Cura 14.07: Support structure not in the right places

[peanudt 4]

Hi Guys,

I'm struggling with the support structures in Cura.

This is what I want to achieve:

But this is what I get from Cura.

I tried to change the values for the percentage of overhang, but do not get a proper result. Too low values provide too less support and higher values create a support structure underneath the whole print.

As you can see in picture 2, it is fairly correct, but still in the middle you see parts of the print flying in mid-air.

Any suggestions?

Structure: Grid

Overhang angle: 60

Infill: 10%

Distance X/Y: 0.7

Distance Z: 0.15

All other values are set to normal, but I'm using a 0.5 nozzle currently.

 

[gothampixel 10]

Is this for the Lock-Nesters 3D hubs certification? I'm having the same issue! I was under the impression that these models would be optimized for FDM printing. The default position after loading it into Cura with Support Type = everywhere leaves massive overhangs and parts floating in air.

 

[chrisw 70]

Disclaimer: I'm new to Cura and 3DP in general, just playing with Cura while I'm waiting for my UM2 to arrive.

I'm using Cura 14.09 and it seems like I'm having a similar experience. I have a few overhangs on my item, and supports are being built beneath the overhangs, but they appear to stop about 1 CM below the overhangs. I've changed various settings in the Expert Config, but none of the changes seem to make the supports go where I want them to go.

Any suggestions on a change I should make that I've been overlooking?

 

[peanudt 4]

@Gothampixel: Yes, it is for the Lock-Nesters 3D hubs certification.

 

[gothampixel 10]

@Peanudt

I found that a 54 degree or lower angle for overhang support is needed with this model to provide support for that one leg that is floating off the build plate. Their documentation states their models have built in support but I don't see any. I decided not to continue with the project.

 

[kreativgeek 0]

I'm working on the Lock-Nesters certification as well and I'm rotating every separate piece until the support layers are correct. A bit time consuming but once you have the right angle, it prints ok :-)

Still wondering why Cura is unable to create support in the right places. I guess it is because the first layer is too small to be supported?

 

[peanudt 4]

Hi KreativGeek,

maybe you can share the required rotations for each part :oops: ?

Think it would be a good work-around for 3dhubs to provide these values for the time being.

 

[cyclone 0]

I'm looking at this model as well. It seems they forgot to include the models with supports built in. If you ask the 3dhubs support tech they can provide it to you.

As to why Cura is failing to support this. Looks like Cura only checks the angle of a surface and not whether it has a part of an arc without a leg leading up to it. If you look at the Cura layers you can see that it puts supports only where the angle is 60 degrees, and not where it is <60 degrees but is a totally unsupported feature.

This is definitely a worst case scenario but it is one that Cura should be able to generate supports for. All the other slicers handle this case with no problem.

 

[peanudt 4]

3D Hubs provided the correct file now with the support structures included, so that is solved.

I agree with Cyclone that every unsupported overhang should be included in the build of the support structure. I come across this issue once in a while and it would be great if this could be solved in Cura. I'd rather stick to one software package/slicer and I like Cura :-P