Standing Calf Raises
Seated Calf Raises
Leg Press Calf Press
ALso, there are other calf machines that can be effective
However, the machines and exercises won't necessarily build your calf muscles. It will be your commitment to them to prioritize them and give 100% intensity EACH time you train them. Unless you are genetically gifted with good calves, it will be one of the hardest bodyparts to make grow. But consistency and intensity have brought mine up from my genetically ungifted (is that a word?) bread-stick-calves to somewhat decent ones with pretty good lines.
Also, try doing different rep ranges. One day go heavier (6-8 reps) and another day go 15-20 reps. Good luck!