Keyway broaching on lathes is a common thing. What is new is to speed up this operation with low stress for the machine!

 

Slot is driven by the tool turret of the machine, with the input rotary motion being converted to a translation with superimposed lift-off function. This makes programming extremely easy. The keyway broaching unit is positioned in the prepared bore – in such a way as to make the extended tappet oriented to the end position in the Z axis.

 

The depth of the slot is produced by a constant X-feed moving between 0.04-0.08 mm/stroke.

 

The speed of the spindle ranges between 400 R/min – 1,000 R/min, with one rotation corresponding to a complete stroke.

 

This way, for instance, a feather key groove with a width of 6 mm and a depth of 5 mm is produced within 7.5 sec. (800 R/min and 0.05 mm feed/rotation).

 

With this operation it is important that the chip can break at the end of the groove, that is that a cut-in or a bore exists.

 

It is not only slots or grooves, but also internal and external teeth that can be produced. This is particularly interesting for tools with partial teeth.