Introduction to CNC Lathes

Wish to learn all about CNC Lathes but unsure where to start? Well, you’ve come to the right place!  

For those new to the industry, the sheer variety, sizes and specialised uses of CNC (Computer Numerical Control) machines used in manufacturing can be mind boggling—from lathes, milling machines, and multi-axis machines to other machine tools.

To help you better understand what each tool is about and how you can use them, we will be starting a new series on the basics of CNC Machine Tools.

In this article, we will focus on CNC Lathe Machines, covering the following:

– Definition of CNC Lathe

– Parts of CNC Lathe

– Uses of CNC Lathe

– Programming CNC Lathe

– Types of CNC Lathes

– Prices of CNC Lathes

– Examples of CNC Lathes 

Considered the workhorses of the manufacturing sector, lathe machines have been around ever since the 19th century. Unlike its predecessors, today’s CNC Lathes are much more sophisticated and automated.

Powering factories around the world, they are used in a wide range of applications.

So, what is a CNC Lathe Machine?

Operated with Computer Numerical Control (CNC) systems and provided with precise design instructions, CNC Lathes are machine tools where the material or part is clamped and rotated by the main spindle, while the cutting tool that work on the material, is mounted and moved in various axis.

CNC Lathes are normally used for machining parts, where the material / part is clamped and rotated whereas the cutting tool is stationery mounted for OD (Outer Diameter) and ID (Inner Diameter) operations, e.g. shafts and pipes. They are ideal for parts that have same symmetry around an axis that could be chucked up (i.e. radially clamped) in the spindle.

A simple CNC Lathe operates on 2-axis and the tool is located in a fixed position at 8 to 24 station turret. The rotating action of the part is called “turning”, hence certain types of CNC Lathes are called CNC Turning Machines.

Milling (cutting tool moves around stationery workpiece), boring and tapping (a tool that cuts threads inside hole) tools are normally driven by a separate drive system inside the turret. Depending on the application, the life tools (i.e. active tool) are mounted for axial or radial operational directions. These could be found in 3-axis CNC Lathes or CNC Turning Machines.

Lathe machines with additional options such as Y-axis, sub-spindles, or specific selected options for automation are commonly called Turning Centres. These sophisticated machine tools are capable of machining complex parts – these go beyond standard OD & ID turning operations and may incorporate milling, drilling and tapping operations to complete the part in one setting. Taking a piece from raw part to finished product, such all-in-one machine tools significantly improves productivity.

What are the different parts of a CNC Lathe Machine? How do these different components of the CNC Machine Tool fit together?

In general, CNC Lathe machines comes in the following main configurations:

• Horizontal
• Vertical
• Slant Bed
• Flat Bed
• Standard
• Multi-axis
• Other types, e.g. Swiss Type, Multi-spindle, B-axis

 Depending on their configuration, CNC Lathes may have the following components.

Machine Bed

The bed of a CNC Lathe or CNC Turning Centre forms the main base for the whole machine. It is where the different components of the machine are mounted on. For example, the spindle stock which houses the machine’s main spindle; tailstock body; X and Z axis slide; optional Y-axis; and sub-spindle.

To ensure longevity, Hwacheon manufactures machine beds using high quality Meehanite cast iron. These help to limit heat distortion and provides solid mechanical stability. This ensures that the parts machined are consistently accurate.

Main Spindle

Often known as the heart of a machine tool, the main spindle consists of a spindle assembly and the spindle drive system. These are some of the moving parts of the CNC machine tool, and they include motors, gears, and the chuck (more on it later). The C-axis drive which helps to position the material will also be assembled together with the spindle.

Tool holders are normally installed at the turret disk (a rotating disk allowing tools to be positioned and switched), they include both fixed and life tool holders. The life tool drive system is built-in.

To ensure greater quality, Hwacheon manufactures 100% of its own spindles and parts of it. These can tolerate standard or higher optional rpm ranges, run with minimized vibration levels, depending on the application requirements.

Sub-Spindle/ Second Spindle

Separate from the main spindle as an option, the sub-spindle works in sync with the main spindle to complete the first and second cutting operation in a CNC lathe. This improves efficiency and throughput per cycle. When named as a second spindle, the mechanism has the same capacity and power as the main spindle.

