Vegetation cutting apparatuses may include a wheeled apparatus frame. A cutting assembly may be carried by the wheeled apparatus frame. The cutting assembly may include an elongated chain support member having a chain support member edge. A cutting chain may be configured to traverse the chain support member edge of the chain support member. An engine may drivingly engage the cutting chain.

A system for monitoring an extractor fan of an agricultural harvester includes an extractor fan having a shaft configured to be coupled to a rotational drive source for rotationally driving the shaft, a fan hub coupled to a lower shaft end of the shaft such that rotation of the shaft rotationally drives the fan hub about a fan hub axis, with the fan hub extending between an upstream side and a downstream side along the fan hub axis, and fan blades coupled to and extending radially outwardly from the fan hub. The system further includes a sensor that generates data indicative of acceleration of the extractor fan. Additionally, the system includes a computing system that determines an acceleration of the extractor fan based at least in part on the data, and determines whether the extractor is imbalanced based at least in part on the acceleration of the extractor fan.

A cutting apparatus for a header of an agricultural harvester includes a first wheel and a second wheel. A drive source is configured to selectively drive the first wheel in a clockwise direction or an anticlockwise direction. A knife carrier, including a loop having a running side and a knife-carrying side, is tensioned around the first and second wheels for transmitting torque from the drive source to rotate the wheels and the knife carrier. A plurality of knives cut crop mounted to the knife-carrying surface of the knife carrier. A sensor monitors operation of the knives.