CATIA, new user, need help with Sketch for Rib

[Kamsta]

Hey,

I just started using catia as i need to learn it for Formula Student with my uni. I was trying to create an airfoil (part of a rearwing of a car) and for some reason i cant make it into a 3d object by using 'Rib' tool. I'm attaching a screenshot so you can see the error message as well as the sketch.



Also, i dont really understand the purpose of constraining, my friend did it apparently without constraining...

Thanks!

 

[MrCATIA]

I've seen that message many times. It means your sketch is not closed, or it has some extra geometry. (looks like some extra points at the trailing edge) You'll have to fix the sketch before you can use it for the Rib.

If the profile is not closed, you probably need to Trim the open geometry.

If there is extra geometry, you need to Delete it (or make it construction geometry).

While you have the sketch open, the Sketch Analysis tool is very helpful to show you where the sketch is open (little blue circles at the ends of profiles), and where you have extra points. Your professor should be able to show you how to use it.

 

[MrCATIA]

Also, i dont really understand the purpose of constraining, my friend did it apparently without constraining...

Thanks!

Sketch constraints and Assembly constraints are not absolutely required, but they are used to define the exact shape and size of the features within your design. Without constraints, it is too easy to inadvertantly move something and have the wrong dimensions.

I suggest always use constraints when you make/edit a sketch and always fully-constrain all sketches (everything should be green, or yellow).