wall not flat

[tomnagel 126]

I created an object to hold 3 small jars with spices for use in a kitchen cabinet.

I noticed that the flat sidewall is not very smooth for the first 20mm height, which corresponds to the height where the 3 circles stop. Above 20mm (where only the wall is printed), the wall is silky smooth. What the picture also shows, is that the not-smoothness is on one side (right side in the picture), and not on the other (left side).

Does anyone have a clue about the cause of this non-smoothness?

[yzorg 9]

On my machine i have this "grippy-surface" problem too.

your lucky to have this on the invisible back side :mrgreen:

first i though it was intolerant filament. because other layers come out perfect like yours..

it tends to settle only on outer walls that have other geometries right next to it. (thin walls too)

i didnt found a way to have it solved but printing very slow... and thats not realy a solution.

[Daid 306]

We're suspecting that it's an over-extrusion problem. Lowering your "infill wall overlap" might help. (Needs more testing, we have a model that shows this effect a lot worse)

[tomnagel 126]

Would it help to give you the gcode file? Because something must be happening there? I mean, I find it hard to believe that the nozzle is running at one speed, with constant extrusion.

[siert 0]

Hi Tom,

Please send the gcode. I have been thinking about it, and I agree with Daid, that it is probably an overextrusion. I have attached a picture which shows it even worse.

This object is single wall, with a few letter on the top.

In my opinion in this picture it has to do with the infill of the U.

Siert

[tomnagel 126]

I'm pretty sure this is not the same. I had the same with another version of my spice jar holder, where the wall of the rings was so thin it only contained 1extrusion. After I printed this, I had *exacly* the same effect.

Later I noticed that I could have seen this in Cura before printing: there are lot of blue lines right around the rings. When the head moves along these line, there is little extrusion, causing the rough outside.

I bet that the model you are showing in your photo also has these blue lines in Cura.

The model that I started this thread with, does not have these blue lines, the rough effect happens during printing. Maybe the cause can be found in the Gcode file, but I have not yet studied it. I will send it to you.

[joergen 2]

I had seen this quite often, but only with cura/SF code, never with any of the other slicers... it may be speed related, when the outside skin is printed faster/too fast, and the extrusion can't grip onto the lower layer... it is somehow the same effect that you see if you print regular (not hex/honeycomb) infill too fast... printing fast in midair will cause crumbly/useless infill. alternatively, it may be that the nozzle is too hot, and not enough cooling is happening (combined with to much speed). iirc, this effect happens more often on the side away from the fan, and not on the fan side.

the other solution would be that you are severely under extruding. cura is set to the default 2.89mm filament diameter... but it is very unlikely that your filament is actually 2.89mm, you may be extruding filament that is only 2.7mm, which would cause a similar effect.

[tomnagel 126]

Please note that the blue lines are movements from the extruder head which are not supposed to yield any extrusion. So "transport only".

[wemperor 0]

Did you found any solution for the problem? I´m facing the same issue on a lot of prints and would be happy to get rid of it.

[tomnagel 126]

I redesigned my object, so there are no longer single walled parts. That did the trick for me, but at the cost of more plastic.