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yannick.m4
(@yannick-m4)
Eminent Member
how to avoid those scars line on top surface

Hello,

 

Here is my issue :

 

 

I have scars where retraction and unretractation start.

 

I don't know the cause of this issue, does anyone have some idea ?

 

Thanks for support

 

 

Posted : 09/06/2019 8:52 am
yannick.m4
(@yannick-m4)
Eminent Member
Topic starter answered:
RE: how to avoid those scars line on top surface

Here is the high quality picture

Attachment removed
Posted : 09/06/2019 9:06 am
Peter M
(@peter-m)
Noble Member
RE: how to avoid those scars line on top surface

Print on the other side if possible.

Test different temperature, lower i would try.

Extrusion multiplier, lower.

Print slower. the infill speed of 200 is often to fast, lower it to 150, then the normal speed you could also lower a bit. if the high infill speed makesthe surface bad, then your top layer will be bad.

Search on this forum for ironing(only in cura), you find tips on getting top layer better without ironing, and with cura you can smooth the top layer of a flat surface.

Posted : 09/06/2019 3:29 pm
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(@)
Illustrious Member
RE: how to avoid those scars line on top surface

When you use drag and drop to the forum; simply change the Link To: parameter from None to Media File.  That allows folks to zoom in.  Easy, simple and proper use of the forum tools.

Posted : 09/06/2019 5:43 pm
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(@)
Illustrious Member
RE: how to avoid those scars line on top surface

The top surface is being slightly over extruded.   The way Plicer slices a part can be affected by holes in the surface. Slicer will print from one side to the other, then reverses direction to fill in places it can't reach in one pass.  This causes thick spots where direction passes meet. Loose belt tension and loose drive gears can make it worse.

 

Slowing down top layer print speed is the best option (20mm/s); and change the infill angle to 0 as this will minimize diagonals, which tend to show the effect the most.   You can also reduce top layer extrusion width from 0.40 to help with the issue.  It will take some trial and error to optimize.

 

 

There are also "ironing" methods, scripts you run on the gcode that make another pass to smooth the top layer.  I haven't used any of these, and doubt they help much. But some do recommend them. Search the web or the forum. I think Cura or Simplify3D has the ability to create an ironing pass, too.

 

 

This post was modified 2 years ago 2 times by --
Posted : 09/06/2019 5:51 pm
JBinFL liked
JBinFL
(@jbinfl)
Reputable Member
RE: how to avoid those scars line on top surface
Posted by: Tim

The top surface is being slightly over extruded.   The way Plicer slices a part can be affected by holes in the surface. Slicer will print from one side to the other, then reverses direction to fill in places it can't reach in one pass.  This causes thick spots where direction passes meet. Loose belt tension and loose drive gears can make it worse.

 

Slowing down top layer print speed is the best option (20mm/s); and change the infill angle to 0 as this will minimize diagonals, which tend to show the effect the most.   You can also reduce top layer extrusion width from 0.40 to help with the issue.  It will take some trial and error to optimize.

 

 

There are also "ironing" methods, scripts you run on the gcode that make another pass to smooth the top layer.  I haven't used any of these, and doubt they help much. But some do recommend them. Search the web or the forum. I think Cura or Simplify3D has the ability to create an ironing pass, too.

 

 

Tim:

I am replying to your post to save the info for future reference.  😀   I saw it a couple of weeks ago and I had to look around to find it again when I finally did a test print with your suggested settings to iron out the top layer... 

This looks very promising and a good fix to what I have been experiencing on some of my home-made and crudely designed prints made with 3D builder and other Freecad software (am not very experienced in CAD but have made some small organizer box things which suffer from ugly top layers like the OP due to cutouts/holes in the top layer ..) 

I did notice that it did not happen on a lot of the designs I have downloaded and could not figure out why it was happening on my self created prints.  It must be the limits of the software I am using, but this fix seems to have reduced this issue.  So thank you.

Strange women, laying in ponds, distributing swords, is hardly a basis for a system of governance!...
Posted : 20/06/2019 9:56 pm
yannick.m4
(@yannick-m4)
Eminent Member
Topic starter answered:
RE: how to avoid those scars line on top surface

Hello community,

 

I have improve very well my top layers and I have almost reduced all the scares !

