open hollow hemisphere with round extruding circles

Hi

I hope somebody can help me.

I would like to have an open and hollow hemisphere (r=16mm, wall = 1mm). And now the difficult part:

I would like to extrude against outside of the hemisphere 3 rounds and planar circles (about 2mm wall thick, r=14mm). The circles has to be equally distributed and the side must be planar.

I managed to make an hollow hemisphere, but i'm stuck with the 3 circles....

Please can anybode help me?

Thank's a lot

Best wishes from switzerland

Andy

SolidworksSurfacing