How to buy a Lathe

By Alan Lacer

Are you driven to turn large, green bowls or are you more intrigued with pens and small boxes? Maybe you only want a lathe for making table legs and chair parts. Perhaps you want to do a little of everything. Answers to these questions will help you choose the right lathe.

Big Projects

If you're inclined to bowl turning (especially diameters greater than 12 in. and plenty of green stock), then look for these features: plenty of horsepower (minimum of 1 1/2 hp), low end speeds under 500 rpm, hefty bearings and shafts (usually 1 1/4 in. or larger), capacity for large diameters (at least 16 in.), sturdy legs or stand, tool rests and tailstocks that lock securely and are easily adjusted, spindle lock (simplifies the process of mounting and removing faceplates and chucks), and considerable mass (300 pounds or more).

Small Projects

If your passion lies at the other end of the spectrum, with pens, miniatures, lidded boxes and the like, there are any number of fine mini lathes on the market. These are excellent if you have very limited space and portability is a priority. Look for higher top end speeds (2,400 rpm and faster), ease of moving the tool rest and tailstock, ease of speed changes, ease of mounting on a table or bench, and weight (under 60 pounds if portability is a major factor). However, don't buy a small lathe just for small work. Large lathes are excellent for even the smallest miniature work!

Everything in Between

If you intend to primarily make furniture components, balusters, handles, or lamps, then you want a lathe with at least 36 in. between centers, speed range between 600 and 2,000 rpm, and a headstock and tailstock that accept Morse taper drives (#2 is most common) and accessories.

If your interests are broad and you intend to do a little of everything, or you're just getting started and don't even know what you want to do, consider a standard lathe. These are great starter machines that don't require a huge investment several good ones cost less than $600 and will do just about any type of turning, except large bowls. In this category of lathes you frequently find 12 in. maximum turning diameters (swing), approximately 36 in. between centers, and a speed range of 500 to 2,000 rpm. Look for a standard lathe with a common spindle size and threads because it will be much easier to find accessories. The most common is 1 in. dia. with 8 tpi (threads per inch), but 3/4 in. x 16 tpi and 1 1/4 in x 8 tpi are also popular. The same is true for spindle taper: No. 2 Morse taper is most common, and accessories for it abound. This allows the use of common accessories or upgrades such as live centers and Jacob's chucks.

Keep in mind this basic principle: larger lathes give you more freedom. Even the smallest miniatures can be done on a big bowl lathe.

Speed and Power

The power you'll need in a lathe depends on the mass of the object you wish to turn and the tool you will be using. Here's a rule of thumb: For an all round lathe, choose between 3/4 hp and 1 hp. For mini lathes you can get by with 1 /4 hp, but l%2 hp is better. For work under 12 in. or less (especially green wood bowls), 3/4 hp is sufficient. For a heavy lathe choose at least a 1 1/2 hp.

Speed and Speed Changes

How fast you turn is a function of the diameter of the work. Peripheral speed is more important than spindle speed. At 800 rpm a pen blank seems to hardly be turning, while at the same speed the rim of a 20 in. bowl is screaming. As a general rule, the smaller the diameter the higher the speed; the larger the diameter the slower the speed. So, on a pen making lathe you'll rarely turn below 600 rpm but you often may wish to crank it up to 2,400 rpm. On a large bowl lathe you may seldom turn above 1,200 rpm, but you might want a low end speed of 300 rpm or less for roughing large diameters.

There are three common methods of speed control:

  1. Belted pulleys for manual speed changes. Belted pulleys, whether V belts or flat ribbed belts, usually give three to eight different speeds. The advantage of this system is simplicity, economy and durability. The disadvantage is that changing speeds is awkward and there is only a limited range.
  2. Mechanical variable speed, which usually offers a range from 500 to 2,500 rpm. Mechanical variable speed lathes have been around for more than 50 years. By simply moving a lever you get an infinite number of speed variations within a fixed range. The downside is the system is noisy and it can only be adjusted with the lathe running.
  3. Electronic variable speed, either AC or DC. These often give a range from 0 to 3,000 rpm when combined with belted pulleys and reverse.

 

There are pluses and minuses to each variable speed system.

Reverse is another speed control option that some turners like on a lathe. They believe that a better surface is achieved if the work is sanded in both directions a belief not held by all turners! Noise can be a problem with both mechanical and electronic variable speed drives. In a quiet place, turn on the lathe you're considering and try out speed changes. Be sure you'll be comfortable with that noise level in your own shop.

This article originally appeared in the
American Woodworker in Fall 2000 #83 issue.