Here are my settings by priority :

Fill angle 0 deg (this were a very powerfull change)

Filament diameter : mine was around 1.77 instead of 1.75 so there were overextrusion here

Z live ; I upper my settings which seems to have my first layers too squished and so my top layer wasnt build on a regular plane

Lower temperature by 5 deg

Increase extruder multiplier (yes it seems to be weird but when I manually extruded 100mm, my printer was actually extruding 98mm leaving me with discrepencies in X and Y dimensions...

Posted : 21/06/2019 2:09 am
Robbemar
(@robbemar)
Active Member
RE: how to avoid those scars line on top surface

Hii everyone,

 

Hopefully still someone will reply, because I had the same problem on the top. I have only one question. 

Yannick you said that you changed your fill angle too 0. You can find that "fill angle" in the menu from "infill" right in Prusaslicer???? Or do you use an other option in speed??

 

Greetings,

 

Robbert 

Posted : 17/11/2020 2:41 pm
yannick.m4
(@yannick-m4)
Eminent Member
Topic starter answered:
RE: how to avoid those scars line on top surface

Hi Robbert,

 

Yes infill angle mathers but what will definitely remove those ugly scars is the top solid infill width. You need to be below your nozzle diameter. For example for a 0.4 mom nozzle use 0.25 or 0.3 it will under extrude and get a perfect smooth surface finish, even with ABS filament

Posted : 17/11/2020 2:52 pm
yannick.m4
(@yannick-m4)
Eminent Member
Topic starter answered:
RE: how to avoid those scars line on top surface

Check this out. Perfect finish. Even with 45° angle

This post was modified 1 year ago by yannick.m4
Posted : 17/11/2020 2:55 pm
yannick.m4
(@yannick-m4)
Eminent Member
Topic starter answered:
RE: how to avoid those scars line on top surface

This is white ABS

Posted : 17/11/2020 3:02 pm
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(@)
Illustrious Member
RE: how to avoid those scars line on top surface

Plicer 2.3.0.a has monotonic infill, which addresses the key complaint in this thread.

Posted : 17/11/2020 3:02 pm
yannick.m4
(@yannick-m4)
Eminent Member
Topic starter answered:
RE: how to avoid those scars line on top surface

Good to know but try my tip you won't be disappointed.

Posted : 17/11/2020 3:10 pm
Robbemar
(@robbemar)
Active Member
RE: how to avoid those scars line on top surface

@yannick-m4

Your print looks really great on the picture. Can you help me with the settings maybe? I am just new to everything surrounding 3D printing. So how do I change the settings to be below my nozzle. Also I don't find the top solid infill width as a setting in speed. I found width in Multiple extruder.

Btw I don't know the following question. Sometimes i have a little dot on the top surface of my prints. It looks like the nozzle pushed itself onto the surface. People said I could change this with the Z-hop in the slicing program. So far I don't want to change to much in my settings. Do you have idea how to fix that? 

 

If you could help me that would be great. 

 

Thnx in regards,

 

Robbert

Posted : 17/11/2020 3:57 pm
Robbemar
(@robbemar)
Active Member
RE: how to avoid those scars line on top surface

Wait I think I already found it under advance, but I will wait on your response.

Posted : 17/11/2020 3:59 pm
Robbemar
(@robbemar)
Active Member
RE: how to avoid those scars line on top surface

Hello again,

So I tried your trick and I have to say it looks way better than the prints I already had.

Still the scars are still visible. I print 0.2 mm layers. Is there anything else I can change to get a better layer??? 

Posted : 19/11/2020 1:05 pm
Robbemar
(@robbemar)
Active Member
RE: how to avoid those scars line on top surface

Posted : 19/11/2020 1:06 pm
yannick.m4
(@yannick-m4)
Eminent Member
Topic starter answered:
RE: how to avoid those scars line on top surface

Yet it is under advance under extrusion width => top solid infill.

Please show the bottom surface thre one sticking to the bed. You maybe are over extruding the whole time. You should get perfect separated lines, with no hole neither overlapping line.

Like that

Posted : 19/11/2020 1:18 pm
Robbemar
(@robbemar)
Active Member
RE: how to avoid those scars line on top surface

How do I make sure that I don't over extrude??

Posted : 19/11/2020 1:31 pm
Robbemar
(@robbemar)
Active Member
RE: how to avoid those scars line on top surface

I couldn't change my last reaction. I already found a way to lower the extrusion. Thnx a lot for your quick response. I will keep you updated with the results. 

Posted : 19/11/2020 1:45 pm
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