90 degree overhang not supported?

[latreides 4]

I have a print with a relatively small 90 degree overhang.  I have supports turned on, yet no supports are placed under this overhang.  What settings do I need to adjust to get support under this?  Other slicers (Like S3D and Slic3r) place supports here, but Cura does not.  I have tried multiple printer profiles including the built in UM3 profile, and it does not generate support in this area.

 

When I enable tree supports, it _does_ try and place some tiny half hearted supports here on the very outside edge, but that does not really support the rest of the overhang (and bridging here is not pretty)

Edited June 10, 2019 by latreides

[burtoogle 513]

Hello @latreides, could you please save the project file (.3mf) and attach to this thread. Thanks.

[gr5 2,172]

Check these two parameters:

support X/Y Distance (defaults to .7mm I think)

minimum Support X/Y Distance (defaults to 0.2mm I think)

 

Also look at the part in "prepare" mode (at the top of the screen) and rotate the part to look under that overhang.  Is it red?  If not then the "normals" in the STL file are backwards.  "normals" in the STL file tell cura which is the outside and inside of the part and are used to figure out where to put support but not relied on so much during the slicing step when things are 2 dimensional.

 

What CAD software did you use to create this?  If sketchup then it's trivial to swap the normals on this overhang.  Right click and choose "reverse faces".

 

[latreides 4]

37 minutes ago, gr5 said:

Check these two parameters:

support X/Y Distance (defaults to .7mm I think)

minimum Support X/Y Distance (defaults to 0.2mm I think)

 

I did check them, I tried various settings (including 0.0 for each of them) with no apparent effect.

 

37 minutes ago, gr5 said:

Also look at the part in "prepare" mode (at the top of the screen) and rotate the part to look under that overhang.  Is it red?  If not then the "normals" in the STL file are backwards.  "normals" in the STL file tell cura which is the outside and inside of the part and are used to figure out where to put support but not relied on so much during the slicing step when things are 2 dimensional.

 

The underneath side is red, it definitely thinks there is overhang here.  I would have taken more images but I have no idea how to move the viewport in Cura with a touchpad (only rotate and zoom).

 

37 minutes ago, gr5 said:

What CAD software did you use to create this?  If sketchup then it's trivial to swap the normals on this overhang.  Right click and choose "reverse faces".

 

This was created in Blender, but the normals as far as I can tell are correct (it should be manifold); and both S3D and Slic3r place supports under the overhang.

 

8 hours ago, burtoogle said:

Hello @latreides, could you please save the project file (.3mf) and attach to this thread. Thanks.

 

Its not my model to post, but I should be able to cut off the part thats having issues and post a project file with that later this evening.

[johnse 31]

I had a similar issue were I had a small feature that included a small (0.5mm) overhang on top of an outward 60 degree slope and I could not afford any drooping. The slope was fine without support, but Cura didn’t want to put support under the overhang.

 

I modeled support directly into the model and had it be a solid block of support material. I made the footprint of the support 4mm (.5 under the overhang 3.5 beyond it to give integrity—using breakaway that often doesn’t do well with small fearure. I output them as two STL files and then used merge in Cura to align them. Important note: the stl origins must align to merge properly.

[latreides 4]

7 minutes ago, johnse said:

I modeled support directly into the model and had it be a solid block of support material.

 

While that is definitely a solution (and I have done so in the past with Meshmixer before Cura added tree supports(, the fact that other slicers are able to provide support under the overhang leads me to believe that this is a bug (or configuration) issue in Cura and it would be great to solve this at the software level rather than modify the model.

[latreides 4]

I have attached a minimal sample of the overhang issue.  I sliced off the back section of the model (it should still be manifold).

 

 

Overhang.3mf

[XYZDesignPro 70]

Is this more like what you expect to get?  I opened your 3MF as a model, not as a project so I could apply my "Small Part with Support" profile to it.

 

Try my 3mfOverhang_XYZPro.3mf

My nozzle size is .6 (3DSolex) but no matter.  Just change the line width back to .35 for your .4 nozzle.  All of my settings should be included if you open it as a Project, not as a model.  I have no idea which setting is the solution, but I have customized a lot of them.

 

Let me know if this solves your problem.  Hope this helps . . .

[latreides 4]

1 hour ago, XYZDesignPro said:

Is this more like what you expect to get?

 

Absolutely!

 

I will play with your project and see if I can figure out which setting(s) fix the issue.  Thanks.

Edited June 12, 2019 by latreides

[camroth16 0]

I had a similar problem and this is how I fixed it within the settings...

 

Support Placement:  Everywhere

Support Overhang Angle:  0