OK, I have to admit: at this point of time, I do not have the knowledge yet to design my own 3D things. But it is amazing what other people design and how you can easilly re-use that creativity.
I printed the original clock face for my LED rotating DS1302 clock and I liked it a lot.
Recently I bought this really great clock kit: the VFD rotating clock. It looks great, but there is one problem: I have no suitable case. So I shrunk the Y dimensions and the X dimensions and doubled the Z dimensions and voila: I had a very nice box for my VFD clock!!