Extruder Nozzle Scraping Previous layer..Is this normal??

[mfknjohn 6]

I have been printing about a month now on my Ultimaker 2 Extended, I had a rough start but am currently happy with my settings. After printing a few Prototype parts everything comes out well, although after switching to my Green UPET (CPE) filament from ultimaker I see little scrapes in the previous layer printed where the nozzle went over the layer? Is this normal or am i TOO close to the bed? It doesnt really affect the part or the outside but I was just curious.

[ghostkeeper 105]

It's normal to have some scraping if the layer height is low. It's usually a good thing, actually. The second time the nozzle goes over the material, it smoothes out the layer a bit more, just by pushing hot filament on top of it.

From what I can see in your picture, it is probably scraping too much though. Too much scraping is bad though since it will result in an uneven outer surface (as well as the inside). If you see that the wire is flattened such that it becomes wider, you should probably adjust the bed a bit lower. During the bed levelling, make sure that you can put a normal 80g-weight paper between the bed and the nozzle, and that you can feel just a little friction with the nozzle when moving the paper underneath.

Edited June 12, 2015 by Guest