Hi Dave R!

I tried out your tips, and it absolutely works. Thank you very much for your quick answer. I would like to ask another big request. I tried to design lightning protection system with SketchUp. The result, which I would like to reach the so-called protected zone (please the enclosed picture). If I draw a normal building (rectangular floor area for example 40 m length, 20 m width and 20 m height), it's possible that could you write the basic steps (the best if you could show with print screens) how to design the lightning protection system's protection area for the building with Sketchup?

I used Autocad before for this function (design the protection area), but I would like to use this designing at SketchUp as well.

Thank you very much for your helpfulness in advance and I'm waiting your answer.

I tried to roll the sphere around the vertical line, but I couldn't create the inverted funnel as shown at the picture. Could anybody help what are the basic steps to create the same model, which is represented at the picture?

Thank you very much in advance.