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submitted 1 month ago* (last edited 1 month ago) by iuvi@lemmy.ca to c/freecad@lemmy.ml

Hello!

Is there a way in FreeCAD to round off the corners of shapes specifically like this? Without rounding the edges themselves (i.e., the rounded corner tapering off to "zero" at the edges).

Thank you

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[-] in_my_honest_opinion@piefed.social 5 points 1 month ago* (last edited 1 month ago)

Slice the corner, then round the edges of the slice maybe? Or imbed a sphere into that corner where the radius is the desired corner "zero".

[-] vatlark@lemmy.world 4 points 1 month ago

Oh the sphere is a clever solution.

[-] iuvi@lemmy.ca 2 points 1 month ago
[-] vatlark@lemmy.world 3 points 1 month ago* (last edited 1 month ago)

Upon further thought... I'm not sure. Mental geometry is hard.

I was thinking that the radius of curvature would be constant as you rotated around the vertex. It may work:

So you could make a sphere inside your part, but don't merge it with your part, the sphere is just a tool. The radius of the sphere would be the desired radius of your fillet. The sphere would be made tangent to each of the edges that approach the vertex(the corner).

Then you remove everything outside of the sphere. To do that you could sketch a triangle where the points of the triangle land on the three edges. But the plane the triangle sits on needs to be on the vertex of your part and it is parallel to the plane that intersects the three points where the sphere meets the edges. Then extrude your triangle up to the surface of the sphere. But it needs to be a subtractive extrude, so it deletes material from your part.

Maybe I'll try. Its a fun excuse to use freecad more.

[-] SaveTheTuaHawk@lemmy.ca 3 points 1 month ago

make a triangle in the corner, merge it with a sphere using a boolean cut.

[-] iuvi@lemmy.ca 2 points 1 month ago

Looks like proposal by edwilliams16 very close to solution https://forum.freecad.org/viewtopic.php?p=879759#p879759

[-] WbrJr@lemmy.ml 1 points 4 weeks ago

Another idea I just had:

Create a plan that goes through the 3 corners that the 3 edges of the corner you want to change, connect to. Create a offset plane from that plane, until it reaches the depth you want to cut off the corner. Then cut it off and use a fillet to make the corner smooth

[-] iuvi@lemmy.ca 1 points 4 weeks ago* (last edited 4 weeks ago)

ou want to change, connect to. Crea

Good, but see this topic and this post, maybe someone will fix this macros someday. Unfortunately too many things fall on my head :( https://forum.freecad.org/viewtopic.php?p=879759#p879759 + https://forum.freecad.org/viewtopic.php?p=880265#p880265

[-] Rolive@discuss.tchncs.de 1 points 1 month ago

I'm pretty sure that chamfer works. Click the corner and check available tasks there should be an option.

[-] iuvi@lemmy.ca 1 points 1 month ago
[-] Rolive@discuss.tchncs.de 1 points 1 month ago

Huh, indeed it doesn't. It seems like an oversight to me.

There is a workaround by using some kind of boolean operation with a sphere and a cube but this seems excessively difficult to me.

this post was submitted on 24 Mar 2026
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