Maybe you should try commodity trading in the futures market.
It takes a little bit to get started but with patience, you can make a nice profit there.
However, making money for me, is not the objective, but rather the means to buy the tools that I want, in order to do what I want. I know lots of well-off people that really have no purpose for their hoard of money. Pity, really.
In the cnc field, real mass production is really cheap. I don't think the small guy can compete. Smaller lots that will not attract the interest of the big players, or very complex parts that take a lot of know-how and time to do correctly, are better niches to pursue, IMHO.