Metalworking lathes are machine tools that do turning operations to create cylindrical shapes, including spheres and cones. Lathe machines are an essential part of most machine shops since lathe work is usually an integral part of their operation.
There are two basic types of lathe machines: the traditional engine lathe and the computer numerical control (CNC) variety. Although both have their place in a modern machine shop, there’s little doubt that the CNC lathe has become an indispensable machine tool because of its high-speed turning capabilities and its high precision.
The CNC lathe machine is a precision lathe that machinists use to complete various metalworking projects, usually those high-volume components that require accuracy and repeatability. But even if you are only shopping for a standard engine lathe, you’re making a substantial investment, and there are some things you should know before you purchase it.
Here are eight tips to help you make a decision you won’t regret:
Tip One: Determine the Size of Lathe Machine You Need
Lathes are measured in terms of swing and size, often given as a pair of numbers (i.e., 12 x 20). The first number, the swing, is the distance between the center of the headstock and the lathe bed. It’s the maximum radius of a workpiece that can be mounted between centers on that lathe machine. If the radius on your workpiece is 15 inches and your lathe has a swing of 12 inches, then the workpiece is too big to fit between centers on your lathe.
The second number is the distance between the headstock and tailstock and is often referred to as bed size. In the example above, the bed size would be 20 inches.
Tip Two: Ensure Your Machine Shop Can Handle It
Even lathes with small bed sizes can be relatively large, weighing hundreds of pounds. Floor-mounted, heavy-duty lathes can be even larger, possibly weighing thousands of pounds depending on the size. Before buying one, measure the floor space you have and ensure the lathe machine’s footprint doesn’t exceed that area.
Lathes machines come in all sizes, from small bench lathes to large, room-sized industrial CNC lathes. Consider the type of lathe operations you’re anticipating, and position your new lathe machine on your shop floor accordingly.
Make sure your company has enough power for it! Lathes require a lot of electricity. You probably already have the necessary power capacity if you’re purchasing a new metalworking lathe for your machine shop. But if you’re adding a smaller mini lathe or benchtop lathe machine to your home workshop, double-check the energy requirements.
Tip Three: Learn the Basic Parts of a Lathe Machine
Ever wondered what a CNC lathe machine is? A lathe machine is typically composed of four primary parts:
- The lathe bed can be either fixed or pivoted. The lathe bed holds and supports the structure of the lathe. The workpiece is mounted in jaw chucks fixed onto the headstock. The workpiece can also be mounted between centers in the headstock and tailstock, allowing it to spin freely above the lathe bed.
- The headstock holds the workpiece in place during machining.
- The tailstock supports and provides the clamping action for long pieces of material.
- The lead screw of a lathe machine advances the lathe’s carriage in sync with the rotation of the spindle. Its most important contribution is making threads with a specially designed turning tool.
When a workpiece is held by the headstock and tailstock, it is “between centers.” Sometimes, the lathe bed has a removable piece below the headstock to allow turning operations on a workpiece that exceeds the lathe machine’s stated swing radius.
There are several types of lathes. Engine lathes and turret lathes are your standard powered lathes. Most lathes work with various materials but are often divided into the categories of metalworking lathes or woodworking lathes. Even though they may be high-quality machine tools, wood lathes are typically not as heavy-duty as their metalworking counterparts.
Tip Four: Understand the Lathe Machine’s Capabilities
Before buying a lathe, it would be wise to figure out what type of lathe work you intend to take on and make sure the new lathe is designed for those lathe operations. For instance, if you’re buying the lathe machine for turning operations on a 48” long crankshaft, don’t buy one that maxes out at 44”.
People have been using lathe machines for centuries. They were first used in woodworking, but in the 1800s, Henry Maudslay modified the lathe for metalworking, adapting to industrial settings during the Industrial Revolution. Engine lathes and CNC lathes have increased in size and power over the years, but they have also advanced versatility with the advent of Computer Numerical Control technology.
The workpiece rotates on a spindle with a lathe machine, while a cutting tool, mounted on a tool post and fixed on a cross slide, completes the turning operation on the workpiece. This rotating spindle is why lathe machines are ideal for anything with a cylindrical shape. They are also capable of threading, drilling, reaming, boring, sanding, and knurling.
Today’s precision lathes are vital for aerospace, automotive manufacturing, furniture making, and toolmaking. Because of their versatility, lathe machines can handle a broad range of tasks. Many have variable spindle speeds and tool holders that allow operators to change the tooling mid-operation.
Modern toolroom lathes also have high versatility, especially when equipped with CNC lathe technology. These machines can perform complex machining operations that other machine tools cannot handle. Along with milling machines, lathe machines rule the modern machine shop.
Tip Five: Choose a Belt Drive or Direct-Drive Spindle for Your Lathe Machine
The spindle on metalworking lathes is either belt-driven or direct-drive, but the belt-driven type is part of the classic generation of lathes. Direct-drive spindles provide variable speed much faster than the belt-driven type, resulting in shorter cycle times. With a direct-drive spindle speed lathe, you could go from 0 to 6,000 rpm in half the time of a lathe machine with a belt-driven spindle speed. That being said, the belt-driven lathes are still a fine option and provide the power and accuracy required by many machinists.
Tip Six: Look at Spindle Speed, Horsepower, and Torque
Modern CNC lathes are designed to handle a specific range of diameters. Most machine shops buy a machine for a maximum workpiece diameter. For example, if you’re cutting 2-inch-diameter bars, the lathe machine will be designed for turning operations on smaller diameters using 6,000-rpm spindle speeds and the correct amount of horsepower and torque.
On the other hand, larger lathe machines will have higher torque because of the weight of the workpiece in the jaw chuck. Bigger workpieces require slower spindle speeds and more torque.
Tip Seven: Consider the Turning Tools You’ll Need for Your New Lathe Machine
Although your lathe machine is a big-ticket item, it’s not all you’ll need to purchase. Your lathe will probably come with a jaw chuck, but you should have a faceplate for certain types of lathe work. You’ll also need various cutting tools, including, but not limited to:
Carbide turning tools
- Boring bar
- Chamfering tool
- Facing tool
- Parting tool
- Grooving tool
- Thread-cutting tool
- Knurling tool
Tip Eight: Buy a CNC Lathe That Gives You the Most Value for the Price
CNC machines are expensive but incredibly powerful machine tools that add speed and versatility to any machine shop or home workshop. CNC Masters offers two CNC lathes that meet all the speed lathe and precision lathe criteria. These CNC lathes are built in the USA and come with excellent customer support.
No more outsourcing work to produce prototypes or complete large projects:
- Powerful size 34 Z-axis micro-stepper motor within 1500 in/oz. of torque
- Very accurate with micro-stepping motion
- X & Z Direct Drives without timing belts to adjust
- X & Y Zero Backlash Ball Screws with Pre-loaded ball nuts to eliminate play
- Full 2-axis coordinated motion control on bipolar motors – true interpolation
- Transition between CNC lathe and engine lathe modes
- Digital readout display of the X & Z counters in English or metric
- CNC Masters custom software is included
CNC capabilities transform complex manual turning applications into an easy-to-program language to run a complicated part accurately on production runs.
- Versatile machine that instantly converts from CNC lathe to traditional engine lathe mode
- 40″ Distance between centers with a 14″ swing over the lathe bed
- Full 2-axis coordinated motion control on bipolar motors – true interpolation
- Home Reference sensors on the X & Z Axis
- 2 HP main spindle motor
- Digital readout display of the X & Z counters in English or metric
- CNC Masters custom software is included
