I took a Shapeoko 4 Pro CNC, which is a belt driven machine, and redesigned it around ballscrews for the X and Y motion. I reverse engineered the stock machine and rebuilt it in CAD, and made the new parts using the existing Shapeoko. It was made out of 6061-T6 aluminum, and some 3D printed components.
I'm also pretty happy with some of the cutting boards I've made: https://www.longtailwoodcraft.com/images/cube-board.jpg