Lathes are broadly divided into benchtop or floor-standing models. (Notably, leg sets are available for some benchtop models). Although benchtop models are generally smaller, there is some overlap. So how are lathes sized?
You generally see them described as 8 x 12 inches, 14 x 36 inches, and so on. The first figure is the “swing” — the largest diameter that can be turned. Technically, it’s the distance between the headstock spindle and the lathe bed.
In practice, you can never turn right up to the maximum swing because you’re always going to be removing some material from the blank. If you want to make a 12-inch bowl, for example, you need a 14-inch swing.
The second figure is the length “between centers” — the maximum distance between the headlock and tailstock spindles and thus, the longest piece of wood you can turn.
A small benchtop lathe might be 8 x 12 inches or 12 x 16 inches and is often called a mini lathe. Despite the title, a piece of wood 12 inches around and 16 inches long is still a substantial lump. Even relatively small lathes can have considerable capacity.
At the other end of the scale are models that hold pieces of wood as large as 20 x 35 inches. You probably won’t ever turn anything near that maximum — a piece of oak that size would weigh over 200 pounds — but it gives you some idea of the possibilities.
On some lathes, the headstock can swivel, which means it can be rotated at 90° to the bed. This can allow you to make larger diameter bowls because the bed bars aren’t in the way anymore (it’s called “outboard turning”). However, an additional tool rest is required, and this is almost always at an extra cost.
Large diameter doesn’t always mean the lathe is long. There are a number of “short bed” lathes specifically for turning large bowls; you might see 36 x 18 inches, for example. However, these are far from common and really only for specialists.
