Cura 5.1.1 retracts twice between layers

[TheBigGuts 0]

Hey all!

 

When I enable "Retract at Layer Change"  in Cura 5.1.1 it inserts two retract/prime cycles instead of one.  See GCode snippet.  I added comments where I see the retracts are happening (retract distance is 10mm in this example).

 

G1 F900 X118.728 Y118.859 E169.1823 ;End of last layer
G0 F9000 X118.2 Y118.2
G1 F1800 E159.1823 ;Retract
;MESH:NONMESH
G0 F300 X118.2 Y118.2 Z1.32
G0 F9000 X100.67 Y100.67
G1 F1800 E169.1823 ;Prime for next layer
G0 F9000 X100.3 Y100.3
;TIME_ELAPSED:212.997283
;LAYER:4
G1 F1800 E159.1823 ;Retract again
;TYPE:WALL-OUTER
;MESH:xyzCalibration_cube.stl
G1 F1800 E169.1823 ;Prime for next layer again

 

I thought it may be an overlap with "Retract Before Outer Wall" but I have that turned off and I still get two retract cycles.

 

For kicks, I tried the same settings on Cura 4.8.0 and there is just one retract cycle.

 

Am I missing something and this is intended behavior in Cura 5.1.1?  Possibly a bug?

 

Thanks for your help!

[GregValiant 1,251]

I can't duplicate that so it may have something to do with the way you have Cura set up and your combination of settings.

 

Use the File | Save Project command and post the 3mf file here.  Someone will take a look.

[TheBigGuts 0]

Thanks for the reply!

 

Here is a project file of a calibration that shows the same double retraction behavior (exact numbers different than my above code snippet).  Any comments welcome!

Double retraction question.3mf

[GregValiant 1,251]

I think what's happening is that Cura is adding a regular retraction and prime around the combing moves (;MESH:NONMESH) according to the settings "Retraction Minimum Travel", "Combing Mode", and "Max Comb Distance with No Retract" and then it is explicitly adding a retraction when the layer changes.

 

So it appears that there is no check to see if there was a retraction that was based on other settings, it's simply adding the "Retract at Layer Change" regardless of what else might be going on.  Turning of "Combing" eliminates one of the retractions and leaves the "Retract at Layer Change".

 

Now the question is "Is this a bug?".  I don't think so as it appears to be working the way it was designed.

But that raises the question "Is this annoying?".  I could see where it could be annoying as blobs may be involved.

 

You could write up a bug report over on GitHub.  I did a quick search and didn't see any other mentions of this behavior.  I'm often the greeter over there and it would get past me but at some point it might be changed to a feature request.

 

(BTW I get the behavior you describe in 4.8 in 4.10 as well.  4.13 seems to be like the 5.x behavior.  I will assume that a change was made for 4.11 or 4.12.)

 

Edited October 16, 2022 by GregValiant

[TheBigGuts 0]

Thanks for the reply!

 

Lots of interactions going on when you start enabling these extra options.

 

Your first reply gave me an idea to start from scratch with a default profile.  I had been going down a rabbit hole trying to optimize retraction and coasting on a 0.6mm nozzle.  Once I refreshed the profile and changed just the few settings needed, the double retraction stopped and my print quality issues went away.

 

Thanks for your help on this!

 

 

[JFBP1903 0]

Hey @TheBigGuts, it would be very helpfull with you'd share your latest changes to avoid the double retraction! I've been digging into this issue!

Regards!