis homing abnormal The toolhead did not reach the home position when told to. Something is in its way or the rail has gone stiff. HMS 0300-0100-0001-0007: heatbed sensor open circuit The bed thermistor is reading as disconnected. Nearly always the connector, occasionally the cable, rarely the sensor. HMS 0300-0200-0001-0003: nozzle heater over temperature The hotend went past its safe ceiling. Treat this as a real fault, not a nuisance warning.
Z offset, flow, pressure advance, input shaper

Calibration

All calibration →
01 Bed levelling and mesh compensation 2 min read 02 Input shaper and resonance compensation explained 2 min read 03 Flow rate and extrusion multiplier calibration 2 min read 04 Z offset: dialling in first layer squish 2 min read
Temps, drying, enclosures, PLA vs PETG vs ASA

Filament

All filament →
Nozzles, plates, hotends — and what fits what

Parts & fit

All parts & fit →
01 0.4 mm 3D Printer Nozzle: The Default Size, Which Thread Fits Your Hotend, and When to Change It 3 min read 02 3D Printer Cabinet or Stand: What a Good One Does for Print Quality 3 min read 03 3D Printer Nozzle Cleaning: Cold Pull, Needle, or Just Replace It 3 min read 04 3D Printer Camera: Official Add-On, Webcam or Phone, and What It Actually Catches 3 min read 05 IKEA 3D Printer Enclosure: Lack, Besta or a Cabinet, and How to Make Each Work 3 min read 06 SUNLU Filament Dryer: S1 Plus, S2 or S4, and Which Materials Each One Can Dry 3 min read
OrcaSlicer, Bambu Studio, Cura, PrusaSlicer

Slicer

All slicer →
01 Importing Cura profiles into OrcaSlicer 2 min read 02 Max volumetric speed: the real limit on print speed 2 min read 03 Infill patterns: gyroid, grid and when it matters 2 min read 04 Brim vs raft: which one and when 2 min read 05 Seam position settings that actually help 2 min read 06 Tree supports vs normal supports 2 min read
Which printer, which AMS, what fits your filaments

Upgrade & buy

All upgrade & buy →