In a large housing made of grey cast iron, five bores with different diameters from 200 to 600 mm are to be machined. The cored bores have a radial stock removal of 15 to 20 mm and are 120 mm deep. Double edge spindle tools have been used for this machining task up to now.
Due to the high stock removal, two or three spindle tool pre-machining operations are necessary. To be able to machine different diameters, either different tools are required or the tools must adjusted, a time-consuming task. These tools are difficult to handle due to their weight and due to the mostly modular construction. The handling effort is to be avoided and the long machining time is to be reduced using a new machining solution.
The MAPAL solution is a helix milling cutter that is equipped with tangential indexable inserts with four cutting edges. Due to the arrangement of the inserts and the positive, soft cut of the MAPAL tangential technology, it is possible to pre-machine these bores in one step. An optimised cut distribution ensures the wear is specifically distributed between the various inserts and as a result minimised. The helix milling cutter selected for this part has a diameter of 140 mm and is able to machine all five bores one after the other. The number of pre-machining tools required is therefore reduced from ten to just one tool.
The usage of the versatile helix milling cutter significantly reduces the investment in tools. However, the special saving effect comes from the new machining time. Whereas with the old machining method a total of 2.5 hours were needed to machine the five diameters, now this task is performed in only one hour. The productivity and capacity of the machine have increased accordingly. As the power consumption during helix milling is also lower than for the previous method, the spindle is protected and therefore consumes less energy.