To extend the blade, a motor provided in the hilt body is operated to unroll the rolled/spooled plastic blade body members from their reels/spools with each member (or blade half) acting much like a metal carpenter's tape measure. Each blade body member passes through a blade forming guideway or passageway that acts to “zip” the two semi-cylindrical blade body members together (or with portions along their length overlapping each other or one nesting inside the other) as they leave the hilt body, thereby forming the energy blade. To retract the blade, the process is reversed with the motor acting to wind the pair of spools to reel or wind the extended blade body members back into the hilt body and onto the pair of spools/reels.