Dots and some stipes - Bad quality in 0.2mm layers

[jangermann 13]

Hi

I´m new to UM2 but not 3D printing.

I have been printing in 0.08mm and 0.1mm layers without any problems.

Last night I was printing in 0.2mm and got some nasty dots and some stripes.

The printing conditions:

-Ultimaker PLA

-Filament 2.85mm

-Speed 25mm/s

-Hotend 200deg

-No infill

-Wall 0.8mm

http://germann.dk/webbilleder/um1.jpg

http://germann.dk/webbilleder/um2.jpg

Any ideas?

hope you have :-)

 

[francfalco 39]

I too have same issues with my UM 2 - prints great at 0.1/0.06 but at 0.2 i have issues similar to yours?

i've tried to find a solution - lower speed, retraction, acceleration, try new slicer (you are using Cura yes?).

I had a slight improvement going back to an older version of Cura, but so far i have not been able to eliminate them completely. I could be wrong but it seems Cura has slicing issues with its 0.2 settings - others have mentioned this also - but i'd love to be proved wrong?

If you do find a solution please let us know

 

[jangermann 13]

I have now printed the same model in 0.15mm layers, it is much better, but I still see the dots. They are smaller now but still visible.

In 0.1, and if I look really close, I also see the dots. Even in 0.08mm I see micro dots.

It seems like the problem always is there, but with smaller layers you get smaller dots.

Yes I am using Cura V14.09

 

[phil-t 0]

From my own brief experience, I've found the Ultimaker PLA doesn't flow so well at 190-200C on my UM2 and I was getting the same issues.

I think some of it is learning your own printer and whilst doing a few solid infill prints, I took the opportunity to play with extruder temperature and material flow rates with speed, I've found for my machine upping the temp of the extruder closer to 230 seems to make for neater infill lines, and a material flow of 110% seemed to also improve the infill consistency, with that done, I've been happier with 0.2mm layer prints now.

There is definitely a necessity to 'understand' your printer and each material, I do small tests while printing more uniform parts using the tune menu to see the effect and try to arrive at a happy set of values.

 

[jangermann 13]

I have now tried to change filament to a non ultimaker filament and also changed the diameter to 2.90 (measured on the filament), and played with the temperatures, it don't change anything.... same problem with dots.

BUT when I now print in 0.2mm after filament change, I see the dots again, but as small holes. Before when printing with the ultimaker PLA the dots were popping out, as too much material.

I think it's time to play with the flow rate.

 

[pm_dude 27]

The lines in picture 2 looks like under extrusion to me. The dot are potentialy retraction points where the head left the model to reach somewhere else.

 

You can verify that in Cura in the layer view. Go to the layer that has a dot and see if there is a blue line (toolpath line with not extrusion).

 

[jangermann 13]

PM_dude thanks for your answer. When I print the model there are no retraction.

The dots come every time a layer is finish, where it join the inner perimeter with the outer perimeter.

I have now tried adjusting temp,flow,speed, and still the same result. Very visible dots when printing 0.2mm layers :sad:

This is simply NOT what I was expecting from my brand new ultimaker2 :???:

Pictures after filament change.

http://germann.dk/webbilleder/dots1.jpg

http://germann.dk/webbilleder/dots2.jpg

 

[jameshs 42]

try spiralise - which will let you know if it is a random zscar.

 

[jangermann 13]

I can see while printing, when the UM2 makes the dot.

http://germann.dk/webbilleder/dotpoint.jpg

Maybe the dots cant be avoided??

Are all here experience dots as in the links above?

 

[Dim3nsioneer 558]

Try reducing the print speed...

 

[DidierKlein 729]

This is the Z-scar:

http://support.3dverkstan.se/article/30-getting-better-prints#z-scar

Except on your model it's seems random but the cause is the same

The latest version of Cura tries to find places to start the line where they are going to be hidden... (like corners) but with organic shapes i guess it's hard to hide

In order to limit this you have to limit oozing by printing slower and probably by printing at the lowest printing temperature acceptable.

Or try with another slicer?

 

[jangermann 13]

Thansk for your answers.

Ok, so the Z-scars on my model is normal?

Do yours also do this?

Please note that this is "only" a problem when printing above 0.1mm layers. Below that, the scars is very small and barely noticeable.

 

[DidierKlein 729]

Yes mine does to. I think it's more related to the slicer than the printer, but it can be reduced with tuning the speed and temperature

 

[jangermann 13]

Ok. Thanks again for all your answers.

[LePaul 354]

I get that with my Ultimaker Original when trying to print closer to 200C. For my printer, it seems like the best temperature is 208-210 for most of my prints Most of what I print is small stuff with high detail (little statues for my friend's kids). I've tried printing at the lower temps based on the pictures of stringing I have seen at higher temps and faster speeds....but find a few degrees warmer works best on my printer using Ultimaker silver pla filament

Good luck!

 

[gr5 2,270]

The horizontal lines look like underextrusion or maybe Z issue. Underextrusion could be caused by the nozzle cooling temporarily by 10C or if the filament tangles and requires much more force for the feeder.

Z issue will sometimes occur at the same spot on multiple models due to some problem with the Z screw or the Z bearings.