As we'll see, there are a few ways to repurpose an old CD or DVD rack ... usually made of plastic, that gave each CD case a slot of its own to easily slide into. Or not so easily, as was sometimes ...

Aptly called the “CDCNC” thanks to its reliance on cast-off CD drive mechanisms for its running gear, [Paul McClay]’s creation is a great case study ... mills mount the spindle vertically ...