Turning

Turning: A Machining Process

Traditionally the term “turning” refers to one of the most basic of machining processes. In this machining process, a lathe spins or turns the part or workpiece and removes material in chips with a stationary tool to reduce the outside diameter. While this scenario implies that the tool bit is moving or traveling on a parallel axis to the spinning workpiece turning can also be used to machine contours as well if CNC technology is utilized on the lathe. The turning process can be used in the machining of a prototype or in a large production run. Very close tolerances can be held during the turning process.

Often multiple turning cuts are required to turn the part’s outside diameter into tolerance. A turning rough cut removes as much material as possible to speed the turning process and bring the part within the range of a finish cut. Sometimes if a small turned diameter is required from a large piece of stock then multiple turning rough cuts may be utilized.
A turning finish cut refers to the last one or two cuts which bring the part to its final size – within the specified tolerance. These cuts are typically very shallow and special attention should be paid to the parts final finish at this time. The final finish will be greatly affected by the condition of the cutting tool and the feed and speed rates at which the lathe is operating. Again CNC technology has maximized the efficiency of tool usage and eliminated the wasted time of manual operations.

Turning is just one of the machining processes that lathes are capable of. Other processes include: facing, boring, center drilling, drilling, threading, reaming, knurling, cutoff, parting and taper cuts among others.

CNC Turning

The addition of Computer numeric control (CNC) to lathes has enabled the turning process to achieve new heights in productivity and in the creation of highly precise parts. CNC lathes are equipped with a computer consisting of one or more microprocessors and storage units, a user interface for programming and other interfaces that enable the CNC lathes to work in conjunction with CAD/CAM software systems. All of this enables a CNC machinist to instruct the CNC lathe to execute the exact movements necessary to create the precision turned part. Productivity has been further enhanced by the addition of live tooling and multiple spindles.

CNC turning is an economical manufacturing process because it requires very little time or attention from a machinist once the machine, program, and tools have been set up. Operators only need to load materials and make any adjustments to the design parameters in order for a CNC turning operation to run unattended for a certain period of time. CNC turning is an efficient and quick way to precisely produce detailed parts.