peterlanoie

@GregValiant Thank you so much!! Clearly I'd been staring at the computer too long. I didn't notice that the bottom face of this piece was indeed a flipped face. I reversed it, recut the chamfer and it slices correctly. I'm irritated with myself that I didn't catch that. Thank you for the second set of "eyes". Cheers! -Peter

I have this simple tube with a chamfer on it: In Cura... prepare view looks fine. But when I slice it, Cura is adding a full skin in the opening on the first few layers (the model in question is on the right of the next picture). It seems the extra skin is on the layers up to the depth of the chamfer. Interestingly, another similar tube (on the left) also with a chamfer does NOT get the superfluous skin, so I think I can rule out slicer settings. If I use the same model but without the chamfer as seen here: and then slice without changing any slicer settings, it's fine (still the model on the right): For more analysis... here are the 2 samples as seen in Windows 3d viewer. First no chamfer: And WITH the chamfer. The STL doesn't seem to have anything that would suggest the need for the skin. I have looked through all the slicer settings, re-exported the STL from the model, re-added the chamfer, but with no resulting change. I have done several models previously with chamfers with no issue. I also did some test samples of this same tube, but only a short section of it (it was a hollow tube, open on both ends) and Cura did NOT add this extra skin. Since perhaps it's relevant, the top of the tube is closed off, but has a 45 degree inner chamfer so it works without supports. Of note also, the second one that slices without the extra skin in the slice preview images above is basically the same geometry as the problem one with a closed off end. I've run out of ideas. Hoping someone here has seen this problem before.

Thank you for the reply and info. I haven't come up with any ideas on how to do this but will keep hunting. For a "capping" solution, I would imagine in the slicer that you could look at the print locations of a layer and see if they fall on an x/y location that is in between infill lines. Or examine all the spaces between infill lines, and see if there's lines above it on the next layer, then compute a skin fill in those infill spaces. I wonder if (depending on the approach) the process would end up in some kind of weird recursive situation: if you add a skin in infill space, does the process logic then think the layer below it should also have a "cap" support skin? Then you'd end up with 100% infill. :-( Not knowing the details of the slicer algorithm I obviously can't appreciate the complexity of it all.

Background/problem I have been researching this idea but can't find anything that seems to accomplish it. Consider the following: you have a layer skin that reaches beyond the perimeter/wall of a previous layer's wall, but you have infill. However, the next layer's wall pattern includes geometry that can not reliably be printed in open, unsupported space due to turns, etc. Essentially, it's not technically overhang since it's inside a solid model but with infill it becomes overhanging. Simply bridging between infill lines isn't sufficient since the walls aren't perfectly straight lines. Is there a way to "cap" or skin the infill between the infill lines on the layer just prior to the layer that will need the support? I realize that I could easily solve this by doing 100% infill but that's major material waste. "Gradual Infill Steps" is better but still has issues with very shallow angles resulting in still unsupported areas. I've poked around all the Cura settings, but can't find something that does the trick. Here is a visual breakdown of the idea. For simplicity to reduce visual noise, I'm showing only the 2 layers in question, but these would be in the middle of a print. In the case of this example, they are layers 31 and 32. At this point in the model underneath this particular feature, layers 1-30 are just infill. Layer 31: includes the infill lines with open spaces. Layer 31: wall and skin "overhang" the infill's open space. While the skin lines would attach to the wall, at this point the wall is already collapsed in some places. Here's another look but with "x-ray" to see the layer 31 infill lines underneath: There are some sections that would basically be ok since they are fairly straight lines. However, while not extreme, there are sharper turns that would stretch out straight - losing detail - or droop when adhered to the next infill line it contacts - causing more serious degradation if not outright failure of the print. "infill capping" concept idea and outcome Layer 31, but now with infill "caps" (solid yellow would be skin lines): Layer 32, fully supported on top of the caps: And again, layer 32, but "x-rayed": Does such a concept or feature exist in Cura? How challenging would this be to realize in a plugin? Looking forward to the expert's and community's feedback. Peter