The design of a chess set

Kim Tech is working on designing a chess set for Digital Design. He discovered the screw modifier in Blender and used it to make spirals around a test piece. He encountered a few problems, such as that the ends of the spirals were open (he solved that by adding spheres at either end) and the 3D printing program had problems with reading the exported file (he recalculated the normals).

Finally he got a piece that the printer could print, but Ms. Chelsea put a cylinder in the center to prevent the need for supports during the printing process. Now Kim Tech wants to find a way to make the center hollow without needing supports. The printer can only print up to a 45% angle without supports.

Here it is printed! 

I can't wait to see Kim Tech's next design! And maybe have a game of chess with custom designed chess pieces...