This is a CNC Motion System I've designed and built over the last few months. It's based on the OpenBeam extruded aluminum rails, with OpenBeam rollers (smooth running delrin wheels on bearings). The wheels for the Z axis are polycarbonate, to reduce deflection under load.
All of the plates, brackets, etc were designed by me and cut on my (bigger) CNC router.
Is controlled by a TinyG running Chilipeppr. The tinyg is setup as a web server and the g-code sender is a Chrome app. With a webcam I can watch the CNC's progress, and even hit the E-stop from any internet connected device in the world.
This is still a "work in progress." For now I built a light duty spindle from a r/c brushless motor to carve foam and balsa models. Later I'll build a 3d printer extruder for 3d print experiments, and I also have plans to build a laser cutter head. The goal is to quick connect any of the three, but 3d printers and lasercutters would benefit more from a faster belt driven system.