A wire preparation device includes a motor, a device housing coupled to the motor, and a wire spinner held by the device housing. The wire spinner is mechanically connected to the motor via power coupling components. The wire spinner extends to a wire end that protrudes from the device housing. The wire spinner includes a collet sleeve defining a channel configured to receive an end of one or more wires of a cable therein through an opening at the wire end. The wire spinner further includes an outer collar surrounding the collet sleeve and selectively movable relative to the collet sleeve to force the collet sleeve to contract radially inward for releasably securing the one or more wires within the channel. The wire spinner is rotated by the motor relative to the device housing to untwist or straighten the one or more wires secured within the collet sleeve.