You know how a lathe works if you ever worked in a machine shop, even if you didn’t operate one yourself. But maybe at some point, you toured a manufacturing facility as part of researching a career in metalworking, and now you want to find out more about these exciting machine tools. In that case, this guide is for you!
The lathe works on a relatively simple principle: You fasten a workpiece in a chuck, turn on a motor that spins the piece, feed a fixed cutting tool in one of two directions, and create a cylindrically shaped part with a flat front. Of course, this is an oversimplification of a turning operation, but you get the point.
A few decades ago, all lathes were manual turning machines where an operator determined the speed of the chuck, the depth of the cut, and the feed rate of the fixed cutting tool. These machining operations were among the most dangerous in the machine shop. Lathe operators were exposed to hot, flying metal chips, the occasional workpiece letting loose, and worse yet, getting clothing or fingers entangled in all those moving parts resulting in missing digits or worse.
The Invention of the CNC Lathe Added Automation and Safety to Horizontal Machining
At around the same time that computer numerical control—CNC milling—was changing the face of the manual milling machine, CNC lathes arrived on the scene with the promise of high production, tighter tolerances, faster spindle speeds, and shorter cycle times. And these CNC turning centers would keep their promise. Eventually, multi-axis CNC lathes would perform machining operations that were unimaginable a few years ago.
Now that you have some idea of what a CNC lathe does, let’s back up a bit and look at the basic functionality of these versatile CNC machines.
What are the Parts of a CNC lathe?
- Machine Bed: The CNC Lathe or CNC Turning Center bed is the main base on which its components are mounted.
- Main Spindle: The main spindle consists of the spindle assembly and the spindle drive system. Many of the moving parts of the CNC lathe are in the main spindle, including motors, gears, and the chuck. The C-axis drive that assists in positioning the material is also assembled with the spindle.
- Sub-Spindle or Second Spindle: Although not part of the main spindle, the optional sub-spindle works in concert with the main spindle to complete primary and secondary cutting operations, improving efficiency and production.
- Chuck: The lathe chuck is comparable to the vise on a milling machine since it holds the workpiece to allow safe and accurate machining. The chuck size determines the size of the work a CNC lathe can handle.
- Guide Way: The guideway enables the cutting tool to move horizontally and vertically and complete a smooth cutting process.
- Headstock: The headstock contains the main motor and the main spindle mounted on the chuck.
- Tailstock: The tailstock is located on the end opposite the headstock. The tailstock provides support when machining long workpieces such as shafts.
- Tool Turret: The turret provides the ability to change the cutting tools as required. The number and size of the cutting tools will determine the turret’s size.
What are the Primary Axes on a CNC Lathe?
An axis defines all the movements of a CNC Lathe, and there is a definition and purpose for each of them:
- X-Axis: The movement perpendicular to the spindle.
- Z-Axis: The longitudinal movement of the turret.
- Y-Axis: Vertical direction for milling/drilling operations.
- C-Axis: The axis that positions the part in the chuck by using the spindle.
- B-Axis: The rotation of the lathe’s milling head enables the head to perform work from various angles.
What are the Different Types of CNC Lathes?
- Standard 2-Axis Machine: Typically, these CNC lathes use outside diameter (OD) tooling to remove material from the outside of the part and boring bars to machine material from the center. As a rule, CNC Lathes have one spindle, one turret, and a tailstock.
- 3-Axis CNC Lathe: Much like a 2-Axis version, a 3-Axis CNC Lathe also has high-speed live tooling, giving the operator an option to do milling machine operations and standard turning operations and drilling.
- Multi-Axis Machine with sub-spindle or dual turrets: A multi-spindle CNC lathe has either two spindles of equal size and power or a sub-spindle that is smaller in capacity and horsepower. These machine tools allow the operator to turn both sides of the workpiece in one operation instead of removing it from the chuck and flipping it around.
- Chucking Lathe: The Chucking CNC Lathe has no tailstock and is typically confined to short and small parts because of the lack of support from a tailstock.
- Big Bore CNC Lathe: Sometimes called an oil field lathe, these heavy-duty turning machines have a larger bar capacity and are reserved for large diameter parts such as pipes, flanges, shafts, and rollers. The large spindle bore allows longer pieces to fit through the spindle.
- Swiss CNC Lathe: The Swiss CNC Machine produces smaller parts quickly and accurately, feeding the round bar stock through a guide bushing and into the tooling area of the machine.
Most of the CNC lathes on this list are enclosed to keep the operator safe and high-pressure coolant from escaping and making a slippery mess of the work area. Also, many of these machine tools will have the popular Fanuc CNC control.
How to Use a CNC Lathe
The CNC lathe operations begin with a workpiece held in place by a chuck in the main spindle like a manual lathe. The material is rotated as the mounted cutting tool removes material on the outside diameter, inside diameter, or across the face of the workpiece.
Unlike its manual counterpart, the CNC lathe operates with instructions from computer-aided drawings and manufacturing software, providing the G-code programming language to the machine tool. The machine tool can be programmed to move on various axes to get the precise dimensions and shape of the finished part.
Although CNC lathe machines have six or more axes, the basic CNC lathe operates on two axes with the cutting tool remaining in a fixed position. The two standard
axes are the Z-axis for removing material from the material’s diameter and the X-axis for controlling the depth of cut and removing material across the face of the part. Both of these are linear axes.
The material being removed by a CNC lathe machine comes off much more quickly than on a manual lathe. And the parts and products from CNC turning centers are precisely finished and can be considerably more complex. The accuracy of these machining centers makes them the favorite of the demanding automotive and aerospace industries and are also favored for prototyping.
Some multi-axis machines also have a Y-axis incorporating another turret that includes a second spindle, sometimes called a sub-spindle. This setup enables off-center milling, drilling, and tapping operations, and it eliminates the need to remove the workpiece and transfer it to another machine for secondary operations. With the help of multiple axes, these CNC turning machines can perform multi-tasking while producing highly complex parts.
What Can I Make With a CNC Lathe?
Because CNC turning operations produce parts with shapes such as cylinders, cones, and spheres, these CNC machine tools are often involved in machining shafts and pipes. However, with their versatility, CNC machining centers take on boring, milling, drilling, tapping, threading, reaming, knurling, and numerous other operations.
As a result, the list of items that CNC lathe machines can produce is seemingly endless. Here is a sampling:
- Aerospace parts
- Automotive parts (crankshafts, camshafts, pistons, etc.)
- Train parts
- Electric motor parts
- Nuts & bolts
- Baseball bats
- Gun barrels
- Cue sticks
- Candlestick holders
Who Manufactures Quality CNC Turning Centers?
CNC Masters is the manufacturer and distributor of two CNC lathes, the 1340 and 1440 models, that will help you eliminate the need to outsource work for prototyping and high production. Both machines provide machine shops with the versatility to switch to manual control quickly and efficiently, avoiding a CNC program for short runs. Also, their advanced CNC capabilities turn complex turning operations into simple designs that are programmed and executed accurately over multiple production runs.
Our turning machines are built in California and backed by the CNC Masters One-Year Warranty, or you may extend it for two more years. We also offer unlimited “Life-Long” Tech Support, step-by-step troubleshooting, and a walk-through process by email or phone, Monday-Friday during normal business hours, Pacific time, for as long as your company owns the machine. Unlike costly servo systems, our machines are easy to repair, replace parts, and maintain!