Sliding Head Machining Techniques, Insights, and Best Practices

IS IT SLIDING HEAD OR SWISS MACHINING?

The answer can often change dependent on who you speak too. Both names are applicable but describe two subtle differences from the origins of the CNC Machine type.

Sliding Head refers to the bar of material is moved with a sliding headstock then a tool pattern around the main spindle with usually at least one gang of tools but often many more and sometimes even a rotary turret.

'Swiss' refers to the lineage of the machine design. Initially, these machines were developed in the 1870’s in Bienne Switzerland by Jakob Schweizer and where aimed to service Switzerland’s watch making industry.

Since then multiple industries have adopted them due to the accuracy and speed achieved.

WHAT IS SLIDING HEAD MACHINING?

Sliding Head machining is a specialised turning process in which the material bar is secured by a collet and supported by a guide bushing.

Unlike traditional lathes, where the workpiece remains stationary, the bar stock in Sliding Head machines feeds through the guide bushing as the cutting tools move in both radial and axial directions.

This setup provides superior stability, enabling the production of highly precise components. It's especially effective for machining long, slender parts that would be prone to deflection or vibration in conventional turning setups.

A key advantage of Sliding Head machining is its ability to perform multiple operations simultaneously. These machines can execute turning, drilling, milling, and other processes in one continuous cycle, without the need to reposition the workpiece.

This multi-tasking capability not only reduces cycle times but also enhances dimensional accuracy, making Swiss-type machining an ideal solution for producing complex geometries with tight tolerances.

ESSENTIAL TECHNIQUES FOR PRECISION SWISS MACHINING

#1 - Selecting the Right Tooling for the Job

Tooling is the backbone of successful operating a Sliding Head machine. When choosing tooling, these considerations should be taken into account:

• Tool Deflection – with parts with small diameters and long lengths any vibration can really affect the finish produced. Minimising this with high quality tooling ensures distortion is minimised and parts are more consistent.
• Chip Control – tooling that has good chip control ensures the cut is more consistent meaning that we minimise burring on the part, we again minimise vibration and harmonics due to consistent pressure on the part.
• Precision – Often parts produced have very tight geometric tolerances and small geometric features, when selecting tooling, make sure inserts and milling cutters have the geometry to be capable of making what is needed.

#2 - Refine Your Toolpath Strategies

An optimized toolpath not only improves precision but also reduces cycle time and tool wear.

Efficient toolpath planning minimises unnecessary movement, improves transitions between operations, and ensures a smoother machining process.

SolidCAM is a game-changer here, offering a huge variety of toolpath options including sliding head specific toolpaths like thread whirling as well as simulation tools that let you fine-tune your strategy before running the job, reducing guesswork and ensuring we cut right first time.

#3 - Maximise Multi-Tasking Capabilities

Sliding Head lathes excel at handling multiple operations in one setup. Leverage their ability to perform simultaneous main and back spindle machining, along with milling, turning, and drilling, without stopping or repositioning the part.

Synchronisation is key; using SolidCAM’s operation sequence manager to coordinate complex multi-tasking operations and avoid tool collisions or inefficient overlaps makes things simple no matter how many channels your machine has.

#4 - Account for Material Characteristics

Each material comes with unique machining challenges - tough metals like stainless steel need specific tooling and optimised feeds and speeds compared to brass. Always consult the material's machining specs and adjust your parameters accordingly.

Correct coolant selection is also vital, this enhances tool life, generates better surface finish and can increase machining efficiency.

A common choice is a soluble oil as it has a good blend of lubrication properties and anti-corrosion, but semi synthetic or fully synthetic coolants can provide better heat dissipation.

STRATEGIC MOVES FOR LONG-TERM SLIDING HEAD MACHINING SUCCESS

#1 - Invest in Professional CAM Software

A robust CAM system like SolidCAM is essential for getting the most out of your Sliding Head machine.

It offers powerful features for turning, milling, simple part transfers, operation sequence management, toolpath optimisation, and real-time simulation of multiple channels.

As well as truly seamless integration with SOLIDWORKS which makes it easy to manage complex jobs without slowing down your workflow.

#2 - Build a Process Around Precision

Consistency is critical in Sliding Head machining by establishing rigorous quality control checks from setup to final inspection.

Standardise procedures, approaches for machining and document your best practices to ensure every part meets the specification every time.

#3 - Keep Constant Communication

It is important to make sure that there is a good communication flow between operators and programmers, any issues that arise on the machine can be compensated or changed within the CAM program.

Not having a solid feedback loop can hamper productivity and increase scrappage.

#4 - Commit to Continuous Improvement

Sliding Head machining isn’t a set-it-and-forget-it process. To stay competitive, it's ideal to continuously review your operations.

A 1% gain on a large batch can lead to huge savings. Evaluate new tooling technologies, refine your CAM strategies, and seek feedback from operators, efficiencies only become obvious when a cycle starts.

Even small adjustments can lead to noticeable gains in performance, accuracy, and cycle time.