'Roof' skin in bridge mode. How to?

[Serg2019 0]

Hi! I'm new in Cura. I'm trying to make "roof" layers over low density infill structures printing as bridges. It seems, it only works for Bridge Skin Support Threshold=100%. Any lesser values cause ordinary skin printing behaviour of the layers (flow, speed etc). How to achieve that bridge-mode printing depending on the given threshold of the underlaying infill density? 

[gr5 2,173]

It works fine for me.  What infill density are you using? 

 

Also why not just leave it at 100% - since typically there is only one infill density for the whole part - does this mean you are using the gradual infill feature?

[gr5 2,173]

@burtoogle - What does the threshold refer to exactly?  If I set infill density to 50% and threshold to 40% doesn't that mean the feature is used 100% of the time on skin over infill?

 

[Serg2019 0]

5 hours ago, gr5 said:

It works fine for me.  What infill density are you using? 

 

Also why not just leave it at 100% - since typically there is only one infill density for the whole part - does this mean you are using the gradual infill feature?

In that example I used zero infill, but I've experimented with different density values - got the same result.

 

100% threshold in not ok as well because it causes another issue... hmmm... For that particuar cube, if I use 3 bottom skin layers then set bridging support threshold = 100% it happens that first 2 layers appear normal but the 3d one becomes bridge-styled. It seems like Cura detects that the 1st layer is like 100% solid but the 2d one is not. So, it draws 3d layer as a bridge over that.

 

I'm not sure if I described that issue correctly. There are too many things at this point look odd for me. For instance, when I change the threshold from 99% to 100%, Cura switches cube walls' speed aswell. I don't know, whether all these issues are bugs or I do not understand Cura's principles right so I do everything odd.

[yellowshark 153]

Maybe it is back to basics, If you are printing top layers over infill why do you want to use bridging when it is not bridging. I do not have the latest Cura and do not know what bridge mode is, lol so probably should not be commenting!

[yellowshark 153]

If you are printing layers over low density infill it just means you need more top layers to get a decent surface, say 1.0mm thickness plus.

[dunni88 1]

I'm having the problem too.  I have a hollow part that has bottom layers and top layers.  0% infill works fine for the whole thing due to the shape.  However, the top does have about a 1 inch opening that I want to bridge.  When I enable bridge settings it doesn't see the top as a bridge because there is material underneath it.  It doesn't matter that the material is not doing anything to support it.  I think this is just a problem with how this threshold works.  The only way for it to see the top as a bridge is to set the "bridge skin support threshold" to 100%.  But then it sees the bottom layers as a bridge as well and applies the same settings to it.