Abstract: This invention relates to injection molding machines and, more particularly, to an injection molding machine having an integrated carriage assembly for injection of a material into a mold. The carriage assembly includes an integral injection cylinder and carriage cylinder housing having an outer injection cylindrical wall and a pair of outer carriage cylindrical walls. An injection cylinder assembly is connected to the outer injection cylindrical wall forming a hydraulic chamber, and a motor is mounted on the carriage assembly to form a combined rotary reciprocating hydraulic cylinder. The outer carriage cylindrical walls receive transport rails to form hydraulic carriage cylinders to move the carriage assembly. The mold material density, temperature, pressure, and flow rate are closely controlled by axially controlling the force applied to the injection screw with the combined rotary reciprocating hydraulic cylinder.