How to generate internal detents

[guimba]

Hello, I am trying to make some small bumps on the inside diameter of a tube to create a detent feature for a part that slides within. I sketched an ellipse on a plane tangent to the ID, then tried to use Dome and a circular pattern around the tube centerline to duplicate four or more of the bumps, but I keep getting 'The face selected for the dome feature is no longer in the model. Please use the Edit Definition to re-select the face.' Any ideas on how to create these?? Thanks!

 

[CorBlimeyLimey]

Try using a revolve cut (or extrude) to create the feature, and then pattern.

 

[guimba]

Thanks CorBlimeyLimey, what I needed to do was select not only the dome feature but also the thin extruded ellipse feature that I used to make the dome itself. Worked like a charm.