The specification discloses a bottom board feeder apparatus for feeding bottom boards onto the top surface of mold boxes of varying heights. The bottom boards are supplied in succession to the apparatus by a first conveying line. The mold boxes are supplied in succession to a board receiving position adjacent the apparatus by a second conveying line. The apparatus includes a proximity sensor for detecting the height of a mold box in the board receiving position and an elevating mechanism responsive to the sensor for raising a bottom board so that the bottom surface of the board is at least as high as the top surface of the box. The apparatus also includes a shuttle mechanism for pushing the board onto the top surface of the box after the board has been raised. A control system including electrical and hydraulic circuits is provided for automatically controlling the cyclical operation of the apparatus.