Understanding the differences in two-spindle lathes
With so much terminology in the marketplace when it comes to lathes with two spindles, the first step in the buying process often is to simply understand the subtle differences.
Subspindle, twin spindle, dual spindle, main spindle, and secondary spindle all are terms used to describe the spindle architecture inside a machine. Machine tool manufacturers will apply this terminology in different ways, depending partly on the component setup and partly on individual preference.
Main spindle. This is the main working spindle of the lathe.
Secondary spindle. Also sometimes called the pick-off spindle or back spindle, this spindle is located to the right of the main spindle and can be identical to or inferior to the main spindle.
Subspindle. When the word subspindle is used, it typically means that the spindle to the right is inferior to the spindle to the left. The inferiority comes in the form of less horsepower, a smaller chuck, and less through-bore capacity. In a subspindle-style machine, the two spindles usually face each other, allowing a transfer of some type to happen between the spindles. This enables the machine to process parts almost continuously.
Twin spindle. In a twin-spindle setup on a CNC lathe, both spindles usually are identical in specifications and capacities.
Dual spindle. Dual-spindle lathes typically are defined as having a main spindle and secondary spindle with identical chuck size and through-bore capacity, but with different horsepowers.
Two spindle. There are different types of two-spindle machines. In one style the spindles face each, and in the second style they do not. The second type requires either a manual or gantry-style loading system.