Gangs vs. turrets: Turning Performance

If you’re shopping for a Swiss-style CNC lathe, the available options and machine configurations are truly staggering. Spindle speeds that compete with many machining centers, convertible spindles that turn a sliding-headstock machine into a chucker, thread whirling capabilities, laser cutting heads and enough axis letters to become the next Words With Friends champion.

For those unfamiliar with Swiss-style lathes, one option that may leave you scratching your head is the choice between conventional turret-mounted and gang-style, slide-mount toolholders. Conventional CNC lathe owners might lean towards the former, but each technology has its own merits that deserve careful consideration.

Turrets offer excellent rigidity, flexibility and tool selection.
Here, dozens of tool positions are available on the twin turrets
of this Cincom M-series Swiss-style CNC lathe.
Image courtesy Marubeni Citizen-Cincom.

As a rule, slides are most common on small Swiss-style lathes with spindle capacities from 7mm to 16mm (0.276″ to 0.630″). Machines in this size range are typically less expensive than larger, turret-style machines for several reasons. For one, there are fewer moving parts on a slide mechanism, which makes the machine simpler to build.

And as Jeff Walz, president of machine tool distributor Eurotech, Brooksville, Fla., warned, a turret machine has additional costs. “Because of all the adapters and blocks that go with a turret, you can easily get a $20,000, $30,000 toolholder bill in addition to the price of the machine.”

Although turrets can cost more to tool up, this is easily countered by greater flexibility. “Turrets just give you tons more tools—some have upwards of 35 stations,” said Brian Such, customer support group manager at Marubeni Citizen-Cincom Inc., Allendale, N.J. “They’re also more rigid, with larger shank sizes and more power available on live-tool stations.”