A wrapping machine for wrapping trayed items, comprising: - a wrap station at which trayed food products are wrapped; - a film dispensing system for drawing out film at the wrap station; - a conveying system for moving trayed food products along a defined path from an input station to the wrap station, wherein the conveying system includes a conveyor for moving trayed food products from the input station to a trayed item detection arrangement and a primer mover operatively connected for moving the conveyor; - a controller operatively connected to the trayed item detection arrangement and the primer mover, the controller configured for carrying out a self-calibration operation, characterized in that the controller is connected to a first sensor arrangement and an encoder for carrying out the self-calibration operation in which - the primer mover is operated to cause movement of a portion of the conveyor from a start position to the trayed item detection arrangement; - an amount of movement of the primer mover is monitored as the portion travels from the start position to the trayed item detection arrangement and the amount of movement is used to determine a distance from the start position to the trayed item detection arrangement; and - the determined distance is stored as a calibration value in memory of the controller for future use during trayed food product wrapping operations. - a wrap station at which trayed food products are wrapped; - a film dispensing system for drawing out film at the wrap station; - a conveying system for moving trayed food products along a defined path from an input station to the wrap station, wherein the conveying system includes a conveyor for moving trayed food products from the input station to a trayed item detection arrangement and a primer mover operatively connected for moving the conveyor; - a controller operatively connected to the trayed item detection arrangement and the primer mover, the controller configured for carrying out a self-calibration operation, characterized in that the controller is connected to a first sensor arrangement and an encoder for carrying out the self-calibration operation in which - the primer mover is operated to cause movement of a portion of the conveyor from a start position to the trayed item detection arrangement; - an amount of movement of the primer mover is monitored as the portion travels from the start position to the trayed item detection arrangement and the amount of movement is used to determine a distance from the start position to the trayed item detection arrangement; and - the determined distance is stored as a calibration value in memory of the controller for future use during trayed food product wrapping operations. - the primer mover is operated to cause movement of a portion of the conveyor from a start position to the trayed item detection arrangement; - an amount of movement of the primer mover is monitored as the portion travels from the start position to the trayed item detection arrangement and the amount of movement is used to determine a distance from the start position to the trayed item detection arrangement; and - the determined distance is stored as a calibration value in memory of the controller for future use during trayed food product wrapping operations.