Thanks for your very prompt reply.

It is a bit difficult to explain, exactly, in words what I want.

My idea is to rotate the model on a copy of a section of the shape.

Inside the base I will house a small motor. The 'skirt' (mentioned in my first posting) is to give me a little more space inside ...

Hi Everybody,

I am fairly new to polyhedra but, quite recently, I have made several models in wood of the various basic shapes.

I am including one particular model, that I have just completed, below, to which I wish to add a suitable base ... My problem is adding a sort of skirt (say about 25mm ...