Technically, this is what the drawing defines without further information. No method of attachment of the vanes. Also, dimensions b & c are assumed as 30 and 50, although it leaves a non-circular center. Post machined? Are b & c accommodation values to better represent a circular center and circumference?
If the original drawing is a DXF, you should be able to get b & c values, but looking at the drawing, and the vane thickness of the other vanes in the section, I might not trust that either.
