Weird extrusion problem

[ultijoe 0]

Hi !

I currently have a weird extrusion problem on my Ultimaker2. I have had extrusion problems before but this one is hard to figure out.

I get very nice bottom surfaces but quite a few errors on the sides. Also the top layer is incomplete. What makes this weird is that test cylinders turn out fine. The only (also weird) problem I had with those is some errors on the lower speeds. I collected some sample pictures in the following link:

https://dl.dropboxusercontent.com/u/56394125/ulti.png

I am thankful for any hints and tips !

 

[pm_dude 26]

Hi Joe,

Welcome to the forum.

Can you please provide some more information in regard to your print settings? temp, speed, layer height? Also can you tell the printing time so far with your UM2? You can find that info in the advanced menu on the UM2.

Its probably a partially clogged nozzle. Have you tried doing the atomic pull (also know as cold pull) method a few times?

 

[ultijoe 0]

Hi,

I have tried teh atomic pull several times. And while it did help with previous problems, it does not this time.

The layer height is 0.1mm speed is 50mm/s and the temperature is 210°C.

The printing time is 900 hours and close to 1km of filament was printed during that time.

I had a similar problem before, which turned out to be a "worn out" insulator. I replaced it at everthing worked again until now. Back then, however, I noticed the feed skipping and also had extrusion problems on the bottom layer. Now the first few layers are always fine.

Also, shouldn't i run into problems with the cylinders if the nozzle was clogged ?

Thank you !

 

[tinkergnome 631]

...

Also, shouldn't i run into problems with the cylinders if the nozzle was clogged ?

...

 

It appears to me that the test cylinders are also far from perfect...

...but the reason is not necessarily a clogged nozzle.

I would check the attachment of the bowden tube - is all tight (especially during retractions)?

Next: potentially an issue with the z-screw...?. Is it clean, well lubricated and moves smoothly?

Important: use only the included grease or something similar for the z-screw.

 

[ultijoe 0]

That is interesting. Could you elaborate on the cylinders ? My understanding was that at least the rings from the 4th on were perfect. The z-screw is well lubricated with the supplied grease. I will check the bowden tube now. Thank you!

 

[tinkergnome 631]

That is interesting. Could you elaborate on the cylinders ?

These extrusion patterns look pretty similar to me. Perhaps the visible "under-extrusion marks" even are on similar z-heights...?

That's why i had the idea with the z-screw...

 

[ultijoe 0]

So I took the printhead apart and it turns out it was the PTFE coupler. It was a little burned/deformed. I had this problem before and replaced the part just about a month ago. Any idea what could cause this part to wear off (abnormally?) fast ?