What Is Lathe Swing?

Disclaimer: Obsessed Woodworking is reader-supported. I may receive a small commission if you purchase anything through my site.

We recently wrote about lathes and, in particular, a mandrel, a tool used with lathes that hold a work piece at the center so the spin of the piece is balanced.

This is an essential element of turnery, and it assures the work piece does not wobble or spin unevenly.  As you can imagine, your bowl or plate will not turn out well if it does not spin centered.

Today, we turn to another aspect of turnery called lathe swing.  While that may create an image of swinging lathes, it actually has to do with the dimension and size of your work piece.  It will help to know and understand various terms about the parts of a lathe, as well as its purpose.

We’ll cover that, too, in this article.

Key Points:

  • Swing refers to the size of the piece of wood that can fit without hitting either the lathe bed or lathe carriage.  Think clearance here.
  • The lathe bed is the main frame of the lathe, and the carriage is the moveable platform that supports the tool holder.
  • Your workpieces need to spin freely and round without hitting any part of the lathe, so anticipate your likely lathe projects and be sure to purchase the right lathe, with adequate swing, for those projects.

While we will mention metal lathes found in machine shops, we’ll be thinking and covering wood lathes for this piece.

As an aside, and I have mentioned this before, my younger brother is a turnery artist, and I rely upon him to guide me on lathe machines.  I remember using a wood lathe in junior high school shop classes but haven’t touched one since.

Lathe operation is well outside my skillset but is clearly in his comfort zone.  I have several of his pieces in my home and take great pride in showing them to guests.

What Is A Lathe?

A lathe is a machine tool that rotates a workpiece about an axis of rotation to perform various operations such as cutting, sanding, knurling, drilling, deformation, facing, and turning, with tools that are applied to the workpiece to create an object with symmetry about that axis.

Lathes are used in woodturning, metalworking, metal spinning, thermal spraying, reclamation, and glass-working. Lathes can be used to shape pottery, the best-known design being the Potter’s wheel.

Most suitably equipped metal lathes can also be used to produce most solids of revolution, plane surfaces, and screw threads or helices.

The main parts of a lathe are:

  • The bed: The bed is the main frame of the lathe. It supports the other parts of the lathe and provides a stable platform for the workpiece to rotate on.  At one end of the bed will be the spindle (next on this list) and chuck, and connection attributes that will hold the workpiece in place; at the other end of the bed will be aspects that hold the other end of the workpiece when needed – – think baseball bats or spindle legs, rather than blocks of wood that will become bowls or plates (further down the list)
  • The spindle: The spindle is the rotating axis of the lathe. It is attached to the bed and holds the workpiece in place.
  • The tool post: The tool post is a movable platform that holds the cutting tools. It can be moved along the bed to position the tools at different locations on the workpiece, including face-on (think plates and bowls, for instance)
  • The tailstock: The tailstock is a support that attaches to the bed behind the workpiece. It can be used to support long workpieces or to apply pressure to the workpiece.
  • The leadscrew: The leadscrew is a screw that is attached to the spindle. It can be used to move the tool post along the bed at a programmed rate.

Lathes are classified into different types based on their size, speed, and the type of work they are used for.

Some of the most common types of lathes include:

  • Engine lathes: These are the most common type of lathes. They are used for a variety of general-purpose machining operations.
  • Toolroom lathes: These lathes are designed for precision machining. They are used to make parts with high accuracy and tolerances.
  • CNC lathes: These lathes are computer-controlled. They can be used to automate a variety of machining operations.

Lathes are a versatile and powerful tool that can be used to create a wide variety of objects. They are an essential tool in many industries, including manufacturing, engineering, and woodworking.

What Are Common Wood Lathe Terms and Names?

To make sure we are all on the same page about lathes, let’s become familiar with some lathe terms and names of lathe parts.