Designed with the end-users in mind to achieve higher flexibility and performance, sub-spindles are available optionally on most of Hwacheon’s Hi-TECH Series.

Chuck

A chuck is a vice-like structure that grips the workpieces to be machined. It is attached to the main spindle that rotates both the chuck and the workpiece.

To achieve greater productivity in manufacturing, you should consider CNC lathes that offer a variety of options, allowing you to switch to the right tool for your turning jobs. Some of Hwacheon’s machine tools have the flexibility and size to accommodate extra-long oil pipe machining and other long shaft applications.

Guide Way

The guide way enables the tool to move horizontally and vertically to achieve a smooth cutting process. To ensure durability, rigidity and the highest accuracy are needed for this structure.

Hwacheon incorporates highly rigid solid box guides on all axes for its Hi-TECH line of machines to cut down time between processes and to enhance machining precision.

Headstock

Comprising the main motor, the headstock holds the main spindle where the chuck is mounted on. To ensure high performance, you need to consider if your machine tool’s headstock can handle high torque at low speed. This is an important consideration for tough materials.

For Hwacheon’s Hi-TECH Series, our gear-transmission system provides power and stability. The transmission assembly and spindle motor are also designed to limit heat and vibration transfer.

Tailstock

Tailstock are used to provide an extra support force on the other end of the component. This is necessary when machining long and extra-long work pieces (e.g. Shafts).

For Hwacheon’s Hi-TECH Series machines, the tailstock can be programmed to be positioned in semi-auto mode. This allows it to provide firm support and greater precision to the machined parts.

Tool Turret

The turret provides the possibility to change the cutting tools required for machining. Hence it is mounted on the tool turret. The size of the turret is determined by the number and size of tools that will be mounted on it.

To ensure stability and precision in machining, the turret in, for example, Hwacheon’s Hi-TECH 550 provides a powerful clamping force, offering an index time of 0.2 sec/setup for fast and more stable machining.

Some of the options available include:

• CNC Lathe Y-axis (for off-center operations)
• CNC Lathe Part Catcher (off-loading of parts automatically)
• CNC Lathe Bar Feeder / Bar Magazine (single bar used in bar feeder while the magazine is used for automatic processes involving a number of bars).
• Sub-spindle
• MC – drive includes milling, life tools and C-axis operation
• Various bed lengths to cater long shafts or pipes

 

A CNC lathe machine is normally used to perform / produce precise round shapes with both an Outer Diameter (OD), and an Inner Diameter (ID). Practically all kinds of structures could be machined with this machine tool, depending on their needs in different industries.

CNC Lathes are commonly used in industries such as oil & gas, automotive, aerospace, medical, electronics, mining, power plant, steel & paper mills, and ship building, just to name a few.

Modern CNC Lathes normally come with life tools that could work in multiple axis. For example, they could include both X and Y-axis, incorporate a second turret with different tools, or include a sub- / second spindle. These features help to be more effective and flexible for different milling, drilling and tapping operations.

The result is a complete and even complex part manufacturing process, eliminating the need to transfer the part to another machine for a second operation e.g. to a CNC milling machine or CNC machining centre.

One of the common questions asked is this: how CNC Lathes can be programmed and what software do the CNC machine tools normally use? A modern CNC lathe can be programmed in the following manner:

• Directly on the machine, using a modern CNC Programming Support System such as “Manual Guide I” (FANUC) or ShopTurn (SIEMENS).
• Off-line using a CAD/ CAM system. These often involve more complex shapes to be machined, or a series of operations.

In most cases, the CNC Lathes or CNC Turning Machines should be able to process one CNC programme while the next CNC programme is being established and programmed. This helps to improve the efficiency of the manufacturing process and saves time and manpower effort.

CNC Lathes – How Many Axis?

CNC lathes these days are available with various different axis, allowing more complex parts to be produced without the need to manually switch machines or tools. The different axis depict the way in which the machined part (or the tool) can be positioned / approached and rotated during the machining process.

2-Axis CNC Lathe

In this basic set-up, the 2 linear axes can be used to perform OD/ ID (i.e. cylindrical machining) and facing operations, or drilling and tapping at the centre of the part. However, it doesn’t permit milling to be done.

