Every time we look at the little short Z axis of our CNC mill, we think about converting a drill press to a mill. In theory, it seems like it ought to be easy, but we never quite get around to it.
They usually consist of a drilling head, chuck or collet, motor, and infeed cylinder or other mechanism. Drilling units and tapping units that are designed for machine tapping can operate with CNC ...
A drill press is safer ... If you were ever afraid you couldn’t duplicate a CNC project, this might be the one to tackle. There are, of course, cheaper and simpler options with fewer capabilities.