Failure to Extrude at the Start of a Print

If your 3D printer isn’t extruding plastic at the start of a print, don’t worry— this is a common issue, especially for new users. Fortunately, it’s generally easy to fix.

Common Causes and Solutions:

Nozzle Too Close to the Print Bed

If your printer's nozzle is positioned too close to the print bed, there may not be enough room for the plastic to extrude properly. If this is the cause of the issue, no plastic will be extruded during the first few layers. However, as the nozzle moves further away from the bed in subsequent layers, the extrusion will start to work. To fix this issue, use the Z-axis G-Code offset feature in your slicer’s settings. This allows you to make small adjustments to the nozzle height without modifying the hardware. Start by increasing the offset by 0.05mm increments until there is enough space for the plastic to flow.

Extruder Not Primed Before Starting the Print

When left at a high temperature, extruders may leak plastic which can create a gap inside the nozzle. This can occur when preheating the extruder before starting a print or after finishing a print when the extruder is cooling down. If plastic has leaked out, it may take a few seconds for the filament to flow again when you next start extruding. To avoid this, prime your extruder just before starting a print. You can do this by adding a skirt in your slicer software, which draws a circle around your model and helps fill the nozzle with plastic. If extra priming is needed, increase the number of skirt outlines. Alternatively, you can manually extrude some filament before starting the print.

Filament Stripped by the Drive Gear

Most 3D printers use a small gear to feed filament through the extruder. If you notice plastic shavings or a section of filament that appears damaged, the gear may have stripped too much material from the filament. Once the gear can no longer grip the filament, extrusion will stop. Refer to the Grinding Filament section for guidance on resolving this issue.

Clogged Extruder

If none of the above solutions work, your extruder may be clogged. Clogs can occur if debris gets stuck in the nozzle, if plastic remains in the extruder for too long, or if the extruder’s cooling system isn’t sufficient, causing the filament to soften prematurely. Fixing a clog may require disassembling the extruder. As a result, we recommend contacting your printer manufacturer for guidance before proceeding. In some cases, a thin wire can be fed through the nozzle to help clear the clog. Your manufacturer may also have other specific recommendations for unclogging your extruder.