Hi Anis,

Yeah if Fillet does not produce the kind of rounding that you want at the end, it can be somewhat difficult to model a little smooth cap piece like that.

Sometimes you can do a pretty good one by using Rail revolve with the ending edge as the rail part, but sometimes it can be hard to get a smooth result there. One other way is to do a rounded cap with revolve or rail revolve that does not quite touch the other edge, like this:




That gives you a lot of control over the cap shape by adjusting that profile curve for the revolve. Then you do a Blend here to connect them smoothly:



It can take some fine tuning of the spacing between the parts and tweaking the profile curve's ending direction to avoid having the blend bulge too much in an unwanted direction. History works pretty well for this though, you can set up the revolve (disable the "cap ends" option), and then the blend, history will be all connected up so that you can edit the original profile curve and both the revolve and the blend will update dynamically to see your adjustments.


That's one way to do a custom cap, I wanted to show a technique for that.


But after having said all of that, it is a lot easier to incorporate the rounded ends directly into the initial shaping like Paolo shows above, by using Network or Sweep with some rail curves that model the rounded tip more directly.

Sometimes it can be good to draw one single smooth closed curve and then use Edit/Trim with the "Add trim points" option to split it into 2 pieces to form those rails, that is covered in this blob example:
http://moi3d.com/forum/index.php?webtag=MOI&msg=415.2

- Michael