Am sure your Ball Mill is considered the finest possible grinding mill available. As such you will find it is designed and constructed according to heavy duty specifiions. It is designed along sound engineering principles with quality workmanship and materials used in the construction of the component parts.
Next, apply a different type of successive milling operation (pocket clearing, parallel, 2D contour, etc.) to clear the excess material. For each of these operations, the proper tool (bull nose mill, ball end mill, chamfer mill, etc. — learn more here) needs to be selected.