Procedure:Lift the upper part and put a glass sheet on the conveyor rollers.Put a try square onto the glass sheet and lower the upper part until the upper air knife does just not touch the try square.In this position, the try square is pushed to the lower air knife slot and one checks the position of the upper air knife slot.Turn the air knife to the right resp. to the left in order to bring the upper air knife slot into position. Figure 4.Then tighten the fastening nuts.8. Re-install protecting cover of the conveyor rollers.