The actual cutting of the parts on the CNC is only a small part of the equation, but a lot of people expect it to be the answer! There is a lot of work properly preparing the blanks, setting up the jigs for perfect two sided cuts, dialing in the perfect joint fits, getting cut strategies correct to avoid tearout, etc. Then the real work comes in assembly and final sanding. I'd say I spend three hours off the CNC for every hour spent on the CNC for these stools, even though the parts are completely cut and shaped on the CNC. In furniture building, a CNC basically replaces jigs on a shaper and the additional shaping by rasps and spokeshaves, etc.