Hi

I'm learning maya in college right now and i'm having a problem with a project at the moment.

I basically must use curves ( or nurbs I don't even know anymore ) to buid this completely. I have to build this thing:
https://www.jeremielaflamme.com/cours...ign/index.html
and i'm at the part of Birail 2 , this here:
https://www.jeremielaflamme.com/cours...n/Birail2.html
Also, i'm sorry the tutorial are in french but following the images should be enough to understand my problem I think.

So far, I can do the Birail 2 on 1/4 of my cylinder form however I can't Birail 2 on the second 1/4.
https://imgur.com/L7yB7Og
https://imgur.com/xgR90UL
https://imgur.com/iCA3fTQ

It's basically birailing on the other 3 quarters but not the quarter that I want.
https://imgur.com/p5XtKbW
Please help!!!
I've been learning to use polygons and I actually got very comfortable with it but suddently my teachers told us to forget everything about polygons and learn nurbs instead. I'm about to pull my hair out.