How does CNC Swiss Machining work?

CNC Swiss Maching - Collets

At B&F Machine Products our CNC Swiss machining technology provides live drilling and milling capabilities, and offers one of the most cost-effective and accurate solutions for producing large quantities of very small, highly intricate parts. And, while our expertise helps make us one of the best in the industry, it is the technology we use that enhances our performance.

Screw machines are automated lathes which can machine turned parts. The appellation “screw machine” might be slightly misleading, as they don’t actually screw anything in, nor do they necessarily thread materials, although this is one of their functions. Essentially, they machine components by spinning on a very quickly rotating lathe, which shaves metal down to a desired size.

There are two types of screw machines: Turret and Swiss.  The Turret type, also called a Brown & Sharpe after its first manufacturer, mounts the workpiece on a vertical ram which works into the lathe. The Swiss type, named after its place of origin where watchmakers used it for precision components, mounts the work-piece on a rotary slide.

In a 2009 article by Today’s Machining World,  CNC Swiss Machining is described:

How It Works – Why Swiss?

Today’s Machining World Archive: February 2009, Vol. 5, Issue 02

The tooling area inside a Citizen L20 Swiss type turning center. (Photo courtesy of Marubeni Citizen-Cincom Inc.)

Have parts 1.25″ diameter or less? You can make them complete on one of these sliding-headstock CNC machines.

If it’s been a while since you’ve taken a look at CNC Swiss type automatic lathes (screw machines), you might want to check them out. These days, they’re more powerful than ever. They still have the fast cycle times and flexibility that have made them the standard in many precision, high production applications. But now even more tools and more options are available, and sophisticated controls help streamline the machining process.

Citizen L720 Type VIII CNC Swiss type turning center. (Photo courtesy of Marubeni Citizen-Cincom Inc.)

Always preferred for long, slender turned parts, Swiss machines are now widely used for small, complex parts — even pieces that have no turned surfaces at all. “If the part is 1.25″ [diameter] or under, it can most likely be produced on one machine and dropped complete,” said Brian Such, customer support group manager at Marubeni Citizen-Cincom, Inc., Elk Grove Village, Ill.

How B&F Machine CNC Swiss MAchingin Works

B&F Machine Products uses innovative CNC Swiss turning machinery that moves parts along a Z-axis while the tools remain stationary (unlike conventional turning, in which the part remains stationary and the tools move). Our work pieces are held firmly within the machine, and are advanced through various types of guide bushings to achieve tighter fits and tolerances. In fact, our highly advanced CNC Swiss machining can meet ultra-tight tolerances down to 0.0002.

Different Types of Swiss Screw Machines [Source: Thomas Net ]

There are two main types of Swiss screw machines: automatic and CNC. The automatic screw machine functions with a disc cam, which rotates the tools to the work-piece bay. A collet holds the work-piece in place. The disc cams move the tools in a radial motion, but also alter headstock positioning in order to account for longitudinal discrepancies with the work-piece. The automatic Swiss screw machine features very close spindle collets, which prevent much deflected debris from becoming a problem.

CNC Swiss screw machines, also called CNC turning machines or lathes, operate largely on the same principle as an automatic Swiss screw machine, except the operation is controlled by a CNC unit. Because of the increased direction provided by the CNC, these turning machines can feature more sets of tooling, allowing for the machine to perform several operations on the same piece in a shorter amount of time. Automatic Swiss screw machines can also perform several operations, but lacks the precision and swiftness as a CNC unit. A CNC Swiss screw machine can rotate a part at up to 10,000RPM at an accuracy level of 0.0002 to 0.0005 inches.

Both automatic and CNC Swiss screw machines are relatively cost efficient for longer projects because, once properly tooled and program oriented, many machines can run under the supervision of one operator. This low variable increases a Swiss screw machine’s appeal, although preparation time can be up to an hour, so shorter projects’ fixed costs might balance out for another tooling process. At the same time, Swiss screw machines are able to do more precision work due to the tight, close quarters of the collet, work-piece, and tooling, so multiple factors are at play in process selection.

For more information about how CNC Swiss Machining can help achieve your project goals contact B & F Machine Products.

[contact-form to=’’ subject=’How CNC Swiss Machine can help us?’][contact-field label=’Name’ type=’name’ required=’1’/][contact-field label=’Email’ type=’email’ required=’1’/][contact-field label=’Website’ type=’url’/][contact-field label=’Comment’ type=’textarea’ required=’1’/][/contact-form]


Leave a Reply

Your email address will not be published. Required fields are marked *