Introduction A Computer Numerical Controller refers to a computer that reads machine code instructions in order to control a machine tool. Computer Numerically Controlled, (CNC), Machine tools are typically used for machining raw material stocks into finished designs by carrying out a series of such instructions. CNC Lathes are probably the most common use of this particular engineering. They rotate a block of material so that it can be cut, sanded, drilled or finished, with the final result being a completed three-dimensional product. In reality, CNC lathes are fundamentally the same as a regular turret lathe, but running under computer control.

History

Electric motors started to become commonly available in the early 20th century, which inevitably led to many standard lathes being converted to electric power. It was the initial stage in automating the milling or turning process, It continued rapidly during the last century as producers and industrialists increasingly wanted to improve efficiency and minimize manufacturing costs.

Constituent Parts / Components

Modern CNC lathes are a combination of a computer with a lathe machine and a controller that converts each digital signal into the desired action. Before this the instructions have to be written using specialist software to encode the required actions. The work piece is next fitted on the chuck and rotated at slow or high speeds depending on the material and the type of cut or centering required. The computer then controls the lathe through the cutting action until the finished product is produced. The latest lathes can have up to four spindles to perform multiple jobs simultaneously, which reduces production time and improves productivity accordingly.

CNC lathes are usually fitted with three jaw hydraulic chucks. Work holding is accomplished with hard jaws or bored soft jaws. Lathes may also have a collet chuck. This allows for variable size and precision holding without the need for soft jaw boring. When equipping a lathe with a collet chuck, it may be necessary to modify or change the draw bar connecting the actuator to the chuck.

Tool pieces are usually made of hard alloys such as titanium carbide and tungsten carbide, and may vary depending on the material that needs to be processed. They are used until the sharpness reduces below a predefined level. After this level is reached they are either resharpened, or replaced with a new bit.

Despite their precision, CNC lathes generally require a good operator to oversee the mechanised process. This is still a much quicker, more productive and more cost effective solution than traditional lathes could achieve. A developer is also required to compile the program commands needed to instruct the equipment in the first place.

Programming a CNC lathe firstly requires a blueprint of the item to be created. After the blueprint is analysed, the programming of the cutting tools required for making each part can then be started. Every move in three dimensions is programmed, in extremely fine detail. Great care is obviously required at this stage to ensure that no mistakes are made, as errors in live production could be very costly.

Practical Applications of CNC Lathes

CNC lathes were primarily designed for cutting hard materials spinning at high speed. They are also frequently used for boring precise holes into such hard materials. The material does not have to be metal, as other materials such as wood and plastics can also be processed quickly and effectively by a CNC lathe. They are commonly used in light, medium and heavy engineering shops for creating many of the objects we see in everyday use. There is still a place for more traditional manual and electric lathes however. Usually this is where craftsmanship is a key part of the finished product, or where low production volume does not warrant the cost of a CNC lathe.

Advantages / Benefits

CNC Lathes have rapidly replaced the older manual lathes due to their ease of programming and operation. They provide a more rapid turn-round time for complex one-off parts and ensure consistency in quality control and design tolerances. They are designed to use modern carbide tooling and fully utilize modern processes. Three further benefits are reduced production time, reduced inventory and reduced set up times. With the continuing rise in demand for engineered parts, CNC lathes ultimately give higher production volumes, with greater precision and fewer errors.

Summary

CNC lathes bring real benefits to the general population and are a perfect example of man’s technological achievements being put to practical use. Goods today can be produced faster, more accurately and at a cheaper cost than previously due to their extensive use.

This article has been written by the author, Alex Blaken. Should you require any more Computer Numerical Controller please visit his Information Product Creation resources!