A corner unit for a feed conveying system includes a housing and a wheel. The housing defines a cavity and a track. The track is configured to receive a material conveying string. The wheel is disposed at least partially within the cavity of the housing and is configured to rotate within the cavity. The housing includes a plurality of ridges protruding into the cavity. The wheel includes a central hub, an outer rim, and one or more spokes extending from a first end coupled to the central hub to a second end coupled to the outer rim. At least one of the one or more spokes is swept such that, when the wheel is rotated in a first direction, the second end trails the first end such that rotation of the wheel in the first direction sweeps material that enters the cavity from the cavity and into the track.