Computer numerical control (CNC) has been incorporated into a variety of new technologies and machinery. One such machine of this sort that is used for a wide array of production processes is known as a CNC lathe.
Due to technological advancements, CNC lathes are quickly replacing some of the older and more traditionally used production lathes, such as the multispindle. CNC lathes come with a number of benefits. They can be easily set up and operated. They offer tremendous repeatability, along with top-notch accuracy in production. The very act of cutting any material using a lathe machine is called “Turning”.
A CNC lathe is typically designed to utilize modern versions of carbide tooling and processes. A part can be designed for customization, and the machine’s tool paths are often programmed using the CAD or CAM processes. However, a programmer can manually design a part or tool path as well. The resulting G-Code computer file is then uploaded to the CNC machine, and the machine will then automatically produce the desired parts for which it was programmed to design.
A CNC lathe is controlled by a menu-type interface on a computer. The operator who manages the process can actually see a visual simulation of how the machine will function during the production phase. Thanks to this technology, the machine operator generally does not need to know as much about the specifics of the machine he or she oversees compared to what machine operators must know about more traditional lathes that require some manual labor.
CNC lathes are designed in a variety of ways, based on the manufacturer producing the machine. However, most have some significant similarities in their composition. A turret is a part of the machine that holds the tool holders and indexes them accordingly. The spindle is designed to hold the work piece. In addition, there are slides that allow the turret to move in multiple axes at the same time. CNC machines are typically completely enclosed for health and safety reasons of any operators present.
There has been considerable growth in the CNC machining industry, particularly when it comes to the design and use of CNC lathes. Different lathe manufacturers utilize a variety of user interfaces, which can be a challenge to the operators. But these systems are mostly based on the same principles across the board since a CNC lathe is programmed to perform similar functions in terms of what it is intended to manufacture.
Like other CNC machines ,CNC lathes have become a major part of the manufacturing industry in recent years. So, it is expected that the operations of such machines will continue to improve and carry significant weight in this field.
Uses of CNC lathe Machines
There are numerous use cases where lathe machine is used. It ranges from industry like automotive, electronics, aerospace, firearm manufacturing, sporting and many more. One can use a CNC lathe machine for shearing out a metal and also to produce plane surfaces and screw threads.
There are also ornamental lathe machine which are specially designed to work on intricate designs like 3-d products. In a CNC machine, the material is tightly secured using clamps and collets. A lathe machine is also used for metalworks, wood turning and even glass work.
Few products that you can make using a CNC lathe are
- Sign Boards
- Musical instruments
- Gun Barrels
- Baseball bats
- Dining Room Table and chair legs
Parts of Lathe machines
A lathe machine consists of several parts that are attached to each other. A properly assembled lathe machine is very important since there is a lot of resistance that happens when a lathe machine is operating of heavy metals. Let’s have a look at the important parts of the lathe machine:
Lathe Machine’s Stand and legs
Since lathe machine has to work on a lot of different materials, it needs to be flexible enough to take all that resistance and that’s where strong lathe legs come in picture. A lathe leg holds the machine in fixed position and they are also important for the purpose of flexibility when it comes to adjusting the working height.
This is one of the important parts of a lathe machine. A headstock comprises of three main things: spindle, speed change mechanism and gear shifts. A headstock is usually the strongest parts as it houses 3 main parts of a CNC machine and it has to bear a lot of vibrations and resistance due to the CNC machine operations.
A spindle is housed in the head box and is attached to the pipe that is then linked to the chuck. The chunk holds the workpiece and also makes it twirl around as per the requirements of the finished product. There is even a formula to decide the cutting speed of spindle, it is determined by
4xSFM/ D = RPM
SFM = Surface Feet per minute(Cutting Speed)
RPM= Revolutions per minute
D= Diameter of the work in inches
A gearbox is the part of CNC machine that is responsible for controlling the speed of the motors. It is housed in the headstock and turns the chuck.
The tailstock is located opposite of a spindle. It is a movable part of the CNC machine and can be changed as per the requirement of the finished product. The tailstock is made up of a barrel which can move either forward or backward. The barrel can also be used to support the material.
A carriage rotates in either right or left direction and is made up of saddle, composite support, traverse slide and top glide. It is an important tool which helps mount the tool post.
A saddle is located over the carriage of a CNC lathe and it helps the cross slide to move backward of forward on a lathe machine. It is usually in H shape.
The composite gives support to tool post and is a helpful component used when you are working materials that required sharp angles. It is located over a cross slide and helps in swivelling.
Similar to composite glide, traverse slide is located over the carriage and moves in backward and forward direction on saddle. You can use the traverse slide to engrave on hard metals using the hand wheel.
The tool post is located over the composite rest and is used to clamp your engraving tool.
A lead screw is a long shaped rod that has threads and is located on machine bed. This is a very helpful part of the CNC lathe machine which helps do automatic feed to the carriage from the stock head till its tail. It’s mainly responsible for carving out the threads on the workpiece.
