Swiss Screw Machining Industry Information
Swiss Screw Machining
Swiss screw machining is a special type of lathe machining that uses multiple tools to remove material from a workpiece. The process was originally developed to produce minute precision parts for Swiss watches that were unable to be machined using a traditional lathe. From its original function, Swiss screw machining has grown to become an essential process for producing high-tolerance components and parts.
Quick links to Swiss Screw Machining Information
How Swiss Screw Machining Works
The name Swiss screw machining may give the impression that all that Swiss screw machines do is produce screws. This aspect of their name comes from the origins of the process, which was to produce high tolerance screws. With technological advancements and computerization, Swiss screw machining has grown into a major part of industrial component production.
The process for Swiss screw machining is very similar to the functions of a lathe in that a workpiece is carved as it spins. Although spinning can be completed on a Swiss screw machine, it is only one of its many functions. With Swiss screw machining, the workpiece does not have to be rotated to be shaped or formed. The process is differentiated from a lathe by how the workpiece is presented to the tools, which is through the movement of the workpiece along the Z-axis to the cutting tools.
A unique feature of Swiss screw machines is the inclusion of a bushing and collet that hold the workpiece firmly and prevent bending or deflection. This makes it possible for tools to cut a workpiece very close to where it is being held. Additionally, unlike a traditional lathe, a Swiss screw machine can cut along 13 axes, making it possible for it to perform milling and threading operations simultaneously.
The various features of a Swiss screw machine enable it to produce intricate precision parts with a tolerance of +/-0.0002 in (0.00508 mm). Since the workpiece is placed next to the bushing, it is possible for it to have an extreme length and width ratio. The increased stability allows for high accuracy and makes it possible to cut and shape a workpiece at several points at the same time.
Types of Swiss Screw Machines
The original Swiss screw machines were automatic and machined parts after having their tools positioned. As the Swiss screw machining process became popular and computer numerical control (CNC) machining was introduced, the programming of Swiss screw machines was aided by the addition of CNC codes. Automatic and CNC are the two types of Swiss screw machining most commonly used by manufacturers.
Automatic Swiss Screw Machining
With automatic Swiss screw machining, the workpiece is mounted on a rotary slide and held in place by a collet. A disc cam rotates tools to the workpiece in a radial motion and positions the tools in accordance with any inaccuracies in the workpiece’s position. The close position of the spindle collet eliminates any problems in regard to deflected debris.
CNC Swiss Screw Machining
CNC Swiss screw machines have a CNC control unit to enter G and M codes into that directs the machining process. In most cases, the codes are developed by an engineer who sends them to the CNC Swiss screw machine. The CNC machining process makes it possible for Swiss screw machines to perform a wide range of machining processes with rotations as high as 10,000 RPM. Additionally, CNC Swiss screw machines can have more tooling with two spindles, which increases efficiency and the speed of machining.
Why Swiss Screw Machining is Used
The initial premise upon which Swiss screw machining was developed was precision, accuracy, and consistency. In the modern era of industrial production, these guide words have become more predominant and serve as the principles for manufacturing. The production of high quality and precision components is a critical necessity for the aerospace, firearms, automotive, and medical instrument industries.
The many benefits of Swiss screw machining include:
Quality Finishes
An essential factor in modern design is a smooth surface texture to avoid the need for secondary machining of components. Swiss screw machining produces finishes with an Ra factor, average roughness, of 32.
Cost
At the heart of every industrial operation is a method for limiting the costs of production. The per unit costs of Swiss screw machining are very low due to the speed at which components are produced and their quantities, which can be as high as 1000 units.
Machining
There are very few limitations on the number and types of milled features that Swiss screw machining can produce. Edges, slots, patterns, and flats can easily be programmed into a Swiss screw machine and be produced with exceptional accuracy and precision.
Precision
Precision is the reason that Swiss screw machining is so widely used. The process is capable of shaping and forming a workpiece down to the most minute and miniscule detail, regardless of how intricate. This aspect of Swiss screw machining is what manufacturers require in order to produce quality parts.
Complexity
The original purpose of Swiss screw machining was to overcome the inaccuracies produced by traditional machining, which had led to poor quality parts and components. The types of components that were being produced in the latter part of the 19th century required consistency and precision, a factor that was not available using the machining methods of the period. Swiss screw machining was developed to overcome the errors of previous machining methods and offered manufacturers the ability to produce highly complex and intricate parts with exceptional tolerances.
Rate of Production
In the modern era, lead times and speed of production are at the forefront of manufacturing. Companies that are able to quickly, rapidly, and efficiently produce components are sought after and successful. With Swiss screw machining, lead times are radically shortened and high volumes of parts can be quickly produced at the highest quality.
Conclusion
From its origins at the end of the 19th century, Swiss screw machining has smoothly moved into the 21st century. Every aspect of the machining process is performed with the highest precision and accuracy, a factor that enables producers to provide high quality parts and components at a very reasonable cost.