### Box lid "finger indentation" - rounded ellipsoidal indentation?

JW
Jim Witte
Thu, Jan 13, 2022 5:36 AM

I'm designing a jewelry box and want to "finger indentation" on the lid/box
seam, and I've got the following sketch of a cube with a subrarted
ellipsoid:

difference() {
color("green")
translate([0,0,3])
cube([20,30,6], center=true);

``````// Pocket ellipsoid
color("purple", 0.7)
translate([0,-15,0])
scale([2, 2, 0.9])
sphere(3, center=true, \$fn=30);
``````

}  // if difference

Except this has sharp edges at the intersection across the front and bottom
faces.  How could I round these off?  (Without importing it into Fusion
which I don't know how to do - but I'm sure it would take about 5 seconds
if I did).

I guessed that I might use minkowski with a small sphere - but that doesn't
seem to work, takes forever, and messes with the geometry outside "just the
pocket".

I thought of making two toruses along the front and bottom edges of the
pocket, but can't figure out what boolean operations to use too combine
them right.  Careful placement of the tori, then union them will the whole
model, then one or more unions with the model?

Jim

I'm designing a jewelry box and want to "finger indentation" on the lid/box seam, and I've got the following sketch of a cube with a subrarted ellipsoid: difference() { color("green") translate([0,0,3]) cube([20,30,6], center=true); // Pocket ellipsoid color("purple", 0.7) translate([0,-15,0]) scale([2, 2, 0.9]) sphere(3, center=true, \$fn=30); } // if difference Except this has sharp edges at the intersection across the front and bottom faces. How could I round these off? (Without importing it into Fusion which I don't know how to do - but I'm sure it would take about 5 seconds if I did). I guessed that I might use minkowski with a small sphere - but that doesn't seem to work, takes forever, and messes with the geometry outside "just the pocket". I thought of making two toruses along the front and bottom edges of the pocket, but can't figure out what boolean operations to use too combine them right. Careful placement of the tori, then union them will the whole model, then one or more unions with the model? Jim