Bug, invalid geometry added

I am drawing a simple item for a patent application. Due to my lack of Rhino skills i had someone create it in blender who then exported it. It came in as a mesh.
I was trying to convert to nurbs using the ToNurbs command and this message popped up.
TBH a bit above my pay grade (In Rhino), but having a go to help my colleague.
Happy to share the file, just not publicly.

Hi JP -

From that image, yes, that does look like a simple item. A simple revolve of a profile?

Why the Blender mesh is bad is impossible to tell from an image but likely also irrelevant.
You can always send sensitive files to tech@mcneel.com but I’d suggest looking into the basics and asking questions here when getting stuck with modeling something like this.
-wim

Hi Wim, Thanks. I’ll upload the file for completeness. I did want to ask someone to assist but then for the sensitivity probably could not. I agree the washer is the easy bit, the rest a bit harder. (for me)
I was just not sure where to start and how to build what i wanted.
I spent some time trying to convert the ‘washer’ into a nurbs and reduce the polygon count but no luck. I can recreate that item, the other part of the drawing not so sure.

The mesh maybe the best way to deal with it. Feed back on that will be helpful.
This drawing is part one of the project.

Hi JP -

From the limited information that was provided, it sounds like you are drawing something mechanical. As such, I have to disagree that doing this with meshes is the best way.

If you have specific questions, we’ll be happy to try to help.
-wim

Thanks Wim. Yes it is mechanical. (I uploaded a file to Tech) I regret paying to have it created in Blender (I misunderstood how blender worked) I will have a go in Rhino and re-create from scratch when i get a gap in other work and ask specifics if needed.