To perform hack machine calf raises, stand in place on a regular hack squat machine pushing your shoulders up against the pads. Depending on which hack squat machine you have available at your gym this exercise may vary a little. Place the point of your toes on the foot pad with the rest of your feet hanging over the edge. Next extend your calves, just as if you were standing on your tip toes until your calves are in a fully stretched upward position. Slowly lower your heel down as you go back down into your starting position. Repeat the process.