Step 3: Realizing the Sole
Material: I found a nice chunk of Zebra wood at Macbeath Hardwoods in Berkeley (Macbeath was super helpful and has a huge selection!). I am not sure that I would use Zebra wood again since there seems to be so much sensitivity on machining in a direction which is commensurate with the grain.
Pre-processing: Rather than trying to get the toolpath perfect, I did a quick lofted path with a ½” ball endmill and planned on a lot of finish work. In retrospect, a more subtle approach would have been less work in the long run.
Machining: I trued up the block with a large shell mill so that when I flipped the part, I would be able to find the center again. In total, it was about 5 hours of machining (Zebra wood is incredibly dense – it would have been easier to machine aluminum). Obviously, wood is not great for machine tools, so actively cleaning as you go is a good idea.