3-Axis CNC Lathe

In addition to the basic X and Z axis, C axis and life tool system are added. This allows the part to be positioned to perform standard milling operations, boring, and tapping operations. Helical milling operations involving the slow sync rotation of the part are possible.

4-axis CNC Lathe

Here, the Y-axis is added to the machine so that off-centre machining operations can be performed. This will work well for more irregular and complex operations.

5-Axis CNC Lathe

In such machines, a second Turret is added to a 3-axis CNC lathe (e.g. T2-2T). Such machines would then have 2-axis at each turret (upper and lower turret) plus the C-axis on the rotating spindle. This enable the use of 2 tools at the same time on the part, hence reducing cycle times drastically.

6 or more Axis CNC Lathe

Here, the permutation of such lathes may include the following:

• 2 x C-axis (main and second spindle)
• 2 x Turret (upper and lower turret, each with 2 linear axis)
• 1 x Y-axis at the upper turret
• 1 x Second spindle which can move towards the main spindle to pick up the part

Of course, there are machines with more than 8 axis. However, those are highly sophisticated and complex machines which aren’t normally needed for common manufacturing needs.

So how much does a CNC Lathe machine cost, and what should you ask for when requesting a reputable CNC machine tool manufacturer to quote for a CNC lathe?

Country of Origin

The manufacturer and the country (South Korea, Germany, Japan, Taiwan, China, others) where the CNC Lathes are manufactured have a large impact on the prices.

How CNC Lathes are Manufactured

This will influence the quality and performance specification of the machine, and they include factors such as the following:

• How much R&D and prototyping are invested in building the machine?
• Quality of raw materials and quality of key components as well as their origin of manufacturing?
• Do the manufacturers employ a deep manufacturing system (i.e. from foundry to finished machine, like Hwacheon) or do they merely do assembly, or even use OEM companies?
• Are the machines mass-produced? Or do they have focused lines produced for specific needs and higher quality standards

Size of CNC Machine Tool

The sizes of CNC Lathes are generally specified by the chuck size and the distance between centers. For example, Hwacheon’s Hi-TECH 200 standard machine is available with chuck size of 8” to 10” is lower in price than the Hi-TECH 230 standard machine which is also available with chuck size of 8” to 10”. However, HI-TECH 230 includes a much modern design and technology; and provides the possibilities to upgrade with various options to an even more sophisticated machine.

Design – Standard or Complex Machine

Standard machines are normally lower in price than complex ones. The latter may be the same machines fitted with additional option parts. For example, Hi-TECH 450A standard machine has a chuck size of 10”. It can be fitted with 12” and 15” chuck, i.e. Hi-TECH 450A/B/C, providing at the same time bigger spindle bore diameters. Besides theses standard machines can also be fitted with milling functions, Y-axis, sub-spindle and also a longer machine bed (Hi-TECH 450A/B/C – std / MC / YMC / YSMC / LYSMC).

Specifications

Machine prices are also influenced by the different options chosen. Adding options like Y-axis, additional motor power, main spindle torque range, guide way system (linear ball or roller, box guide way), coolant through spindle (CTS) systems (30 or 70 bar), tool setter, chip conveyors (standard or special for aluminium), or spindle bore size (especially if BB or BB+) will result in added costs to a standard machine. Additional options like special bearings, automatic tool changers (ATC) and hydraulic chucks will also impact the machine prices.

Shipping

Finally, shipping costs from the location of manufacture to the end-user will add to the machine price. This may vary from country to country. The size of the machine to be shipped will influence the packing and type of transportation (container or flat rack) used. This will in turn affect the price of CNC Lathe.

