“A friend in Connecticut told me about a CNC machine in his shop that was simple, easy to program and set-up, run and verify tools of all types,” recalled Brendan Slabe, an Ohio machine shop owner.

In an age when you can get just about anything online, it's probably no surprise that you can buy a diamond-making machine for $200,000 on Chinese ecommerce site Alibaba. If you, like me, haven't been ...