prints don't have a smooth top layer

General Software
1

I am using cura to print and I have had a lot of success using the default settings for my cheetah flex but recently it has changed, the infill is sloppy yet the outer layers are smooth however the top layer is all lumpy and full of holes. I do not know weather it is a hard ware issue or a cura issue but I would assume that if it was a hardware issue the outer layers would not be smooth but on the other hand I have not changed any of my cura settings so I don’t know why that would be a problem now. i have tried other cura settings and have bumped the infill to 30% and slowing the print down but still I get these gaping holes

IMG_1960[1].JPG
IMG_1960[1].JPG3264×2448 1.02 MB

IMG_1959[1].JPG
IMG_1959[1].JPG3264×2448 1.51 MB

IMG_1961[1].JPG
IMG_1961[1].JPG3264×2448 1.26 MB

2

I have had luck making the top layer wider. IIRC on a .50 ABS profile I made the top layer width about 25% greater than default with decent results.

3

Yeah… maybe a few more top layers.

4

thanks for the suggestions. I have tried more top layers already but, I am having a problem with the infill as well as the top of the print so that leads me to think it is the sloppy infill that is the problem with the top of the print.

IMG_1962[1].JPG
IMG_1962[1].JPG2448×3264 1.93 MB

IMG_1963[1].JPG
IMG_1963[1].JPG2448×3264 1.26 MB

IMG_1964[1].JPG
IMG_1964[1].JPG2448×3264 1.26 MB

5

Yes… that looks like the hotend is being starved of filament. Check that the filament is coming off the spool smoothly… and possible tighten the idler screws by a turn or two.

In theory, more top layers will build up and reduce any issues with infill… I print a lot of prototype parts, and use .3mm layer height with 3-4 top and bottom layers. Doing the math, that’s .9mm and 1.2mm respectively.

6

To me, it looks like your getting some under-extrusion. Check to see if your filament is grinding at the hob bolt. You might be getting a partial clog. You might try increasing the nozzle temp a bit or increase the flow a bit. Also measure your filament diameter with a caliper to make sure you have the right diameter set in Cura.

7

so if its under extrusion then why are the sides so smooth it seems as if the sides are extruding just fine.

8

the filament feeds just fine but it might be the speed at witch the head is going, so I will look into that next.

9

i’m ok with this idea “try increasing the nozzle temp a bit or increase the flow a bit”