For the drill press you would want to replace the handle with a timing pulley or sprocket and then connect it to a pulley/sprocket on a stepper motor. Steppers don't have a lot of torque so you want about as big of a sprocket on the drill press as you can fit and then a correspondingly small sprocket on the stepper. Your press needs a limit switch (a lever microswitch) so you can detect when it has been fully lifted/retracted. So long as the stepper is strong enough that you reasonably don't need to worry about losing steps (you'd want a medium length NEMA 23 size) then there should be no need for an encoder.
Instead of a sliding platform to load cans under your drill press what you want to use is a "star wheel". Not really a great example but take a look at: http://www.filtec.co.za/BottleFilling_SemiAutomaticBottleRinsers.aspx. In your case you would want the wheel positioned vertically so the cans would fall into the wheel slots from a chute and correspondingly drop out just as easily. A star wheel like this would again be turned using a stepper motor. To ensure the wheel has rotated to the proper position you should use an indexing hole and photointerrupter or perhaps another lever microswitch that would trip against pegs in the wheel.