Cura 4.6.1 Not generating retractions at all?

[dnburrow 1]

Hi all,

 

I've been banging my head against something, and I'm beginning to wonder if I'm going crazy. I cannot get Cura to generate gcode that includes retractions.

 

By way of background, I've been having significant problems with stringing for quite some time, I think since about the time I updated to 4.6 or 4.6.1. I made some changes to my printer (a Creality Ender 3 Pro) at that time, including changing to an all-metal hot-end and changing to a 0.6mm nozzle, which could both easily be causing worse stringing, so I have just been trying to tune with those, and having really, really inconsistent results. In the process of trying to see if I could modify the Change At Z post-processing script to add retraction distance and speed to make tuning a little easier, I started examining the gcode files Cura was generating to see how it was handling retractions (if it was using firmware retraction with G10/G11/M207 or if it was just using G1 with a negative E parameter) and I couldn't find any G10/G11/M207s, and I could only find a single negative E movement in ANY of my recent gcode files, and that one is generated by the starting Gcode for the printer.

 

I've tried searching for E-{retraction distance} in the Gcode files, and I've tried just searching for the retraction distance itself. I've tried setting the retraction distance to a very odd number (like 3.1415) that was unlikely to show up so I didn't get lost in finding other numbers, and it just doesn't show up more than the one time.

 

I've tried doing this with stringing tests that are just two towers. I've tried blowing up the towers to 500% of their original size to ensure that I wasn't running afoul of the retraction minimum travel amounts. I've uninstalled Cura and reinstalled it, leaving all settings at defaults and using a completely default Ender 3 Pro machine profile to ensure it wasn't something that I was changing. I've sliced multiple different models.

 

I cannot get Cura to generate gcode that includes retractions. Is anyone else experiencing this? I don't want to file a bug if it's something I'm doing, but if it's something I'm doing, I'm absolutely flummoxed as to what it might be.

 

I have attached a sample gcode files (Normal Size and 400%), along with the curaprofile (just Standard Quality, but I copied and exported it), the saved project file, and the STL. The only retraction I can find in either gcode file is on line 32 in both cases.

 

Can anyone else help me figure out what might be going on?

CE3PRO_Stringing_Test-Normal-Size.gcode CE3PRO_Stringing_Test.3mf CE3PRO_Stringing_Test-400-percent.gcode StandardQuality.curaprofile Stringing_Test.stl

[dnburrow 1]

Nevermind: Moderator - I figured it out, and you can feel free to remove my post, I can't figure out how. I realized my extruder is in absolute mode, so I don't have movements that are negative, they just go to lower positive values, and I do find places where that occurs.

Edited July 5, 2020 by dnburrow

[gr5 2,167]

If you don't mind we'll leave this up in case anyone else has the exact same question.

 

Note that in cura, in PREVIEW mode make sure moves are visible (checkbox) in "color scheme: line type"and there are 2 shades of blue.  Blue moves are non-extruding moves.  One shade is for retraction moves.  That's a really good way to tell which are which very quickly.  The rules for if a retraction happens is complicated so it's good that Cura shows you which are which.

[Torgeir 242]

Hi there,

 

We've all been there at sometimes, -so this is great inspiration and information to go on!

 

Way to go.

 

Good decision.

 

Thanks

Torgeir

[dnburrow 1]

I don't mind at all, just didn't want to clutter things up unnecessarily. If you think it's helpful for it to be here, please leave it up. Thank you, too, for the additional help!