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I am a beginner at freecad and I have created a protective case to carry AA batteries in my backpack.

Unfortunately, after 3D printing I realized some of its corners are alarmingly pointy. I know I can smooth out an edge using a chamfer or a fillet. But that's not the problem. The problem is the corners, not the edges.

AA battery case

The cap is formed by boolean intersecting a "main body" with a revolve

main body revolve

I can put fillets on some edges, but the results seem a little odd, and create some kind of degenerate wings.

intersection after fillet

I was hoping there was some other kind of dress-up available in freecad that I could use to make the corners less menacing.

Mutant Bob
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  • you can also fillet corners. Since even the corner has a interior edge. – joojaa Dec 05 '22 at 22:34
  • Filleting corners is probably an option in other CAD software, but I have yet to figure out how to accomplish it in FreeCAD v0.20.1 – Mutant Bob Dec 12 '22 at 18:51

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I'd resort to another intersection in z-direction. This gives you the freedom to design the end of the slider's fin the way you really want it.

Even if as @joojaa suggested there is a possibility to add a chamfer or fillet to that corner it might not always result in what you want. Consider a fillet on a corner a spherical shape. To fit it into the corner the three adjoining edges have to be tangential to that shape. As one can imagine the sphere will have an intersection with the pyramid formed by the edges. At this curved intersection line there will be new edges formed with varying angles between both surfaces. Then consider a corner with four or more edges. A sphere can only be fitted into it, if there's some symmetry between the edges, otherwise one or more edges can't touch the sphere. Other methods like starting several fillets from a polygon fitted into the pyramid will result in the need for free-form surfaces, nothing a simple dress-up can feature.

Another suggestion is to modify the shape of the slider's fin. Is there a reason for choosing a triangular shape? If you choose a trapezoid profile instead, the fin isn't that prickly from the beginning any you can add fillets more easily.

Ariser
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