This. Drill presses cannot withstand the lateral forces that occur in milling and your chuck can fall out because of the taper on the arbor being only a friction fit. A milling machine has an arbor that locks at the top with a nut or other fastening system to keep it from falling out. The taper of the drill press arbor will loosen and cause chatter, wobble and completely fuck up your accuracy of cutting not to mention it lacks the torque needed for milling and is generally too slow to work properly.