While I am using OpenSCad this maybe relates to other modeling/CAD programs?
In OpenScad if I want to make a Tee shaped baseplate for example, I can make two cubes and position them in the form of a Tee, render it, then save as an .STL file or I can subract cubes from each other. When I render them and view as a wireframe, I can see the overlapping parts, but not when viewing surfaces.
Does that carry over to the STL file pre and post slicing? Everything I have made has been fine but wondering if that can lead to potential breaking of the part along the line where the two objects join each other.
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When you load it into Bambu Studio do you see a discontinuity there or extra walls being generated?
Two overlapping polygons will (to varying degrees depending on the graphics software and hardware of the computer) look like a single surface if you don’t have wireframe enabled. But really, they’re two overlapping surfaces. These are called “intersecting polygons” and slicers don’t like them. Depending on a bunch of variables, the slicer may or may not have a problem with this.
I have a friend that built his 3D models this way for years. I kept bitching at him that he should do it right. Eventually, he ran in to a problem he spent a week trying to figure out, before he asked for help and I fixed it in less than a minute.
The more complex your model, the more likely it is that the slicer will choke on the intersections.
You should use the “Constructive Solid Geometry” tools in your CAD software to “union” the two intersecting objects. This removes all the intersecting and internal geometry and you are left with just the external perimeter of the two objects and the slicer will be much happier.
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what is this topc for kindly tell me
i want to know this
You may or may not know but I use Openscad to draw whatever shape and I can toggle between Wireframe and Surface views and in Openscad, as you said, you can see the various shapes in Wireframe view.
In Openscad you save a file in .scad format. But you can also create a .STL file in Openscad and then import the .stl via the import command in Bambu Studio.
My guess is that when I convert the .scad file to .stl file in Openscad, Openscad resolves that issue. But assumptions can and are often very wrong.
So far I have not had problems but the question has been on my mind for a while.
Also, when I do a slice in Bambu Studio I look at the sliced object before I send to the printer.
I asked an earlier question related to where a model creator was signing all his models inside the model at whichever layer provided enough real estate for his @JohnDoe signature to fit.
The slicer will complain about “non-manifold” edges if the geometry isn’t “water tight”. But more often than not, these kinds of geometry errors don’t cause a problem.
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I have gotten one or two of those, but in general non-manifold type flags have not been an issue.
I use both the union and difference functions throughout anything I build in OpenSCad.
I’m building a box right now to house a power supply and separate speed controller for the filament winder I built but it sounds like I’m building things correctly.
I do have issues with this.
If I use the MakerLab keychain tool and create a design, I get non-manifold error and it causes issues in the print if I scale down the object to coin size or similar and have the same design throughout the object (from top to bottom). The seam points all end up on top of each other during printing and seem to cause an add-on effect creating artefacts on top surface of the print.
If I hold the printed objects against the light I can even see ever so small holes going through the object.
If I scale up the same object to coaster size it prints great.
We don’t need to solve my problem, İ just wanted to highlight that there could be issues if objects are scaled down. Depends highly on the design of course.