A system for limiting contact between a dipper and dipper attachments and a boom and machinery desk of a shovel, the system defining dipper to boom relative position in terms of crowd amount or hoist length, the system defining the relative position boom limits in terms of a second order polynomial of crowd amount or hoist length. The system also includes a slow speed region of the crowd amount and the hoist length, where the speed is varied depending on the crowd amount or the hoist length. The system also includes a field-strengthening region, depending on the crowd amount or the hoist length, where the field weakening is removed.