Ultimaker 3 Chewing Up PLA Filament/Not Printing

[pdihawk 0]

I have an Ultimaker 3 and I am having problems with one of my print heads not extruding.  Both extruders are AA 0.4.

Print head #1 still works great with an ABS filament.

I have Ultimaker PLA in print head #2.  It will print well for a while and then stop extruding completely and the filament is chewed up in the feeder.  I unloaded and reloaded that filament and couldn't get it to work.

I changed to a different color and it worked for two prints but stopped again with the same symptoms.

 

I've blown out the Bowden Tubes and feeder with compressed air and cleaned the nozzel but nothing seems to help.

 

Why would it stop extruding and chew up the filament in the feeder?

[gr5 2,094]

Do you have the S3 or the UM3 as your other post mentions the S3.

 

 

[pdihawk 0]

I'm sorry, it is a UM3.  I was mistaken in the other post and caught my error in this thread.  On the front, it says "Ultimaker 3".

[Smithy 1,141]

Check if the middle fan on the front is working when you heat up the print cores.

[gr5 2,094]

@pdihawk - chewed up filament can be caused by dozens of very different issues.  For one thing it can be caused by the feeder or the hot end.  If the hot end is underextruding the feeder is fighting hard and doing it's best and chewing up the filament a little bit but at some point it gets out of control and bites out a circular chunk and nothing comes out.  So it can be either end.

 

Usually it's the print core.  But it could be your feeder is at the wrong tension.  Look at both feeders and the tension indicator should be in the middle for PLA.  If the tension is too low it can slip more and chew up the filament.  It could also be that you ran CF filament through feeder 2 but that is unlikely.  CF filament can smooth down the tiny pyramids that grip the filament.

 

More likely it's something about the nozzle.  I'd try some cold pulls - you can do these from the front panel control on the printer.  It will give you instructions.

 

Another thing to try is to just change out the print core.  This is the solution that takes the least amount of time and effort (but the most money).  Ultimaker considers print cores a "consumable" just like filament.  Even if you bought one core every 5 spools of filament it wouldn't be all that significant of a cost.

 

[pdihawk 0]

Got it!

 

As long as it has been at our company, it hasn't had CF filament run through it.

 

I unloaded the PLA on #2, removed the chewed up section and reloaded.

 

I started an almost 3 hour print a little bit ago.  The middle fan is spinning and I will see how it goes.

 

If it keeps having problems I will try the spare print core that we have.

 

Thanks for all of the help!!

Edited August 12, 2021 by pdihawk