A device for grabbing and rotating a roll core, which comprises: a) a hollow shaft, a1) extending along a rotation axis, b) a support for said hollow shaft, b1) said support comprising one or more roller bearings (41, 42), c) an expanding mandrel, c1) extending along said rotation axis, c2) having a first end and a second end, c3) jointly rotating with said hollow shaft, c4) capable to translate relative to said hollow shaft, d) a head, d1) extending along said axis, d2) adjacent to one end of said expanding mandrel, e) a rotary electric motor, f) a regulator for regulating the speed and direction of rotation of said rotary electric motor, g) a control apparatus for manually controlling said speed regulator of said rotary electric motor, h) a support member for said rotary electric motor, i) a mechanical transmission, for converting the rotation of said rotary electric motor into an axial movement of said expanding mandrel, said mechanical transmission comprising a sliding tube, 11) extending through said hollow shaft, i2) able to axially slide relative to said hollow shaft, i3) jointly translating but not jointly rotating with said mandrel, characterized in that said head is jointly translating but not jointly rotating with said expanding mandrel, and in that said control apparatus is mounted to said head. a) a hollow shaft, a1) extending along a rotation axis, a1) extending along a rotation axis, b) a support for said hollow shaft, b1) said support comprising one or more roller bearings (41, 42), b1) said support comprising one or more roller bearings (41, 42), c) an expanding mandrel, c1) extending along said rotation axis, c2) having a first end and a second end, c3) jointly rotating with said hollow shaft, c4) capable to translate relative to said hollow shaft, c1) extending along said rotation axis, c2) having a first end and a second end, c3) jointly rotating with said hollow shaft, c4) capable to translate relative to said hollow shaft, d) a head, d1) extending along said axis, d2) adjacent to one end of said expanding mandrel, d1) extending along said axis, d2) adjacent to one end of said expanding mandrel, e) a rotary electric motor, f) a regulator for regulating the speed and direction of rotation of said rotary electric motor, g) a control apparatus for manually controlling said speed regulator of said rotary electric motor, h) a support member for said rotary electric motor, i) a mechanical transmission, for converting the rotation of said rotary electric motor into an axial movement of said expanding mandrel, said mechanical transmission comprising a sliding tube, 11) extending through said hollow shaft, i2) able to axially slide relative to said hollow shaft, i3) jointly translating but not jointly rotating with said mandrel, characterized in that said head is jointly translating but not jointly rotating with said expanding mandrel, and in that said control apparatus is mounted to said head. 11) extending through said hollow shaft, i2) able to axially slide relative to said hollow shaft, i3) jointly translating but not jointly rotating with said mandrel, said head is jointly translating but not jointly rotating with said expanding mandrel, and in that said control apparatus is mounted to said head.