Step-by-step guide to troubleshooting problems in material extrusion

From Maker Trainer, the online makerspace

Material extrusion, also known as Fused Deposition Modelling (FDM) and Fused Filament Fabriacation (FFF) is one of the most widespread modes of 3D printing in the world due to its low cost and versatility. The concept of material extrusion is relatively easy to understand, which makes it a good point of entry into maker hobbies. In practice, the process has many variables, including software settings, adjustable moving parts and hardware pieces which are prone to deterioration or clogging. The large number of variables can make troubleshooting an FFF 3D printer's issues difficult. The same issue could arise due to multiple different causes, and one cause could result in multiple different issues. The quality of the 3D printer and the filament can also have a strong bearing on the end result of a print.

The guide below goes through the steps of 3D printing, and describes issues that might become visible at each step. The issue is not necessarily caused by something done at that step by the user, the cause could come from earlier in the process but only manifests itself at the described stage.

(Note: This list is not exhaustive, and is only advisory, not instructive. The respective manufacturer should always be consulted for the most accurate information and support for a certain machine.)

Issues encountered in slicer software

Unable to load or slice 3D model

See 3D model

Issues encountered while turning on 3D printer

The 3D printer does not turn on

Cause: Improper power supply

  • Disconnect and reconnect the power cable on both ends to make sure it is connected well.
  • Test the power outlet with a different electronic device, or change power outlets.
  • Use a different power cable.
  • Check for a blown fuse on the power supply or main board.
  • Some 3D printers have an adjustable voltage switch (110V/220V). Make sure it is set to the same voltage as the power outlet.
  • Replace the power supply component.

Cause: Faulty wiring

  • Disconnect from the power supply and check that all wires are properly attached.

STEP-BY-STEP: How to fix a 3D printer that does not heat up

print head, bed or chamber

1. See which component is not heating up.

You should be able to see the temperature of each heatable component on the 3D printer's built-in status screen.

2. Check if all the components that are set to heat up are capable of doing so.

Many 3D printers do not have a heated bed or a heated chamber. If a temperature is set in the G-code for a component that cannot heat up, the printer might be stuck in a perpetual state of trying to heat up.

You can find out which parts are heated by consulting the manual. If a component has its temperature displayed on the printer's status screen, it is also a good indication that it can be heated.

Check the temperature read-out before trying to heat up.

Components should be at room temperature if the 3D printer has not been used for a while. If the read-out is unusually low (eg. between 0-5°C), it means there is a problem with the thermistor. Make sure the thermistor is properly attached on both ends. If it is securely connected and the issue persists, try changing the thermistor.

Note: there should be a thermistor for every **heated** component on the printer. This includes the hot end (or hot ends oif there are two or more extruders present) the heated bed (if applicable) and the heated chamber (if applicable).

Try heating up the components using the printer's firmware. If the heating does not start, there might be insufficient power going to the printer. Link to power supply

Try loading a different G-code onto the printer.

If the printer is able to heat up using another G-code, the problem lies with the file. Try re-slicing the the 3D model, or try slicing it in a different program, making sure your components can reach the temperatures you set.

Faulty thermistor

3D printer heats up but printing does not start

Cause: Corrupt G-code

  • Try printing a different 3D model, and see if the problem persists.
  • Re-slice the 3D model.
  • Try delivering the G-code to the 3D printer in a different way, eg. different SD card or Wi-Fi. Try copying the G-code directly onto the 3D printer's hard drive to avoid disruptions.

Cause: Required temperature is not attained

  • Check if the 3D printer has achieved the nozzle, bed or chamber temperatures set out in the slicer software. If the G-code requires a temperature higher than what the 3D printer is capable of, the printer might get stuck trying to heat up indefinitely. Many 3D printers do not have a heated bed or heated chamber, in this case these settings should be disabled or set to 0.

Printhead moves but does not extrude anything

3D printer keeps asking to load filament

Cause: Faulty filament sensor

Switch of your filament sensor via : Settings->Fil.sensor (off). Load he filament to the extruder via command : Load filament Start printing - if it starts ,then you have issue with filament sensor. Check the cabling - whether you Filament sensor cable is in correct plug position and correctly oriented (both counts - read again carefully the assembly manual especially the filament sensor connection)

Your filament sensor may be incorrectly mounted.

Make sure the magnet is turned in the right direction and that the FS liver can move easily.

Also, make sure the sensor cable is properly installed.