If the conveyor belt is full the sides will not slide down. You can spray all the water in the world on those sides and they will not slide down until the conveyor belt empties. But before it has a chance they pull another piece of wood. If they would be patient they wouldn't need that much water. It would just slide down on its own but they never give it a chance they're always up there pulling the boards before they should. Then the board gets buried in the steel rod gets stuck. Patience my friends patience.