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Filament Stops Extruding Mid-Print

· 4 min read
Pranav G.
Pranav G.

Filament Stops Extruding Mid-Print​

What Is It?​

Your 3D printer can stop extruding filament mid-way during printing, leading to a failed print and losing printing time. The most likely and apparent reason might be your printer running out of filament material.

But, in some cases, nozzle clogs and defective extruders too can be a potential issue.

What to Check?​

  • Filament Spool
  • Printer Nozzle
  • Extruder assembly
  • Stepper motor temperature

How to Fix it?​

Reload the Filament Spool​

First, you should inspect the filament spool of your 3D printer. If the material runs out, you need to install a new spool and resume printing.

However, if you notice filament knots or tangles in the spool, you'll need to unwind the filament spool by cutting the material at one end. If the knot is too complex, the best solution is to cut the filament knot and reload the material once again.

Alternatively, it'd be helpful to install a filament sensor if your 3D printer supports it. The sensor will immediately pause the print and prompt you to reload a fresh filament spool. It comes in handy when you're continuously executing long-duration 3D prints.

Clean the nozzle​

A nozzle clog can build pressure in the hot end and eventually lead to a leaking hot end. In some cases, it can even create a hot-end blob, potentially ruining your entire hot-end assembly.

A quick way to clear a nozzle clog is using a nozzle cleaning needle. It's easy to use and can quickly remove small particles stuck in the nozzle's orifice. However, it'll merely displace the impurity/dust particles within the nozzle. It doesn't altogether remove the impurity, and you can experience a nozzle clog again if the particle blocks the nozzle's exit.

Another method to effectively remedy a nozzle clog is cold pulling. The technique involves heating the filament to its melting temperature and then cooling it. You need to pull the filament as it's transitioning from a molten state to a solid state; you should experience slight resistance while pulling back the filament. It traps the impurities along with the filament and thoroughly cleans the nozzle.

However, if nothing works, the best and easiest way is to replace the faulty nozzle with a new one. Brass nozzles are cheap, and this solution is a guaranteed way to get rid of a clogged nozzle.

Replace Faulty Extruder Components​

Cracks in the plastic extruder arm or flat spots on extruder gears indicate worn-out components. In this condition, the extruder assembly isn't able to grip the filament adequately, causing the filament to slip within the extruder. It leads to under-extrusion and, in some cases, might completely restrict the filament flow to the hot end.

The best solution is to install a readily available metal extruder or get a high-end extruder such as the Bondtech one. It will ensure a firm grip on the filament and won't get worn out easily.

Cool Down the Stepper Drivers and Motors​

Stepper motors and drivers tend to heat up when you're continuously printing for long hours. Specifically, the extruder motor works more than the X and Y drives due to the constant retraction and extrusion cycles. If the operating temperature exceeds a specific range, the driver will automatically cut off the current, pausing the stepper motor.

You'll need to let the motor and driver cool down before resuming the print. An excellent way to prevent this scenario is to ensure sufficient ventilation in your 3D printing space. You can install heat sinks on the stepper driver and motor to quickly disperse the heat from these parts.