Cura retraction continuously increases exponentially during print

[jetlink 0]

Greetings,

 

I'm running the latest version of Cura 4.6.1 on my XYZ da Vinci Jr. 1.0 Pro.  I slice and save to the SD card and then print.  It's been printing fine but today I sliced a print and not long into the print it started making an odd noise.  I went over to the printer and discovered that it was retracting an extreme amount of filament and with each retraction it got longer.  By extreme I mean it was retracting at least 100mm of filament or more and I have it set at 6mm.

 

I re-sliced the part and also a different one and they both did the same thing.  Any idea what could be causing this?  I reverted back to XYZ print and it's working fine, well, as good as XYZ print will work anyway.  Unless someone has an idea, I guess I'm just going to re-install the software.

 

Regards.

[jetlink 0]

Anyone got an idea?

 

[GregValiant 989]

I saw your post when you first put it up but I didn't have a clue (that's actually my normal state) about what's going on.

If you post the Gcode file here I'll take a look and see if there is a pattern.  The retractions and primes should all be 6mm if that is what you had it set for.  Are you using "Retraction extra prime amount"?  

[Cre8ed 0]

Hello there,

I too have just started seeing this happen with my Ender 3 in Cura 4.8. I have 'Enable Retraction' setting on so that it retracts 5mm but have 'Retract at Layer Change' off. At this setting, on only a select few prints, I am seeing the filament being retracted after each layer is complete. The first retraction seems to be the same as yours, about 100mm and then at each consecutive layer change the retraction distance increases to the point where the filament is eventually retracted completely out of the Bowden tube and Extruder. 

 

Have you managed to figure out what the issue is yet?

Thanks

[Cuq 162]

M83 added in in the start G code ?

[Cre8ed 0]

Hey there,

Thanks for responding. There is no M83 added to the start G code, however there is M82.

;Generated with Cura_SteamEngine 4.8.0
M140 S60
M105
M190 S60
M104 S210
M105
M109 S210
M82 ;absolute extrusion mode
; Ender 3 Custom Start G-code
G92 E0 ; Reset Extruder
G28 ; Home all axes
G1 Z2.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed
G1 X0.1 Y20 Z0.3 F5000.0 ; Move to start position
G1 X0.1 Y200.0 Z0.3 F1500.0 E15 ; Draw the first line
G1 X0.4 Y200.0 Z0.3 F5000.0 ; Move to side a little
G1 X0.4 Y20 Z0.3 F1500.0 E30 ; Draw the second line
G92 E0 ; Reset Extruder
G1 Z2.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed
G1 X5 Y20 Z0.3 F5000.0 ; Move over to prevent blob squish
M141 S28
G92 E0
G92 E0
G1 F2700 E-5
;LAYER_COUNT:100
;LAYER:0
M117 Layer 0 of 99 CE3_Filament Bearing Guide (Spacer)
M107
G0 F6000 X95.007 Y164.579 Z0.2
;TYPE:SKIRT
G1 F2700 E0
G1 F1200 X95.834 Y164.136 E0.0312

 

I have read in a separate that sometimes when using a USB or SD card, the slot where you insert the card can become filled with dust and cause an error in how the G code is interpreted. 

I have vacuumed the card reader slot but still have the same results. :(.

[GregValiant 989]

No one has posted a whole problem gcode file or 3mf file yet.  Somebody will need to see the problem in order to have a chance of figuring it out.

[Cre8ed 0]

I've uploaded a gcode file where this problem has most recently happened. I'm super new to coding in general, but as I look through the lines with a guide to explain specific gcode from the Marlin website at hand:), nothing seems to jump out at me.

 

Thanks for any help you can offer.

CE3_original_Filament_Guide_Roller.gcode

[GregValiant 989]

Well don't feel bad about your knowledge of Gcode.  Nothing jumps out because there isn't anything there.  I wrote a little macro and read the Gcode file into MSExcel and pulled all the E values out and took a look.  Here are the numbers...

 

There are 71,543 extrusions.  Disregarding the retractions and primes - every E value is greater than the E value in the previous line.  Cura will purposely reset the extruder when the E number gets close to 4166mm of filament (10,000mm3).  There were no resets back to zero after the first layer started.  The max E is 2863.61797.

 

There are 1254 retractions and 1253 primes (the last retraction in a file doesn't get a prime since the print is finished).  In every case, the retraction was 5mm and the prime was 5mm.

 

So there it isn't.  I'll think on this some since the weather sucks and I'm stuck in the house anyway.  Right now I don't know what to tell you.  The long retractions you are getting aren't in the gcode.  There is no M83 in the file so the extruder is not being set relative positioning.  I guess you could try re-formatting the SD card since they need that once in a while anyway.  The fact that the XYZ files are working would seem to point a finger at Cura but in the case of this gcode file at least, Cura is off the hook.

 

Sorry I couldn't be more helpful.

 

EDIT:  My printer is an Ender 3 Pro.  Close enough.  I had an almost empty roll of filament so I printed the file.  There were no problems.

 

Edited January 4, 2021 by GregValiant

[Cre8ed 0]

Greg,

 

Wow! That is an immense amount of time you put in to help me out. Thank you so much for that. I will have a go at reformatting my SD card (thank God for the internet) and see if that works. I have plans to change the original board to the SKR Mini V2 some time this month, and I wondered if that may have some influence on this issue. 
Anyways, I’ll start with the SD card first and then let you know if it helps. Until then, take care and thank you again for your time and encouragement.