An attachment arm assembly (28) includes an attachment arm (50,51) that is pivotal about an arm pivot axis (54) using a hydraulic lift cylinder. The attachment arm assembly (28) also includes an interface plate (46) pivotal about an interface plate pivot axis (56) and configured to mount a tool (30). The interface plate (46) has a main body (112) and includes a first side edge (102) having a first end (108) and a second end (109). The interface plate (46) includes a second side edge (104) having a first end and a second end (110). The interface plate (46) also includes a top edge (106) that couples the second end (109) of the first side edge (102) to the second end (110) of the second side edge (104). The first ends (108) of the first and second side edge (102,104) are spaced apart from each other a distance greater than a distance between the second ends (109,110) of the first and second side edges (102,104).