As a world-class CNC machine tool maker, Hwacheon Machine Tools has a range of different CNC Lathes and CNC Turning Centers under our Hi-Tech series 

All Hwacheon’s Hi-TECH machines have the following features :

• Precise and rigid mechanical parts, designed for strength and durability
• Wide range of specifications to meet comprehensive range of machining solutions
• Tried, tested and proven around the globe
• Manufactured by Masters in machine tool making in South Korea
• Dedicated and made-to-order custom-made machines, i.e. not mass produced
• Supported by a world-wide network of Hwacheon service partners

 

Horizontal Turning Center – Hi-TECH 230

 

The Hi-TECH 230 Turning Center is the latest edition within the Hwacheon Hi-TECH line. This modern CNC Turning Machine comes with the following:

• Available as standard 2-axis CNC Lathe or a complex powerful CNC Turning Center.
• Capable of handling high volume production or “High Mix – Low Volume” manufacturing.
• Available as A – B or C version with different spindle bore and chuck sizes.
• Selection of standard length to “L” (long) or as “XL” (extra-long) for shaft work application.
• With the optional Y-axis (4th axis) and an extra sub-spindle (5th axis), off-center operations and second clamping for complete machining is made easy in one setting.
• The powerful milling drive with 5.5Kw provides the highest application variety / flexibility, making this CNC Turning Center an all-round CNC Turn-Mill Center.
• Automation solutions are offered by choosing between bar feeder / magazine, gantry loading system or using robots.
• The special designed turret of this CNC Turning Center provides up-to 24 stations through its half index function / capability.
• A modern clean design which is compact and space saving yet provides high capacity manufacturing solutions.

 

Horizontal Turning Center – Hi-TECH 450

 

The Hi-TECH 450 Turning Center is a proven machine in the Hwacheon stable, and is one of the most sold machines within the Hwacheon Hi-TECH line. It offers the following features:

• Can be used as standard 2-axis CNC Lathe to a complex and very powerful CNC Turning Centre.
• Handle high volume production or “High Mix – Low Volume” manufacturing.
• Available as A – B or C version, with a variation of different spindle bores and chuck sizes.
• Selection of standard length to “L” (long) for shaft work or larger dimensioned parts/ application.
• With the optional Y-axis (4th axis) and an extra sub-spindle (5th axis), off-centre operations and second clamping for complete machining is made easy in one setting.
• The powerful Milling drive with up-to 5.5Kw provides highest application variety / flexibility, making this CNC Turning Centre to an all-round CNC Turn-Mill Centre.
• Automation solutions are offered by choosing between Bar feeder / magazine, Gantry Loading System or using Robots.
• The main drive (22Kw or optional 26Kw) is equipped with a gear Box, providing extreme high torque and making this CNC Turning Center standing out compare to its nearest rivals.

Horizontal Turning Center – Hi-TECH 850

 

The Hi-TECH 850 CNC Turning Center is the top of the wide range of machines within the Hwacheon Hi-TECH line. This high tech CNC Turning Center stands not only above all others in the market because of its size and weight, but because of its outstanding specification and capabilities. Where other mass produced machines fail, this technical marvel delivers excellent results.

Made by Master Engineers at Hwacheon, it offers the following:

• Available from standard 2-axis CNC Lathe to a complex and powerful CNC High Tech Turning Center.
• Capable of handling high capacity production or “High Mix – Low Volume” manufacturing of large size parts.
• Available with a Standard Bar Size of 164mm and up-to 32” chuck size; option of BB with Bar size of up-to 300mm; or as extra-large BB+ with up-to 375mm used by the Oil & Gas industry.
• Selection of standard length (2.50m centre distance) to “L” (long with 3.60m) and XL (extra-long with 5.15m centre distance) for massive shaft work or large dimensioned part / application.
• With the optional Y-axis (4th axis) off-centre operations, complex machining is made easy in one setting.
• The powerful Milling drive with up-to 11Kw provides the highest application variety / flexibility, making this CNC Turning Center a special CNC Turn-Mill Center.
• The main drive (45Kw or optional 55Kw) is designed as a direct drive system to the spindle. It provides extremely high torque (up-to 6,800Nm) and power, making this large size CNC Turning Center one of the best in the industry.
• Maximum hydraulic steady rest of up-to 510mm, boring bar sizes of up-to diameter 100mm x 1000mm yet providing full function of the special wide turret.
• Special application with bigger and larger boring bar sizes available on request.

  Wish to learn more about the CNC Machine Tools offered by Hwacheon Machine Tools? Fill in our contact form to receive our catalogue, or email us at enquiry@hwacheon.com.sg.