Cura 3.0.3 did not generate supports

[Danal 0]

Very interesting situation.  Using Cura 3.0.3, following my normal "workflow sequence" that has functioned correctly prior to this incident. Dragged and dropped an STL on the stage, did some manipulation, etc.  Operating in the "Recommended" dialog (not "Custom").  Clicked the "Generate Supports" box.  Let it slice.  Saved the file.  Printed it.

No supports.  Wasted several hours...

I would assume I forgot to check the supports box, or did something else wrong, except, if you "import" the Gcode file into the profile manager, Cura shows the correct selections to generate supports.  However, there are no supports in the Gcode.

Same thing phrased another way for clarity:  The comments at the end of the Gcode show "Generate Supports" ON.  There are no supports in the actual Gcode itself.  Look in layer mode; they are not there.

Incorrect Gcode file, and a later generated good file, are available.  I don't immediately see how to attach files in this forum; perhaps I am too new.

Thanks,

Danal

Edited October 22, 2017 by Guest

[DidierKlein 729]

Hi and welcome,

You can check the layer view to see if the supports are generated as intended, it's a good practice to always check the layer view before actually printing to avoid obvious problems

Regarding your issue, it's a bit complicated to help, i would assume that maybe the support angle was not correct? In normal view the places where support are needed are identified in red.

To upload pictures, you can go on your name (top right) and select albums, there you can upload pictures, then in a forum post you can add pictures from your albums by clicking on the image gallery icon in the editor

Edited October 23, 2017 by Guest

[Danal 0]

Agreed that checking for supports, and other features, in layer view, is best practice.   At the same time, "trusting" the software to turn on/off a basic feature, that is something that should NOT need end-user verification.

Regarding the possibility of changes of angle: The angles did not change. The sequence was literally:  Open an STL, check the 'supports' box, get Gcode that says it has supports (says so in the ;SETTINGS_3 comments) but does not.  EXACT same STL, a day later, check the box, and supports are generated.  No changes to angles in the STL, no changes to the configuration in Cura.

Absolute proof it is not the angles:

A "diff" of the Gcode files shows the moves generated to print the part are identical (other than the absolute extruder values).  Of course, there are a bunch of extra moves in the file with supports.  

First, remove E extruder moves from both files because they will always be different, being absolute.
>sed -n "s/E[[:digit:]].*//;p"  < "AKL_Table Corners to hold  Reflow Oven - Front v2 - Supports.gcode" > tmp1.txt
>sed -n "s/E[[:digit:]].*//;p"  <"AKL_Table Corners to hold Reflow Oven - Front v2.gcode" > tmp2.txt

Then, get line counts of each file, and of matching lines
>wc -l tmp1.txt
111152 tmp1.txt
>wc -l tmp2.txt
97110 tmp2.txt

Then, get line count of matching lines
>awk "NR==FNR{a[$1]++;next} a[$1]" tmp1.txt tmp2.txt | wc -l
96899

As you can see, of the 97,110 lines of Gcode in the file that was supposed to have supports, 96,899 of them are identical to the file that actually does have the supports.  These are the moves that make the object itself.

This is easily verified by extracting just those lines:

awk "NR==FNR{a[$1]++;next} a[$1]" tmp1.txt tmp2.txt > tmp3.gcode

and loading them in Cura itself.  The objects appear.

Summary:  Cura recorded in the ;Setting_3 lines in a Gcode file that it generated supports; however, it did not. Re-Running with identical settings and STL generated supports.  "Identical" can be verified with utilities, such as 'diff'.

Danal

P.S.  

Verification the settings are identical:
>grep SETTINGS_3 "AKL_Table Corners to hold Reflow Oven - Front v2 - Supports.gcode" > cfg1.txt
>grep SETTINGS_3 "AKL_Table Corners to hold Reflow Oven - Front v2.gcode" > cfg2.txt
>diff -s cfg1.txt cfg1.txt
Files cfg1.txt and cfg1.txt are identical

Edited October 23, 2017 by Guest