This paper involves the systematic, integrated and unified design of an automatic apple grading system. Apples are placed on a constant-speed conveyor system and graded based on 2 parameters: weight and colour. For weight detection, a piezo-resistive load cell (ELAF-T1-M-10L) is used. For colour detection, an RGB colour sensor (46CLR-D5LAC3-D5) is used. If the apples are equal to or above a pre-set weight threshold of 0.08kg and if the colour of the apple is red, green or yellow, they are graded in to three bins (bin 1: red apples, bin 2: green apples, bin 3: yellow apples). If the weight is below the threshold and/or if the colour of the apple is not red, green or yellow, they are sent to a reject bin. Both weight and colour requirements have to be met to be successfully graded, otherwise the apple is re-jected. Electric linear actuators (PA-15), actuated by combined signals from load cell, colour sensor and photoelectric sensors (OBR2000-R2) positioned very close to the actuators, are used to eject the apples to the correct bins. A digital magnetic speed sensor (DIGISPEC 0090/0091) is used to monitor the speed of the motor and maintain the required constant conveyor speed. Food grade conveyor belt (NS20 UFMT) is used to design the conveyor and direct drive DC motor (DMS07G) is used to move the conveyor belt. In this paper, the functionality, operation, important parameters and justifications for choosing individual components have been provided as well as detailed explanations of the overall system operation, along with potential drawbacks of proposed system. Relevant calculations necessary for system design are also provided.