3D printer

The utility model discloses a 3D printer. The 3D printer comprises a mounting frame, a printing platform and a 3D printing head, wherein the printing platform is arranged in the mounting frame; the 3D printing head is arranged above the printing platform; an axis-Z motion device which is used for driving the printing platform to move along an axis Z, an axis-X motion device which is used for driving the 3D printing head to move along an axis X and an axis-Y motion device which is used for driving the axis-X motion device to move along the axis Y are arranged on the printing platform. Two transmission forms, namely a lead screw nut and a synchronous belt, are adopted; the transmission of the lead screw nut is high in stability, high in accuracy and small in noises and can bear relatively-big load, and therefore, the lead screw nut is used for transmitting in an axis-Z and axis-Y directions; the synchronous belt is light and cheap and has the advantages of accurate transmission rate, free of slip frequency, stable transmission, small noises, large transmission rate range and high transmission efficiency and capability of obtaining constant speed ratio and absorbing certain vibration; moreover, because of the transmission for the axis-X direction of the 3D printing head, the position accuracy of the printing head can be greatly improved.