The ornamental design for a portable electric naildrillmachine, as shown and described.
FIG. 1 is a top plan view of a portable electric nail drill machine showing my new design;
FIG. 2 is a rear side elevational view thereof;
FIG. 3 is a perspective view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a front side elevational view thereof; and,
FIG. 7 is a left side elevational view thereof.
The broken lines in the figures are for the purposes of illustrating portions of the portable electric nail drill machine, which form no part of the claimed design.