A mounting assembly for a hair cutting appliance, the mounting assembly comprising: a base (22, 122, 222) and a head, the head comprising a body and a driving bridge and being configured to receive a cutting unit, wherein the driving bridge is configured to couple to the cutting unit and to reciprocally move relative to the body; a pivoting mechanism disposed between the head and the base (22, 122, 222) and configured to permit pivoting movement of the head relative to the base (22, 122, 222) about a primary axis and a secondary axis; and a driving unit (40, 140, 240) comprising a frame (42, 142, 242) and a driving axle (44, 144), wherein the frame (42, 142, 242) is rotatable relative to the driving axle (44, 144) about an elongate axis of the driving axle (44, 144), and provides a bearing surface (52, 152, 252) for the driving axle (44, 144); wherein the frame (42, 142, 242) comprises a body coupling which is configured to couple to the body of the head to permit pivoting movement of the head relative to the frame (42, 142, 242) about a body pivot axis which is parallel to the primary axis, and wherein the driving unit (40, 140, 240) comprises a base coupling (58, 158, 258) which is configured to couple to the base (22, 122, 222) to permit pivoting movement of the frame (42, 142, 242) relative to the base (22, 122, 222) about a base axis which is parallel to the secondary axis; wherein the driving axle (44, 144) comprises: an eccentric driving pin at a distal end of the driving axle (44, 144), the eccentric driving pin configured to interact with the driving bridge to induce reciprocating movement to the driving bridge relative to the body of the head; and a socket on a proximal end of the axle for engaging with a driving head on a motor axle for rotary transmission. a base (22, 122, 222) and a head, the head comprising a body and a driving bridge and being configured to receive a cutting unit, wherein the driving bridge is configured to couple to the cutting unit and to reciprocally move relative to the body; a pivoting mechanism disposed between the head and the base (22, 122, 222) and configured to permit pivoting movement of the head relative to the base (22, 122, 222) about a primary axis and a secondary axis; and a driving unit (40, 140, 240) comprising a frame (42, 142, 242) and a driving axle (44, 144), wherein the frame (42, 142, 242) is rotatable relative to the driving axle (44, 144) about an elongate axis of the driving axle (44, 144), and provides a bearing surface (52, 152, 252) for the driving axle (44, 144); wherein the frame (42, 142, 242) comprises a body coupling which is configured to couple to the body of the head to permit pivoting movement of the head relative to the frame (42, 142, 242) about a body pivot axis which is parallel to the primary axis, and wherein the driving unit (40, 140, 240) comprises a base coupling (58, 158, 258) which is configured to couple to the base (22, 122, 222) to permit pivoting movement of the frame (42, 142, 242) relative to the base (22, 122, 222) about a base axis which is parallel to the secondary axis; wherein the driving axle (44, 144) comprises: an eccentric driving pin at a distal end of the driving axle (44, 144), the eccentric driving pin configured to interact with the driving bridge to induce reciprocating movement to the driving bridge relative to the body of the head; and a socket on a proximal end of the axle for engaging with a driving head on a motor axle for rotary transmission. an eccentric driving pin at a distal end of the driving axle (44, 144), the eccentric driving pin configured to interact with the driving bridge to induce reciprocating movement to the driving bridge relative to the body of the head; and a socket on a proximal end of the axle for engaging with a driving head on a motor axle for rotary transmission.