Filament Extrusion Issues


Extrusion issues can manifest in a variety of ways, with several different causes. With a little troubleshooting and patience, they are usually easy to remedy. We have compiled some tips for solving some of the more common extruder problems to get you back up and printing. 

Before proceeding, please collect and record the following data: 

  • Gigabot number
  • Pictures or videos of your issue
  • .factory file
  • Filament type
  • Are you using a dust filter?
  • If the hot end is leaking, is it from above the nozzle or above the heater block?

A note on printing with PLA filaments:

Setting the nozzle to temps higher than 220°C when using PLA or leaving PLA filament in a heated nozzle without printing can cause the material to carbonize. This can create nozzle clogs that are difficult, if not impossible, to remove. When using PLA, ensure that the temperature does not exceed 220°C, and avoid letting the filament sit in an idle heated nozzle for extended periods of time. 

Jump to: Filament GrindingNo filament extruding from hot endInconsistent Extrusion

Filament Grinding

This occurs when the filament is unable to pass through the nozzle, resulting in the extruder drive gear shredding the filament instead of feeding it into the hot end. 

Possible Causes: 

  1. Printing materials with lower print temperatures in an enclosure.
  2. Using an outdated or incorrect printing profile. 
  3. Too much resistance is present in the filament tube.
  4. Inadequate tension settings on the extruder body.

Possible Solutions:

  1. Remove one or more panels from your Gigabot's enclosure.
    1. Some materials have a lower temperature threshold. PLA, PVA, and some wood or metal-filled materials do not require high heat settings when printing. A high ambient temperature within an enclosure can soften these filaments too much, making it impossible for the drive gear to catch the filament to feed it through the extruder. Removing one or more panels from your enclosure will ensure the ambient temperature stays cool enough for these materials.
  2. Verify you are using the correct and most up-to-date software profiles for your Gigabot.
    1. Your Gigabot model, firmware version, and hardware determine which profile you need to use. 
  3. Ensure that the filament tube is free and clear of debris or particles, and the filament passes through smoothly. 
  4. Verify that the filament is not bent in a way that would impede its progress through the tube. 
  5. Verify that the tensioner nuts are properly set
    1. The force of the bearing pressing against the filament allows the extruder motor drive gear to grip the filament and push it through the hot end. It is critical that the screws are properly set to apply adequate force to ensure proper extrusion.

If you are still experiencing difficulty after performing these steps, please contact re:3D Support or open a support ticket and include the following information:

  1.  A photo of the back of the Gigabot
  2.  A close-up photo of the filament detectors
  3. A photo of where the filament tube(s) connect to the print head

No Filament Extruding from Hot End 

If no filament is extruding from the hot end, it may be due  to one or more of the following causes: (Filament grinding may or may not be present)

Possible Causes: 

  1. The hot end cooling fan is not working (GB3/3+ or GB2 with All Metal Hot End upgrade).
  2. The hot end is too cold for the filament or print speed you are using.
  3.  The nozzle is clogged.
  4.  The J head PTFE liner has swelled (GB2).
  5. The extruder gearbox is defective.
  6. The nozzle is loose from the extruder assembly. 

Possible Solutions: 

  1. Verify the hot end cooling fan is active when the nozzle temperature is above 50°C.
    1. If the fans do not engage, you may need to replace them. Select GB2 or GB3 fans depending on your Gigabot model. 
  2. Verify the hot end temperature is set to the appropriate temperature for the filament you are using.
    1.  If you are printing at higher speeds, you will also need to adjust your hot end temperature, as the faster moves require faster melting of filament. 
  3. Install a dust filter, or replace a dirty dust filter.
    1. Dust or particulates may be preventing extrusion from the hot end. Using a dust filter or replacing a dirty dust filter will help keep your nozzle free of debris. Periodically check your filament filters to ensure cleanliness. If there is visible dust or debris built up inside, your filament filter needs to be replaced.


  1. If the hot end is reaching target temperature but no filament is extruding, performing a cold pull will most likely remove the clog in the nozzle.
    1. Trim the filament at the point where it enters the extruder. You will need to leave sufficient length to grab and pull the filament from the extruder in the next steps. 
    2. Set the nozzle to the printing temperature for the material you are using.
    3. Verify the nozzle has reached target temperature.
    4. Turn off the heat to the nozzle and monitor the temperature. The goal in this step is to catch the filament just as it begins to solidify. (Approximately 140°C for higher temperature filaments to 100°C for PLA filaments)
    5. Once the desired temperature is reached, firmly pull the filament from the extruder. This technique, when successful, captures debris from the nozzle and removes it via the filament. 
    6. Repeat this process until the filament pulled from the nozzle is free of any particulates. 
  2. The J head PTFE liner has swelled (GB2).
    1. The J head is rated for about 500 printing hours before the PTFE liner swells. If you are using a J head on a GB2, you will need to replace your hot end within this time frame. We recommend upgrading to the GB2 Metal Hot End. Instructions on this upgrade can be found here
  3. The extruder gearbox is defective.
    1. If the motors within the gearbox are not sufficiently lubricated, it can cause underextrusion. This is a factory defect, and the extruder gearbox will need to be replaced. Contact re:3D Support for assistance. 
  4. The nozzle is loose from the extruder assembly.
    1. If a gap is present between the thermal barrier tube and the nozzle, you may notice filament leaking into the threads. This indicates the nozzle has come loose from the assembly, and the hot end will need to be replaced

If you are still experiencing difficulty after performing these steps, please contact re:3D Support or open a support ticket.

Inconsistent Extrusion

Several factors may contribute to inconsistent extrusion during printing. 

Possible Causes: 

  1. The nozzle is partially clogged. 
  2. Your filament quality may be compromised. 
  3. Inadequate tension settings on the extruder body. 

Possible Solutions: 

  1. If you suspect a clogged nozzle, please refer to the cold pull instructions.
  2. If the filament is old, or has absorbed too much moisture from the air, it will affect the quality of your prints. Try printing with a different material to verify this is the issue. For more information on filament care and storage, please refer to Drying Filament.
  3. Are your tensioner nuts set according to this photo? The nuts should be at least halfway visible in the top window of the extruder body. 
  4. Slowing down the print speed to 3000 mm/min. 
  5. Print with the opposite hot end if your Gigabot has a dual extruder system.
  6. Adjust your layer height. (If the layer height is too small, it can cause inconsistent extrusion.)

If the above solutions do not work, please contact re:3D Support with the following information: 

  1. How many hours have you printed with your hot end and nozzle?
  2. Have you ever disassembled your hot end?
  3. Video of the print in action
  4. Photo of the extruder body (front and top view) 

Questions or concerns? Reach out to our support team at or open a support ticket

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