Cura defects in print

[JustSumGuy 0]

Hi, I am trying to work out some defects in a print, there are lines that line up with other parts of the print, but only in prints sliced by CURA 3.41
If I use Slic3r PE with the exact (as close as I can setup) same settings the defects are not present.

I much prefer using CURA due to the user interface, and speed of handling GCODE, ability to upload directly to duet (with add-on) etc etc.

but this defect is showing up a lot, and it seems to be a sliceing error, IF this is a defect in the STL it does not show up in the CURA Solid view or the Slic3r PE views or anywhere in rendering. Only in prints and only with CURA. You can see in the far right of the picture how the offending line correlates to part of the model. I have spent days trying to adjust retraction, jerk, accel, etc etc etc to get rid of it, and nothing has any impact. Tried Slic3r PE once and it was gone....

Is there a way to set CURA to do more accurate sliceing even if it takes longer?

Thanx

P.S. this is the barrel of the Colt Paterson 1836 model on thingiverse.
https://www.thingiverse.com/thing:1582850

 

[gr5 2,172]

Well for one you could print slower and cooler - that usually helps quality a lot - say 25mm/sec and 190C.

 

Those lines are horizontal, right?  Which means they are layer lines?  If so it sure looks like you need to clean the Z screw - sometimes when the Z screw gets dirty and you ask to change the Z by 0.1mm it actually only moves 0.09 for example for a few layers then suddenly it moves 0.2mm.  It all averages out in the end but you get these layer lines.  So normally I'd say clean the Z screw and maybe try thicker layers.  Often 0.1mm layers looks better than 0.05mm layers.

 

Or are you talking about that dark line where the barrel connects to the... um... whatever it's called.  That would be a slicing issue if that's what you mean.

[JustSumGuy 0]

1 hour ago, gr5 said:

Well for one you could print slower and cooler - that usually helps quality a lot - say 25mm/sec and 190C.

 

Those lines are horizontal, right?  Which means they are layer lines?  If so it sure looks like you need to clean the Z screw - sometimes when the Z screw gets dirty and you ask to change the Z by 0.1mm it actually only moves 0.09 for example for a few layers then suddenly it moves 0.2mm.  It all averages out in the end but you get these layer lines.  So normally I'd say clean the Z screw and maybe try thicker layers.  Often 0.1mm layers looks better than 0.05mm layers.

 

Or are you talking about that dark line where the barrel connects to the... um... whatever it's called.  That would be a slicing issue if that's what you mean.

 

Thanx for your reply gr5, the marks are vertical in the print.  I think I can say with certainty that it is not a physical property of the printer.  IF it was, then it would make no sense that I was able to get a perfect print from Slic3r PE while using the same print speed, jerk, accel, temp etc etc etc

 

I have tried printing at 40mms with no change in the defect.  Actually no change at all in the quality of the print by going slow.   I usually print at 80mms with PLA, the print I was able to get that was perfect (with Slic3r PE) was done at 80mms

There was some change in other aspects as I adjusted jerk and acceleration settings, but none in the defect.

 

The layer height I am working with is 0.15 and I am using a .3 nozzle.

[burtoogle 513]

Hello @JustSumGuy, is it possible for you to save the cura project file and attach to this thread? That would be very helpful in tracking down what is causing those marks. Thanks.

[JustSumGuy 0]

10 hours ago, smartavionics said:

Hello @JustSumGuy, is it possible for you to save the cura project file and attach to this thread? That would be very helpful in tracking down what is causing those marks. Thanks.

 

Sure thanx :)

CFDMP_Barrel.curaproject.3mf

[burtoogle 513]

It's the z-seam. I have fiddled with some settings and now it runs along an edge under the barrel so it should not be too visible. You can see the settings I used in this image. Hope this helps.

 

[JustSumGuy 0]

9 minutes ago, smartavionics said:

It's the z-seam. I have fiddled with some settings and now it runs along an edge under the barrel so it should not be too visible. You can see the settings I used in this image. Hope this helps.

 

 

[JustSumGuy 0]

I made several changes in the z-seam tried random etc and the printed part always had the defect in the same location.

There is no visible z-seam on the slic3r made part, anywhere.

[burtoogle 513]

YMMV