Here are a few interesting CNC projects starting from small ones, like RasPi case, to big and complex ones, like a full DIY staircase.
Adafruit RasPi case:
Project page:
https://learn.adafruit.com/wood-case-for-raspberry-pi-3/overview
MakeSomething DIY Epipfone guitar body:
HomeMadeModern full wood cofee table made on a big industrial multiaxis CNC:
... and a full size DIY spiral staricase made from stacked CNC cut plywood sheets: