Hi Rudy,

> Why my ring get's divided in two sections?

Your ring is made up of more than one surface - it looks like you created it from a revolve initially and if you go to the profile you used to do the revolve, it's made up of several segments with 2 lines going across it instead of just one big line. You can see that more easily if you select your starting profile and then use Edit > Separate on it, that will break apart the sub segments into individual pieces that you can select.

Here I've used Edit > Separate on that profile curve and selected the different segments so you can see how the curve is structured:



When your profile curves are broken into several different segment pieces like that, then the revolve or other surfaces that are generated from them will be divided into the same kind of structure as well.

So if you wanted to generate a revolve without multiple pieces across you would want to delete those 2 little lines going across the profile and instead have one single large line that goes across, then the revolve would be one piece.

(and actually it looks like you're using Sweep for generating this - I'd recommend Revolve for circular shapes instead of sweep, Revolve will make more exact and also at the same time more lightweight surfaces for circular shapes).

- Michael