What is the best way to make round end on the bangle (jewellery)?

I wannna make a open bangle, now I paused on how to make the open on the side like pic 2.

this is the bangle i am drawing.
pic 2

bangle .3dm (4.4 MB)
this is the rhion file.

Is there any one can help me figure that out?
Thank you.

use cutting planes
bangle .3dm (1.1 MB)

I want round end :joy:, I wonder if there’s best way to do that .

What about using BlendSrf?

I think this is what I want. BY THE WAY, How do you make the round plane ?

I used ExtractSrf and then scaled it down using gumball.

use BlendSrf between half sphere and existing surfaces

bangle editado.3dm (1.0 MB)

Thank you very much.