$fn=180; difference(){ rotate_extrude(angle=3)translate([200,0,0])square([24,24]); for(a=[0,90])rotate(a) translate([-300,0,-1])cube([600,600,26]); translate([0,0,3])rotate_extrude(angle=3)translate([203,0,0])square([18,18]); }

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only one radius.

So I just rotate extrude a square ? and than make it hollow ?

Thanks I will try.]]>

This one is composed of 3 sections with [angle,radius] pairs [20,200],[-25,450],[-180,150].

If you only have one section with a constant radius, you can just with a difference of two rotate_extrude(...)square(...).

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What remains is a hollow square beam with a bend according the outer perimeter of the ball.

Now scale up the result to the dimensions of 6 lipo 18650 cells stacked upon each other along their long sides and put it in the box.

Does this help ?]]>

So that will be a beam shaped object. (subtract a cube from a cube will do the math)

However, the remaining box must be slightly curved to follow the shape of the drone landing gear, to which the boxes will be fixed.

Any help in bending a beam , of the resulting box ?

Thomas]]>