Artefacts (gaps) at layer start

[CRAK 0]

Hi,

 

I need some help to get rid of some gaps at the start points of certain layers.

The issue may be linked to the folowing topic, but after some experimenting with setting (e.g. wall order, z-seam alignment to sharpest corner + smart hiding, I managed to get a good print of the Benchy:

 

 

Unfortunately, the same settings don;t work for the xyz cube (profile attached).

 

I'm using a modded Ender 5 Pro: it now has a 32 bit Creality board and Marlin 2.0.x customised for both BL Touch and (most important perhaps) an E3D Hemera Direct Drive.

The cube was printed with ColorFabb CopperFill filament and a 0.6mm steel nozzle.

The cubes usually come out well in regular PLA (like polyTerra or Fiberlogy), PETG (Fiberlogy) and even NinjaFlex. 

ColorFabb CopperFill E5Pro Hemera DD 06nozzle.curaprofile

[GregValiant 1,330]

I think there are a couple of things going on.

Using Sharpest Corner results in the Z seam moving from the corner (where you see the under-extrusion) to the Y and then back to the edge.

 

Just putting it somewhere specific helps to keep it in a row.  That means all the combing moves will be closer to being the same length so the amount of ooze will be nearer the same.  It will make it easier to troubleshoot.

 

The profile shows the nozzle size is 0.4.  "Retract Before Outer Wall" may be having an effect.  The "Combing Mode" certainly does.  You said you were using a .6 nozzle but the line width is at .4.  You can do that but it can be a built in under-extrusion as it has an effect on the nozzle pressure.

I played with the profile.  Take a close look at all my settings but particularly the wall, infill, and travel settings.

You may end up having to use "Retraction Extra Prime Amount" at .15 or so in order to get the pressure up in the nozzle.

GVCopperFill.curaprofile

[CRAK 0]

Thanks for your fast answer. It's spot-on!

I had been wondering why the wall thickness and line count didn't properly compute.

 

I've just printed a new cube using your profile. It came out perfect! I did change the line width from 0.4 to 0.6mm though, as that directly addresses the probable cause. Extra priming sounds like a "patch" or a "workaround". I'll keep it in mind for future use!

 

I felt a bit stupid when you pointed out the wrong nozzle size (or is it line width - nozzle was set to 0.6mm on the screen), but I'm sure that'll properly store it my memory.

 

Thanks!

 

 

[GregValiant 1,330]

"Extra priming sounds like a "patch" or a "workaround"."

Yes it is.  It's the bigger nozzles that can benefit from it as they tend to ooze more when traveling (especially on large "horseshoe" shaped prints).  They are also less prone to leaving a blob when the extra prime comes in.