CNC processes, Lathe machines and their types

A lathe machine is used for shaping the material into the desired form by removing excess material from a given workpiece. It also performs knurling, deformation, metal spinning, woodturning, thermal spraying and metal working.

CNC machining processes have various functionalities. CNC turning uses a helix path for cutting the material whereas CNC milling uses rotary cutters to cut material. Lathe is one of the earliest tool used for this purpose.

Following are main parts of CNC Lathe machine:

  • Carriage is used for mounting and moving the cutting tools vertically or horizontally on the bed for cutting smoothly.
  • Headstock holds gear chain, driving pulley, spindle etc.
  • CNC control panel stores the CNC instructions and programs. The CNC machine is operated by a CNC expert.
  • Chuck is attached to spindle and is used for holding the workpiece.
  • Bed is a heavy structure made of cast iron and steel scrap where different components are mounted.
  • Main drive motor drives the entire machine by rotating the chuck.
  • Main Spindle is fed with stock via a headstock.
  • Tool Turret comes in different sizes depending upon the number of tools to be mounted on it.
  • Tailstock is used for drilling.

CNC Lathe machine works by first checking it for faults and then attaching a cylindrical workpiece to the chuck. Spindle is then given a required speed for rotating the chuck and the workpiece. Speed should be given carefully to prevent any cutting errors. Cutting tool should be carefully located at the desired feed by moving the tool turret and carriage. Move the carriage to remove excess material and obtain the finished workpiece.

There are various types of Lathe machines:

  • Gap Bed Lathe: It has a section in the bed which can be removed in order to adjust workpiece.
  • Engine Lathe: It can work with different feeds and speeds, with low-power as well as high-power operations and with different metals.
  • Speed Lathe: It is a light machine operatable in three or four speeds. It is a simple machine having headstock, tailstock and tool turret.
  • Tool Room Lathe: It is operatable in a number of feeds and speeds and known for its finishing.
  • Turret Lathe: It has a tool holder to perform many operations on a single workpiece which saves time.
  • Bench Lathe: This type of lathe machine is mounted on a workbench for conducted lighter jobs and is smaller than other lathe machines.
  • Special Purpose Lathe: Crankshaft lathes, bench-type jeweler’s lathes, multi-spindle lathes, automatic lathes and duplicating lathes are some types of special purpose lathe machines which perform a heavy-duty production of identical parts.

Centre Lathe uses a set of gears operated by a liver. These gears manage spindle speed.