The apron is located in front of the saddle and has quite a few parts attached to it like hand wheel and lever systems which help you adjust the carriage rotation on the bed.
The bed is one of the most important parts of a lathe machine and is one of those parts which rarely moves. It is usually fixed in a position and supports other parts of the CNC machine such as headstock, tailstock, carriage and many others.
Type of lathe operation
Usually there are quite a fixed number of operations that are conducted using a lathe machine. Some of them are turning, cutting, sanding, grooving etc. Even before you conduct any operation on a CNC lathe machine. You should be aware about terms like cutting speed, depth of the cut and feeds. Once you know the nature of the operation and are fully aware about the input details then only you should go ahead with any operations since any small mistake can prove to be fatal.
This is one of the easiest lathe operations where the material of metal is sheared from the end so that it can fit in the right angle of the axis and get rid of any marks
This is an operation where you simply narrow the shape of a metal to a cone shape using some compound slide. In order to change the angle of the operation , you can do so by adjusting compound slide.
Some widely used Lathe Machine processes and uses
- Step turning
- Taper Turning
- Threading process
- Boring process
- Drilling Process
- Reaming Process
Whenever you have to cut a material parallel to the axis then you use this operation. This allows you to decrease the diameter of the metal.
Some tools which help in conducting different lathe operations are:
- Grooving tool
- Cut-Off blade
- Parting blades
- Boring bar
- Side tool
- Carbide tip tools
Types Of Lathe Machines
CNC Lathe are generally of two types: vertical Form lathe machines and Horizontal lathe machines.
CNC Vertical Lathe
In a vertical lathe machine, the workpiece rotates in an upright position pretty much like you would see when a potter moves the pottery wheel, it allows the spindle to cut at hard to reach angles and positions. A CNC vertical lathe machine is used to operate on large and heavy materials, so huge that they are loaded with cranes. Another advantage of a vertical lathe machine is that gravity always favours its operations which means throughout the operation of the machine, the workpiece is always stable. This allows for better spindle movements and accurate cutting. On the price point, such machines are very expensive.
CNC Horizontal lathe
The CNC horizontal lathe is the one that you mostly see in workshops. These machines rotate a particular piece of metal in a cylindrical manner and while the entity rotates, CNC horizontal lathe machine operates on the material using tools to give it the desired form and shape. Such machines also tend to have larger footprint than vertical CNC lathe machines. Even the chuck in horizontal CNC machines hold the object vertically. These types of machines are usually used for lighter materials.
How to choose the right CNC lathe machine?
Choosing the right CNC lathe machine can be a hectic task. There are quite a few factors you need to consider like the quality of clamps since they hold the workpiece steady. You also need to check the tolerance level of the CNC lathe machine since it will undergo a lot of rough operations. Also when it comes to choosing the right kind of CNC lathe, you need to check the nature of your output and go for it accordingly. Last but not the least is the budget. Let’s have a look at some of the factors to keep in mind when choosing a CNC lathe:
Weight plays a very important role in choosing a CNC machine since if your machine is on the heavier side then its a clear indication that it will survive the rigorous vibrations and other operations which impact the effectiveness of a CNC lathe. Do not go for a lightweight CNC lathe as it can get out of balance very easily and impacting the result of your output. Go for cast iron if you can.
Swing and Bed Measurement
The swing measurement is the maximum amount of diameter of any material which can be cut or machined on a lathe. The measurement takes place from the bed of the lathe to the center of the spindle. A bed measurement is the maximum length of the workpiece which can be determined by knowing the distance between centers. This measurement will help you know which CNC lathe to look for based on your desired output.
Types of Stands and Tool Storage areas
The stand is the base on which the whole CNC lathe relies. If you are looking for a small table top lathe then a stand may not be very important but if you will be working on bigger projects then you should be very careful regarding the whole design of your stand. Since the CNC lathe undergoes a lot of vibrations, go for a material that will absorb most of it. Also, it is always better if you have a tool storage box with your lathe. This will add weight to the machine which means less vibrations.
The Headstock and Bed
The bed of any CNC lathe machine is usually made from cast iron bars and it is connected to the headstock such that the tool carriage and tailstock can move parallel with axis of the spindle. When buying a CNC lathe machine, you need to check that the bed is strong enough since the entire operation of things rely on the bed. Next important thing to consider when buying your first CNC lathe machine is the headstock. Always go for a cast iron headstock as it will give the entire machine a solid rigidity.
Headstock spindle is the part of the headstock which rotates the chuck and hence it can be thought of as the heart of the whole machine so pay special attention when it comes to choosing the spindle for your CNC lathe.
Lathe Motor and Drive
If you choose the correct lathe motor for your CNC lathe, it can have a major impact on how well the output comes out. If you are just starting out then you should pay special attention to the lathe motor. For smaller operations, go for a lathe motor that has as little as ⅓ HP(horsepower). Always go for high quality lathe motors because this is one thing that can worn out very quickly if you buy a cheap one.