New U2 Startup Problem

[mike-truly 3]

I am a U2 newb and trying to setup the printer for the first time.

All was going fine til I got to the part about inserting filament into the feeder. As the print head was heating up, blue filament was coming out so I know it was heating and melting whatever remained in the print head.

I am using white PLA and inserted it into the feeder and it went in and up the tube and slowly made it's way through the tube to the print head. But NO white filament ever came out! It sounded like the feeder was having trouble getting the filament to move once it got all the way to the print head.

I chose a test print from the SD card and the printer went through the motions but no filament ever came out so I aborted the test print.

Not sure what I did wrong. HELP!

Thanks!

 

[IRobertI 520]

I've had this on quite a few printers lately. Usually it's a case of the filament getting caught on the edge of the white piece in the head (the teflon isolator). For that problem it usually helps cutting the end of the filament so that it's more a point (you can yank the filament back out when you power off the printer).

In other cases it's leftover PLA in the bowden tube getting bunched up as the new filament is being pushed in. It jams, again, right at the entrance of the teflon isolator. Sometimes it helps to pull on the filament as it is loading so that it skips back a cm or two and then let it feed again. Sometimes it helps by helping the filament along by pushing at the back of the printer.

In rare cases I've had to remove the bowden tube at the head and clean the old PLA out (very rare though).

 

[mike-truly 3]

Thanks very much for the ideas!

I got it sorted by removing the PLA (via the automated removal method) and then cutting off the grinded section of PLA (from the feeder knob) and cutting the end at an angle and then reloading the PLA. Now it works fine.

Did I really need to discard the grinded section of PLA? (I hate waste).

Thanks!

 

[IRobertI 520]

It's not super necessary to get rid of it but it could cause a slight bit of underextrusion in the print once that section gets to the print head. It is important that you cut away a bit of material though so that the grinded section doesn't end up in the feeder during a retraction (highly unlikely, but still) and starts grinding again.

 

[mike-truly 3]

Thanks for the info!

I think I may be confusing what is 'grinded'.

I definitely needed to cut the end at an angle to help the feeding into the print head... but the grinding I was talking about is basically the tiny knurled pattern on the PLA that I can see through the tube. And that is always being fed to the print head, so I probably could have just cut the end and left that bit? Or is that tiny knurled pattern what you mean by grinded?

Thanks again.

 

[IRobertI 520]

Scroll down a bit on this page and you'll see an image of what grinding looks like:

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide

So grinding is when the knurled sleeve (the bit that drives the filament forward) digs a hole in the filament. The teeth marks are fine to leave, those are no problem at all.

 

[mike-truly 3]

Thanks very much for that link! I understand now.

Thanks again.