Chip management

By Surendra Datar
Tata Motors Limited
Pune

With auto loaders chip management becomes crucial and becomes difficult if the turning gets combined with facing. Chip breaker grooves work efficiently in turning but fail in facing because the approach angle becomes very small. This small approach angle (see red color) reduces the chip thickness thus making it difficult to break the chip. Chip breaking can significantly be improved by making the approach angle larger. In CNC machines, by breaking the cycle just before facing and going back from OD to earlier turned diameter (see black color).
By carrying out this change in the programme, approach angle becomes favorable and chips break efficiently (as good as those observed in turning). Compare blue color and black. Although some seconds will be lost in so doing, there will be no need to stop the machine and remove entangled chips on supporting centre or the part. We could not do so on a copy turning lathe. We therefore cranked the holder and increased the angle. This made the chip management much better.