Create a dome 2

SketchUp
1

I am trying to use the follow me tool to create a dome on top of a cylinder.
I have a cylinder and I make a center to edge x-section of the dome on top of it.
I select the top surface of the cylinder, select the follow me tool, click the face of the x-section and it disappears.

what did I miss?

I followed the instructions to create a cone. The only diff is that the face of the cone is curved.

update
turns out there is some requirement for a min height.
my circle is 4.75mm rad and my dome is 2mm
a 2.5mm high dome works so I blew it up x10 then shrunk it.

Now I am trying to create 2 inside faces in the dome so I can make a slot in it.

2

Size! if it is small the tiny faces will get you.
Scale up by 10 and try again.

3

I think I did it the hard way but I just finished the hard part @ 10X

just more mysteries to overcome.