GCode Path does not Match Cura path

[BStump 0]

I have two case where when I generate the GCode in Cura 4.9.0 and 4.9.1, the resulting GCode path does not match the Cura path.   Printing on a Modix Big Meter with Duet3D2 WiFi controller (RepRap not Merlin).

 

This bug is pretty concerning as it makes me question the resulting GCode.

 

One example is printing multiple parts one at a time.  I Cura this show's the sequence and nozzle path correctly, one part followed bay another followed by another.  But when I examine the GCode I see the GCODE has it as "All at Once" and has completely ignored the "One at a Time".  I had though it was something to do with more recent addon but now examining a couple jobs I prepped but have not printed it predates those and is present in Cura 4.9.0.  Are there and setting that interfere with the print sequence "One at a Time"?  This one is pretty important as we have some large print batch jobs where we need the Print "One at a Time" functionality.

 

Cura 3MF (Does not match the resulting GCode).  Looks good an the Print Sequence is as desired Two Groups printing sequentially.

 

 

CURA reopening the GCode from the 3MF.  The GCode does not match the Cura tool path image.   The Two groups print "All at once".

 

 

The second case where I see that the GCode and Cura paths do not match is when I ran the Arc Welder add on for a part that has straight sides.  It looks fine in Cura  (3MF) but on examining the GCode I can clearly see that add on is not right for straight sided part or is very buggy.  This oine is of less concern as it is just an Add-On that is not all that Important.

 

Arc Welder Addon Enabled in 3MF in Cura (does not match resulting GCode).  Looks pretty good

 

 

CURA reopening the GCode with the Arc Welder Addon Enabled.  The GCode does not match the Cura tool path image.  I am not thinking the Arc Welder Add on is ready for Prime Time is this was the wrong part for it.

 

 

[Bill_D 0]

I can't comment on the 'one part at a time' issue. But I just experienced the same issue with an "Arcwelded" G-code not showing correctly in the Cura preview. That part is printing as I write this with no problems, so I have to assume that Cura does not recognize G2/G3 commands and just previews them as straight lines.

 

A side effect of that is that now I can see where the G2/G3 commands show up in the layer.

Edited May 26, 2021 by Bill_D

[GregValiant 1,251]

That's correct.  At this time Cura does not interpret G2/G3 commands in the preview.  I think that's being looked at and will be fixed.

 

@BStump is it possible for you to post the 3mf file and the gcode file?  Somebody will take a look.  As far as I know, "One at a time" isn't interfered with by any other setting.

 

 

 

[nallath 1,120]

On 5/26/2021 at 10:33 PM, GregValiant said:

That's correct.  At this time Cura does not interpret G2/G3 commands in the preview.  I think that's being looked at and will be fixed.

It's not really something that has high priority, so don't expect it any time soon.

[BStump 0]

Attached are the 3MF and Code for a One at a time print.  The 3MF shows the print sequence correctly as two groups printed One AT A Time (Sequentially), while the Gcode ignores all that and prints the jobs as All At Once.

ZPTRAY02-01.00.02-10.3mf ZPTRAY02-01.00.02-10.gcode

[gr5 2,172]

I looked at both your 3mf file and your gcode and also sliced your 3mf file.  It works fine.

 

I think what is happening is that you are probably loading the gcode file back into cura and then using the slider and it looks like it prints all at once.  But it doesn't.  Cura has a bug that when it displays gcode files it displays it by layer height instead of the order it is in the file.

 

Am I being clear?

 

It's just a bug in how cura displays a gcode file.

 

I also opened your gcode file in a text editor and if you search for Z0.28 you will find that this occurs twice in the file.  The second time about half way through the file when it goes to print the second part.  So - the gcode is fine.

 

[BStump 0]

On 5/28/2021 at 9:51 PM, gr5 said:

I looked at both your 3mf file and your gcode and also sliced your 3mf file.  It works fine.

 

I think what is happening is that you are probably loading the gcode file back into cura and then using the slider and it looks like it prints all at once.  But it doesn't.  Cura has a bug that when it displays gcode files it displays it by layer height instead of the order it is in the file.

 

Am I being clear?

 

It's just a bug in how cura displays a gcode file.

 

I also opened your gcode file in a text editor and if you search for Z0.28 you will find that this occurs twice in the file.  The second time about half way through the file when it goes to print the second part.  So - the gcode is fine.

 

Thanks.  I did not dig into the Gcode lines to see it was a display vs actual bug.

[GregValiant 1,251]

When printing "One at a Time" each part instance has it's own Layer:0.  When Cura displays a gcode file then all the layer"0's are shown on the bed at the same time.

 

Within the gcode file though, layers might be numbered 0 to 10 and then the next 0 to 10 , and then another group of 0 to 10, etc.  That's the order in which they would print.