Forage chopping machines have numerous familiar hazards, such as rotating shafts, gears, chains, and belts. Perhaps the most important thing for forage harvester operators to remember is that their machine is designed to gather in the crop and then chop it into fine pieces so that it can be blown into a trailing wagon. This requires sharp knives operating at high speeds. If your arm or leg is drawn into the machine, then it will be treated exactly as if it were a stock of corn or a swath of hay. Most forage harvesters have a built-in knife sharpener.
Some sharpeners require shields to be removed in order to operate.
Wear eye protection and keep your hands, arms, and head away from the opening. Also, make sure that nothing can fall into the knives. Because the knives are free wheeling and continue to rotate after the power has been shut off, it's tempting to insert sticks and broom handles into the knives to bring them to a quick stop. Not only can your hands be jerked into the knives by this practice, but chips or chunks of wood can be thrown back at you. Always let the knives come to a full stop on their own.