ok you expect the file for free or you need guidance?
First you need to list the parameters you want to drive, then all other conditions you want. Then you start building geometry. A robust parametric construction would avoid using BREP, so keep that in mind when you create your geometry.
post your file for progress and explain where the problem is so we can help.
Eric N. indocti discant et ament meminisse periti
Dimension/parameters do not count too much....
I am only interested to know if Catia has a feature that extract the centerline of this unparametric solid.
NX has a feature that can do this..................
catia can't do it in one click (for the full solid) and it might actually be faster to read some measurements and build a new curve.
if you want to go the long way: create a point on the planar end face and then create a isoparam curve on the surface along the geometry then a sweep on that isoparam at 90deg to the surface, then length of the sweep should be equal to the radius.
then extract the boundary of the sweep:
Eric N. indocti discant et ament meminisse periti