Retracting after print is done

[r2deco 0]

Hello,

I am having an issue with my Ultimaker 2. After it finishes printing it retracts the filament a little (I assume so it doesn't get hard in the print head when cooled) and it has a bulbous head of melted PLA on the end of the filament. If I try to print again the bulbous head can't fit through the PTFE coupler and the feeder keeps clicking. I end up removing the bowden tube and clipping the end off with a pair of pliers. It then enters with no problem. Has anyone experienced this? I don't know if it is retracting too much and I can somehow adjust this or is the bulbous head caused by a bad PTFE coupler? Please help.

[gr5 2,071]

I don't get the bulbous head. Is your bowden tube all the way down? Not UM2+, right? You should be able to see the bowden through the spring and tell if it's all the way into the white teflon part. If it is well seated then I'd guess it's your ptfe coupler. How many hours have you printed on this coupler (you can check in the menu system for hours printed if that helps) and what temperatures do you usually use (max) for prints that are on the high end of the temperature spectrum for you?

[gr5 2,071]

I'd raise the bowden until you can see the end of it and make sure it goes down another mm or so *into* the teflon part.

[r2deco 0]

I never looked at the hours printed. That's cool, thanks for letting me know about that feature. I'll check it out. Last night I removed the PTFE coupler and it looked bad. I think you were right, my coupler looks deformed on the top and was not allowing the bowden tube to insert all the way. I'm ordering a new coupler today.

[gr5 2,071]

Order it from my store then: gr5.org/store/