I claim the ornamental design for a calf-raise exercise machine, as shown and described.
FIG. 1 is a perspective view of a calf-raise exercise machine, showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left-side elevational view thereof;
FIG. 5 is a right-side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The weight plates shown in broken lines in FIG. 1 are for the purpose of illustrating environmental structure, which form no part of the claimed design. The broken lines showing circular elements on the frame, depict portions of the exercise machine which form no part of the claimed design.