  • Headstock: The headstock is the part of the lathe that holds the spindle. It is located at the left end of the lathe.
  • Spindle: The spindle is the rotating axis of the lathe. It is held in the headstock, and it is used to hold the workpiece.
  • Tool rest: The tool rest is a movable platform that holds the cutting tools. It is located on the carriage, and it can be moved along the bed to position the tools at different locations on the workpiece.
  • Tailstock: The tailstock is a support that attaches to the bed behind the workpiece. It can be used to support long workpieces or to apply pressure to the workpiece.
  • Carriage: The carriage is the movable platform that supports the tool rest. It can be moved along the bed to position the tool rest at different locations on the workpiece.
  • Cross slide: The cross slide is a movable platform that is attached to the carriage. It can be moved sideways to position the tool rest at different angles on the workpiece.
  • Apron: The apron is a part of the carriage that houses the leadscrew and the feed controls.
  • Leadscrew: The leadscrew is a screw that is attached to the spindle. It can be used to move the carriage along the bed at a programmed rate.
  • Feed controls: The feed controls are used to control the speed at which the carriage moves along the bed.
  • Chuck: A chuck is a device that is used to hold the workpiece on the lathe. There are many different types of chucks available, each with its own advantages and disadvantages.
  • Gouge: A gouge is a type of cutting tool that is used for woodturning. Gouges have a curved blade that is used to remove material from the workpiece.
  • Roughing gouge: A roughing gouge is a type of gouge that is used to remove large amounts of material from the workpiece.
  • Finishing gouge: A finishing gouge is a type of gouge that is used to remove small amounts of material from the workpiece to create a smooth finish.
  • Spindle gouge: A spindle gouge is a type of gouge that is used for spindle turning. Spindle turning is the process of turning a long, slender object, such as a table leg or a vase.
  • Faceplate: A faceplate is a flat disk that is attached to the spindle. It is used to hold the workpiece when it is not possible to use a chuck.
  • Woodturning: Woodturning is the process of using a lathe to create objects from wood. Woodturning is a popular hobby, and it is also used by professional woodworkers to create a variety of objects, such as bowls, vases, and furniture.

These are just a few of the many common wood lathe terms and names. There are many other terms that are used in woodturning, and the specific terms that are used may vary depending on the type of lathe and the type of work that is being done.

What Is Lathe Swing?

Now that we know what a lathe is and its various important parts, let’s address the question of this article – lathe swing. 

Lathe swing is a term used to describe the maximum diameter of a workpiece, how big it can be, that can be rotated on a lathe without hitting any other part of the lathe, including the bed.

There are two types of lathe swing:

  • Over the bed: The size of a workpiece that can be rotated over the lathe bed freely. You need the spin of the work piece to be free, smooth, continuous, and consistent at your chosen speed. Measure from the center of the spindle to the bed, and multiply it by 2 to calculate the diameter. This maximum size is important and should be considered before you spend money on a lathe.
  • Over the carriage: The size of a workpiece that can be rotated over the carriage, also called the lathe saddle, freely. The carriage is the movable platform that supports the tool holder. Measure from the center of the spindle to the top of the carriage and multiply by 2 to calculate the diameter. This swing over carriage is important, too, when considering which lathe you will choose for your shop.

The lathe swing over bed and swing over carriage is an important factor to consider when choosing a lathe for a particular project. If you need to turn a large workpiece, you will need a lathe with a large swing.

Know the maximum diameter the lathe can handle; that largest diameter will determine what lathe you purchase.

To give you some idea of these maximum diameters,  examples of lathe swings:

  • A small benchtop lathe or mini lathe might have a swing of 6 inches in diameter.
  • A mid-size, medium-duty lathe might have a swing of 12 inches in diameter.  The largest lathe machine I ever saw, touched, and worked with was a mid-size lathe machine, again in junior high school.  I don’t recall what we turned, either.
  • A large industrial lathe might have a swing of 48 inches or more in diameter.  To be honest, I’m not sure I would ever consider working with one that large.  What the heck would I turn on that one?  And how big would the work piece be on a lathe that size?  And what about lathe tool size?

The lathe swing is also affected by the type of chuck that is used. A chuck with longer jaws will reduce the swing.

When choosing a lathe, it is important to consider the size of the workpieces that you will be turning.

Know or anticipate the maximum diameter workpiece you are likely to take on as a project, and then make sure to get a woodworking lathe size with a swing that is large enough to accommodate the largest piece of wood that you will be turning.

Basically, though, lathe swing has to do with the largest piece of wood you are able to turn cleanly on the lathe that does not hit the bed or the carriage – how much space you have to ensure a clean spinning.

In retrospect, I suppose we could have answered the question with that one sentence, but that would have done a disservice to initiates, those shopping for their first lathe and are considering a lathe purchase.

Last update on 2024-02-27 / Affiliate links / Images from Amazon Product Advertising API

Please leave a comment to join the discussion