Comment: Automating CNC machining can solve bottlenecks

 Shorter product lifecycles across industries, including everything from smartphones to medical devices and industrial equipment, have put manufacturers under pressure to design, prototype and launch new products at a faster pace than ever before. Combining these changes with rising costs and supply chain demands has led many manufacturers to focus on reducing cycle times, cutting tooling costs, increasing output and relying heavily on post-process manual inspection.

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Automation has the potential to address many of these issues, but if implemented poorly, it risks simply shifting bottlenecks rather than solving them.

The bottlenecks

To stay competitive, manufacturers have sometimes turned to narrow efficiency metrics like reducing cutting time. However, this often ignores non-cutting delays like part loading, frequent tool changes and fixture setup time. Similarly, lower-cost tooling is likely to wear out faster, result in higher part-rejection rates and raise the overall cost per part. Producing more parts per hour is meaningless if many have to be scrapped or reworked.

Manual inspection is another inefficiency. Detecting defects after machining wastes time and material. The use of in-process inspection, and tool monitoring systems allowing machines to automatically make any corrections during the cycle is more efficient.  

Likewise, gathering metrics from machines to make data driven decisions and process improvements - i.e. monitoring overall equipment efficiency (OEE) - is more meaningful than raw output numbers.

Automation has clear benefits, but to realise them, manufacturers must consider the suite of tools that can help eliminate process inefficiencies beforehand. Otherwise, automation risks amplifying problems. If, for example, a robot arm loads a part into a fixture that still requires manual adjustment, the bottleneck hasn’t been removed, it’s just been relocated.

Case in point

To illustrate this, consider a machine shop running a single eight-hour shift. Each part takes 10 minutes to machine and another five for handling. That equates to 32 completed parts per shift. If automation cuts handling time to one minute, output rises to 43 parts. Add a second lights-out shift enabled by automation, and daily output doubles to 86 parts, a 168% productivity increase. But if a robotic gripper or pallet changer fails during the night shift and no one is available to intervene, the second shift is lost. Not only does this halve output, but more downtime is needed to resolve the fault.

It's important to understand that automated systems still need maintenance, whether it’s worn-out tools that need replacing or coolant that needs replenishing. Some machines may also need to be periodically recalibrated, as extended runtimes can lead to thermal shifts and misalignment.

Automating the right way

To avoid these pitfalls, Mazak advocates a structured approach that begins by addressing the root problems. This includes setup optimisation, scheduling, chip and coolant management, part inspection, tooling selection and fixture strategy.

Mazak machines can also be equipped with additional software and hardware to help carry out real-time monitoring and adjustments, maintaining the efficiency of automation. Functions such as Ai Thermal shield can self-compensate for thermal fluctuations. Chatter during machining can be removed using Ai Spindle to dynamically adjust spindle speeds to maintain the required finish.

Case study

Take SACMA Group, a manufacturer of cold and hot forming machines. SACMA needed a flexible solution to handle components ranging from small washers to 55-ton structural bases. By installing four Mazak HCN 8800 horizontal machining centres with 348 tools combined into a MAZAK PALLETECH automation cell with 48 pallets, they achieved continuous machining across a wide range of part sizes and geometries.

SACMA also invested in the INTEGREX series, a multi-tasking platform that combines multiple machining processes into a single setup. This reduced part handling, improved accuracy and simplified the number of steps needed during production, which had the knock-on benefit of simplifying operator training.

Solve the bottleneck

Efficiency in CNC machining doesn’t come from automating individual tasks, it comes from solving bottlenecks at every stage of production, from tool wear and workpiece handling to calibration. That’s when manufacturers can truly benefit from intelligent automation supplied by the machine tool manufacturer, achieving higher spindle uptime, reduced scrap rates and better overall equipment effectiveness.

Mark Hall is European Group Product Manager at Yamazaki Mazak UK Ltd, responsible for product strategy across the company’s CNC machining and automation systems