Flat surfaces won't print properly

[PBJ-Designer 0]

Hi there!

I've been having a bad time printing recently, my prints come out with really nice sides as always, but the flat surfaces are horrible!

It's almost like it doesn't print a finishing surface on top of the infill.

I've been trying to figure out what the problem could be, but even when tweaking cura and following different forum threads with problems similar to mine, I haven't been able to solve the issue!

My cura settings are:

layer height: 0.1

Shell thickness: 0.8

Bottom/top thickness: 2

Fill density: 40

Print speed: 70

Nozzle size: 0.4

Initial layer thickness: 0.0

Initial layer line width: 100

Cut off bottom: 0.0

Dual extrusion overlap: 0.15

Travel speed: 150

Bottom layer speed: 20

Infil speed: 80

Top/bottom speed: 0

Outer shell speed: 30

Inne shell speed: 60

Expert configuration:

Solid infill top: yes

Solid infill bottom: yes

Infill overlap: 15

Infill prints after perimeters: yes

I'm hoping someone knows what to do here.

[jameshs 42]

Hello,

with that infill I would recommend that you do bottom layers of 4 and top layers at least 6

you don't say what you are printing with or temp, but at that speed the temp would need to be quite high to get the speed.

James

[Nicolinux 269]

Hi,

these setting is problematic and should not be set to 0

Initial layer thickness: 0.0

Could you take a photo from the side. Are there gaps too?

[PBJ-Designer 0]

Im printing with PLA, and I haven't changed the temperature, so that's the standard temeperature for PLA

[PBJ-Designer 0]

There are no gaps in the side construction, that's all nice and solid. It's only the flat surfaces that fails every time

[jameshs 42]

but you are not trying to solve the sides!

agree that initial layer needs to be 0.3 or something like that, and then drop the speed, and up the No of layers - if it does not work then come back!

think about squeezing out toothpaste - slow and it has time to come out of the tube in a line, too fast and it will smear and break up.

then think of smearing the tube on a sieve - the first few layers will fall through, but after a few there will be enough on underneath that it forms a good solid layer - this is what is happening here - you are a) bridging across the infill and b) going too fast (imho) not to smear.

Have a go!

[PBJ-Designer 0]

Hi James

I lowered the speed to 50 and set the layers to 0.4, and now it works great!

I would however like some more solid layers, some of the smaller flat surfaces still have a very thin - almost non existing - surface which is juuuust connecting the surface with the rest of the print.

How can I fix this - In my 3D model, the thickness of the material i 3 mm, but those darned flat surfaces seems to be proving a great amount of distress...

[jameshs 42]

Great to hear!

bottom/top thickness - needs to be at least 6 - you have only 2 and that is not enough to give a solid covering over infill.

James