Odd slicing result, asking for education

[jgmick1 0]

Me:  Old goat, but newbie to 3D printing.  Learning as I go.  Need some coaching on this one to understand better what is going on.

 

Generated a printer file with Cura.  The part has a shallow sloping overhang above the build plate, so Cura generated a grid support for the overhang.  The support seems to me to be very odd.  Very non-symmetrical across the Y axis.  Looks like no support at all for the right (+Y) side of the structure except a single line at the end. Large triangular shaped span area with no support.  Not at all what I expected.  Enclosed is the G code file.

 

As an experiment I generated a simple bent plate with overhang.  Cura sliced that and generated a full width support under the overhang as I would have expected.  Tried a wider version of same and also got full width support.

 

Why the difference with this part? Some setting I missed? (not hard to do, there are many.)  Something in the STL model that I generated?  My viewer and CAD system don't how anything odd. 

 

Some advice and education would be greatly appreciated.  Every day you learn something new.

Deck Cap2.gcode

[gr5 2,267]

1) Look at the part in "prepare" mode.  Note red areas.  Those are considered areas that may need support.

 

2) By any chance did you use sketchup to create your model?  If so, right click on all gray surfaces and select "reverse faces" and try again.  More info here: https://i.materialise.com/blog/3d-printing-with-sketchup/

 

Please supply photos of your part in prepare, xray, and layer view (some of us are too lazy to open a gcode file until we get intrigued).  Also posting the project file is more helpful (in cura do file  save).

[jgmick1 0]

Every now and then things get strange for no reason.  Just happened.

 

FYI, I generated the source in Turbocad and exported the STL.  That has been working fine on several dozen parts.

 

Now for strange.  I just tried to repeat the process to get the images you asked for and got an absolutely normal looking support grid under that overhang.  Whatever happened the first time won't repeat, no idea why.

 

Also FYI, I am actually using Repetier-Host at the top level.  I selected the Cura engine within Repetier for the slicing since I was familiar with it from previously using Cura at top level.  I assumed that slicing problems would be appropriate in this forum not withstanding not using the Cura front end.

 

So for now, the problem is gone by whatever means the computer gods saw fit to do to me.

 

Life goes on ...

[gr5 2,267]

I always save every potential print as a project file (do file save as).  That way you should be able to duplicate any bugs just by opening the project file.