A user and machine-friendly self contained broaching unit capable of being installed on a wide variety of CNC lathes is now available from Horn UK.  The EWS-Slot device, developed by German lathe tooling specialist EWS in co-operation with Paul Horn GmbH, simplifies the application of in-cycle broaching on turret-equipped CNC lathes.

The Horn broaching system, introduced four years ago, has shown itself  to be of significant value to manufacturing industry.  It is highly flexible and has proved capable of very high levels of accuracy and repeatability when generating slots and keyways.  Uses range across small and large scale applications on a wide range of materials.

In most instances to date, the Horn tool has been mounted in a fixed station on the lathe’s turret or platen.  C-axis positioning is used to locate the workpiece radially and the broaching operation is carried out using Z-axis movement with feed per stroke set using the X-axis; The X axis is also used to lift the tool at the end of the cutting stroke for the return stroke.

Many successful applications have been developed using this method.  However it does require that the saddle/turret assembly to be in constant reciprocating motion throughout the broaching cycle and demands careful set-up to eliminate risk of tool/workpiece collision.

Broaching unit EWS-Slot allows the broaching process to be handled in much the same way as a powered milling or drilling operation; it also consumes less power and reduces lathe component wear and the relatively low mass of the moving parts assists acceleration to the required cutting speed.  The unit occupies a powered station on the machine’s turret and this provides the drive.  Broaching stroke of 30 mm is available with cutting speed regulated by the turret motor’s speed. Lifting of the tool for the return stroke is an integral feature of the mechanism.

As a result, broaching operation programming simply requires specification of the C-axis and Z-axis position, turret motor speed and X-axis feed per stroke needed to achieve the specified groove depth. Grooves up to 10 mm wide and 30 mm length can be generated using the system, which is compatible with over 200 types of CNC lathe.

Application editorial link for: Broaching Cycle on CNC lathes.