An operator interface assembly for a machine includes a base, an operator input device, a first biasing member, and a second biasing member. The operator input device is operable to move in a direction in relation to the base. The first biasing member is operable to contact the operator input device at a first position and resist movement of the operator input device in the direction. The second biasing member is operable to contact the operator input device at a second position and resist movement of the operator input device in the direction.