Zortrax M300 Plus not extruding/underextruding

Hi, we have a M300 Plus that recently started having some big extruding issues.
Main issues are:

  • after printing 1/3 of the piece the extruder stops feeding (not sure if the extruder motor stops spinning or not) and the printer goes on printing nothing in the air.
  • general underextrusion on parts ( weak supports, outer wall separated from inner walls and infill, imperfections, weak layer adhesion. We are printing with external material Easyfil PETG that we already used many times.

The other day we stopped a print that was meant to be 20h because it had been printing in the air for many hours (don’t know how long cause no one was in the office). Im starting to think that the extruder morot was not spinning because otherwise we’d have a lot of filament grinded around the feeding wheel and there’s none. This exaxt scenario already happened many times during the last 10 days.

What we tried to solve this problem:

  • change the nozzle
  • change filament
  • check for nodes in filament spool
  • execute unclogging procedure
  • re-level the bed
  • downgrading firmware to the previous version as the beginning of the issues is around the day we updated to the newer version
  • check the feeder bearing
  • try different version of Zsuite (current and beta)
  • reconnect extruder cables
  • check nozzle temperature with external thermocouple and heat camera (ok)

Here’s a video of the last print that failed right before we stopped it ad some photos of the pieces that came out of it.



Do you think the problem is electrical or mechanical? What could we do to find out the reason this is going on and solve it?

Thank you

Hello Andrea,

When the printer stops printing please make sure to check if the motor is skipping or not moving at all.

It could be a problem of extruder cable or extruder PCB.

Does the loading material process go smoothly all the way?

You can check the cable, by bending the extruder cable in different places/angles while loading the material to see if it starts or stops skipping, but for starters please check if the motor is moving at all when the extruder has stopped extruding.

Best Regards