Why Can't I slice Wheels or Rims face up without getting a plug/disc covering it?

[Sebastian Finke]

Thanks Guys! I was able to fix my sketchup wheel Kris_Wheel and also fix other models with the Microsoft link...

https://modelrepair.azurewebsites.net/

I'll try to start getting familiar with the AutoDesk and other apps. Spent all day in Creo at Work, might as well just add another one to the pile.

Autodesk 123D
Creo Elements
Design Spark Mechanical
FreeCAD

These are the ones people rave about. Haven't tried them myself. I'm sure there are more.