There are various CAD challenges out there that come with bragging rights. Some, like the Certified Solid Works Professional Exam (CWSP) might actually look good on a resume. [Deltahedra] is ...

Some objects provide named attachable parts that you can select instead of using the main geometry for the object. One important kind of attachable part is the inside of a tube. The anchors are all on ...

In the example above, the cylinder's center point is attached to the sphere, pointing "up" from the perspective of the sphere's surface. For a sphere, a surface normal is defined everywhere that ...