Top Layer Issues

Get answers & advice for all of your 3D printing & Free Software needs here!
Post Reply
TomsCables
Posts: 78
Joined: Mon Apr 14, 2014 8:45 am

Top Layer Issues

Post by TomsCables » Thu Sep 27, 2018 10:25 am

Hey All,
I have a very simple print that is driving me nuts because I cannot get it to have a smooth top layer.
It appears the infill is collapsing and causing holes in the top layer.
I have attached the stl file.
earl 2.jpg
Cura 21.02
I have tried setting the nozzle temp down from 270 to 240 to 245 (I'm printing with ABS)
I have tried adjusting the filament diameter from 2.85 to 2.87 to 2.83 made no difference.
I have tried adjusting the printing speeds for the Infill and top layer currently running at 15mm/s

The only way I was able to get a successful test print was to up the infill to 85% (It was at 40).
earl 2.jpg
Cura 21.02
Cura 21.02 3.5mm nozzle 40% infill 270C 100C bed. 2.85 Dia filament


Cura 3.04 3.5mm nozzle 40% infill 270C 100C bed. 2.85 Dia filament Irioning enabled.
earl 2.jpg
Cura 21.02
Cura 21.02 2.87 and 2.83 filament dia Printing speeds decreased.
earl 2.jpg
Cura 21.02
Cura 3.04 3.5mm nozzle 85% infill 245C 100C bed. 2.85 Dia filament Irioning enabled.

Its a little hard to see in the photo, but the top layer of the plastic drops between the outside perimeter and the inside perimeter of the fat part of the E.

I've never had the printer have issues with the top layer before so I'm a little stumped as to what to do. When examining these parts under magnification you can see the extrusion has a zigzag edge, and that it doesn't appear to touch the edge of the previous extrusion.

I'll also add the walls are perfect, no missing spots or bulges.
Dimensionally the prints are coming out correct also.

I'm stumped.


For some reason, the Forum keeps deleting my attached pics.
Attachments
earl 5.jpg
Cura 3.04 85% infill.
earl 4.jpg
Cura 21.02 2.83 and 2.87 filament diameter
earl 3.jpg
Cura 3.04 Ironing Enabled
Earl.stl
STL File
(70.39 KiB) Downloaded 1 time

kcchen_00
Posts: 1608
Joined: Thu Feb 19, 2015 12:42 am

Re: Top Layer Issues

Post by kcchen_00 » Thu Sep 27, 2018 11:16 am

Try increasing the number of top layers. I don't use Cura, so not sure if the setting exists or something comparable.

TomsCables
Posts: 78
Joined: Mon Apr 14, 2014 8:45 am

Re: Top Layer Issues

Post by TomsCables » Thu Sep 27, 2018 2:20 pm

I forgot to mention that.
Nozzle .35mm
layer height 0.2
Walls/top 0.8 (so 4 layers)
infill normally at 40% with using the lines type.

User avatar
piercet
Posts: 3965
Joined: Sun Aug 25, 2013 1:37 am
Location: Battleground, WA
Contact:

Re: Top Layer Issues

Post by piercet » Thu Sep 27, 2018 2:43 pm

Yeah, more top layers and additional shells may be the way to go there. Or if it's a small enough part just keep the high infill. Turning cooling fan on for the last layers (it's basically a bridging operation) would also help.

TomsCables
Posts: 78
Joined: Mon Apr 14, 2014 8:45 am

Re: Top Layer Issues

Post by TomsCables » Fri Sep 28, 2018 11:31 am

So I went back and tried printing an old file that works from a few weeks ago. The only difference in my setup for the one that worked was I was using a Red colored ABS and now I'm using Black.

But it did the same thing with a crappy top surface.
Attachments
key bad surface.jpg

Galadriel
Aleph Objects | LulzBot
Posts: 223
Joined: Mon Sep 25, 2017 10:23 am

Re: Top Layer Issues

Post by Galadriel » Fri Sep 28, 2018 2:23 pm

Filament can have an affect on your overall print quality. Is this an old roll of filament? Filament can absorb moisture overtime becoming much more difficult to print with. I would recommend you try switching back to the red ABS using the new model and see if you are still seeing the new model come out poorly. If not it will almost certainly be something going on with the filament.

TomsCables
Posts: 78
Joined: Mon Apr 14, 2014 8:45 am

Re: Top Layer Issues

Post by TomsCables » Wed Oct 10, 2018 7:34 am

Sorry for the late reply on this.
The Black ABS was a brand new roll just opened from Village Plastics.

I found some other parts that I had printed before switching to the Red ABS with the old roll of Black ABS and they were showing issues with the top surface also. So I guess for some reason my printer doesn't like printing decent top surfaces when using Black ABS unless you run it close to 100% infill.

TomsCables
Posts: 78
Joined: Mon Apr 14, 2014 8:45 am

Re: Top Layer Issues

Post by TomsCables » Wed Oct 10, 2018 12:52 pm

Ok, I think I might have figured this out.
Just for giggles, I ran this file through a really old version on slic3r (1.2.9 for those playing along at home)
It printed just fine with a good top surface. (It had some adhesion issues to the bed but the top surface is 100% better than my other attempts)
Digging through the slicer profile I noticed the Default Extrusion Width was set to 0.25mm, Infill was 0.24mm, and Top solid Infill was 0.25mm (Print settings/ advanced/ Extrusion Width settings)
Checking Cura 3.0 it has all of these settings set to 0.35mm (These are under the Quality setting)

Looking closely at the attached pictures especially the pic of the bottom of the part. It appears that the 0.35 spacing is to much for the printer and is leaving a gap between each extrusion.
I don't know if its common for the Extrusion width to always match the nozzle size? If it is I guess I'm underextruding then?
Attachments
slicer vs cura bottom.jpg
Slic3r (Left) VS Cura (Right)
slicer vs cura top.jpg
Slic3r(Left) Vs Cura (Right)

Post Reply