A powered stump grinder at the center front of a walk-behind machine is disclosed. The grinder machine has a front cutter head assembly pivotally connected to the walk-behind machine by a central pivot assembly. The central pivot assembly is securely, pivotally connected to the center front part of the frame or body of the machine, for example, by temporary securement to the frame or body via a conveniently removable mounting plate system. The central pivot assembly includes a vertical pivot axle/axis, for lateral movement of the connected front cutter head assembly. Generally horizontal hydraulic cylinders, extending between the mounting plate and left and right lateral portions of the pivot assembly, serve to control lateral movement of the connected front cutter head assembly by pivoting the pivot assembly, which in turn pivots the connected cutter arm, and hence, the cutter head assembly. A more vertical hydraulic cylinder on the central pivot assembly has a ram which is connected to and controls vertical movement of the cutter arm, and hence the front cutter head assembly.
