Abstract: A folding door or gate arrangement and method of operation thereof for a mobile cotton harvesting machine including a tiltable cotton module builder. In one embodiment, folding door or gate arrangement includes primary and secondary folding door segment pivotal between a folded or closed position in at least partially closing relation to an open end of the module builder and an unfolded or open position at least substantially parallel to a floor thereof, and a door driver arrangement connected between the primary door segment and the secondary door segment including a pivoting link element that facilitates pivotally moving the secondary door segment while the module builder is pivoted to an unloading position without exerting binding or potentially damaging loads against the door segments or the drivers to provide a straight inclined path for unloading or loading cotton onto of from a surface lower than the module builder.