Celtic knots on curved surface

[coproductions]

Hello everyone.
First, I'm not a professional designer/engineer so I am sorry if my wording is incorrect.

I am currently creating a shield piece, that has celtic knots as ornaments. 
The first ornaments were created through projecting my splines onto my surface (shield) and swept around that path.

The problem is, I'd like to give it more dimension by making the path go "over and under" itself, like a real knot would do. The moment i change the points of the path manually, it creates sharp edges.

How do i tackle this task? 

Thank you for the help.

[MichaelT_123]

1. Hi Mr/Mrs CoProduction,

What is the purpose of your Celtic lust?

Is  it about the real creation ... or just CAD design?

Regards

MichaelT

[coproductions]

Well, it hopefully becomes a real creation for a cosplay. I want to print it on a 3D printer.
Here you can see what it should look like.

[MichaelT_123]

Hi Mr/Mrs CoProduction,

I think the task requires manual artistic reconstruction, although F360 can help here.
Look at the attached file. Pay attention to how overpasses are made. I have done two. There are not too many left to finish the shield.
Good luck ... in the battle.

Regards

MichaelT