Cleaning filament stuck in print core

[ahonma 1]

We were performing a print core cleaning on an Ultimaker S5 with Ultimaker's cleaning filament (which we do routinely every few months), and the cleaning filament has become stuck during a hot pull. 

 

What we've done:

• Start a print core cleaning
• Performed one hot pull with Ultimaker's cleaning filament; tip was not clear/clean
• Cut tip of filament
• Started to perform a second hot pull with Ultimaker's cleaning filament
• When trying to pull after 1-second insert, filament would not come out, to the point the entire S5 would have lifted off its table if we'd pulled harder with our pliers

 

Print core: AA 0.4

Stuck filament: Ultimaker Cleaning Filament

Printer: Ultimaker S5

 

Any suggestions on how to remove the stuck cleaning filament?

[gr5 2,176]

In the middle left menu, click on the left or right filament (depending which you need to get out) and then select top right "..." and then select "MOVE".  This is one of 2 ways to heat the core from this menu.  Wait until the temp is above 120C and start pulling.

 

Make sure the print head is in the corner so you don't bend the rods.  It's okay to lift hard enough to lift the printer off the table.

 

If that doesn't work, leave it at full temp for a full 2 minutes and try again.  Sometimes the filament gets into cracks above the heat break.  This is rarely a problem but sometimes.  If this happens a lot then replace the core as it probably has a defective piece of teflon in there (sometimes it's cut too short and there's a gap for filament to get into).

[gr5 2,176]

Only once, I had to take apart the core.  You can use a hot knife to slice off the filament above the "trumpet" (top) of the core, then slide out the core, power of the printer and disassemble the core.  On youtube search for "um3 core disassembly".  But I recommend instead just buying a new one.  They are considered "consumables".  Like filament but cheaper since they last much longer.

[ahonma 1]

We tried manually heating the print core, but that didn't work, and then we tried starting the print core cleaning process again, and it popped right out with almost no effort when prompted to do the first hot pull. So...not really sure exactly what ended up being the solution, but I'm going to mark this as resolved.