WNT (UK)'s complementary ranges of solid carbide end milling cutters, its SCR (Steel Cutter Roughing) High Performance Cutters (HPC) and High Feed Cutters (HFC), introduced in 2011, have now led to the development of a hybrid, the SCR Torus cutter.
WNT's SCR Torus cutter combines the two roughing strategies of HPC and HFC cutters to create a cutter that is capable of full slot milling to 1XD and other conventional milling operations such as ramping, profiling and pocket milling, and is also capable of high feed (waterline) type milling.
These hybrid cutters eliminate the need for tool changes between the two rough milling strategies, saving cycle time and also reducing the tool inventory.
The geometry of the cutter is ground with two large 'actual' radii and one theoretical radius on the cutting edge. The first, larger radius, provides the SCR Torus with its high feed capability, while the smaller radius generates extended tool life by protecting the cutting edge from premature wear when conventional milling. These two combine to create the theoretical radius (R3D) for use when programming the cutter path in a CADCAM system. The cutters can also be used for finishing vertical surfaces using the outside diameter of the tool.
When full slot milling the deeper flute design and axial through tool air blast aids swarf evacuation, while the irregular pitch enhances surface finish by reducing vibration and the S-shape profile of the end face of the cutting edges creates a softer cutting action by shearing into the material being cut. The diameter range extends from 3 through to 16 mm, all with four flutes as standard.
WNT reports that a cycle reduction of 2.5 hours was achieved machining a mould tool. Using an indexable insert tool the operator had to be available by the machine to change inserts when they became worn. The cycle time was 3.5 hours. Running the SCR Torus cutter at a typical 160 m/min at a feedrate of 0.12 mm/tooth and depth of cut of 0.3 mm, the component was completed in a cycle time of one hour, without the need for a toolchange.