An orbital sander includes a housing, a drive unit within the housing having an electric motor defining a rotational axis, and a drive shaft coupled for co-rotation with the motor about the rotational axis having a fan rotatably coupled to the lower portion of the drive shaft. The fan includes a main body having a plurality of fan blades, an upper counterweight located on one side of the main body and a lower counterweight located on an opposite side of the main body for balancing the operation of the fan, and an interruption region located opposite the lower counterweight with fan blades located within the interruption region having a reduced mass. The orbital sander further includes a baseplate for selectively mounting a sanding sheet that is coupled to the lower portion of the drive shaft for orbital rotation about the rotational axis.