ITC End Mills Excel With New Trochoidal Strategies at CNF

When CNF Precision Engineering purchased its first two 5-axis machining centres and a seat of high-end CAM software to drive the 5-axis machining strategies, an abundance of cutting tools from Industrial Tooling Corporation (ITC) soon followed.

Aylesbury subcontractor CNF has been utilising a wide variety of solid carbide cutting tools from Tamworth manufacturer ITC for over a decade. However, the arrival of a 5-axis 32 pallet Matsuura MAM72-35V and a MX520 and the subsequent seats of OPEN MIND's high-end hyperMILL CAM software brought a change of machining strategy where the company is moving away from indexable cutting tools to solid carbide end mills for many of its milling processes.

Certified to ISO:9001 and AS:9100, CNF specialises in medium to high volume production of machined parts for the aerospace, medical, automotive, scientific and defence industries. With monthly production exceeding 6,000 milled components each month, CNF has 10 CNC machine tools that are running 24 hours a day and 7 days a week. Operating lights-out machining overnight and at weekends, tool life and consistency is a necessity. Whilst ITC has long provided these benefits for the Buckinghamshire Company, new machining strategies instigated with its new CAM software has enabled CNF to fully realise the benefits of ITC's range of solid carbide tools for trochoidal milling.

It's widely recognised that 5-axis CAM strategies such as trochoidal, 3D and tangential plane milling are being implemented to increase material removal rates by using the full flute length of the cutting tool and increased step-over rates. Using OPEN MIND's leading hyperMILL 5-axis CAM software, CNF has adopted many of these high volume material removal practices to improve productivity, reduce tool wear and enhance surface finishes. Since instigating new machining strategies via the CAM software, CNF has reduced roughing cycle times by over 80% with overall cycle times on steel machining being reduced by 40-50%. These huge cycle time savings would not have been possible using indexable tools, as the end user can only machine to the limitations of the insert dimension.

Commenting upon this, CNF's Production Manager Mr Mark Baron says: "We used to rough machine profiles with a 20mm diameter indexable tool at a feed rate of 800mm/min with a 1-2% step-over. With new machining strategies, we can use the ITC solid carbide end-mills at feed rates of 4 to 6m/min with a 50 or even 80mm depth of cut. On steel, we are running ITC tools four times faster than we used to run indexable tools and the material removal volume is far higher because we have much higher step-over rates too. What we didn't expect with higher material removal rates was better tool life and less stress on the spindle, but that's exactly what ITC tools and hyperMILL CAM software has delivered."

On its steel, stainless and more challenging materials, CNF has been utilising ITCs 4081 Series of long length four flute AlTiN coated end mills as a universal cutter for both roughing and finishing operations. This series is accompanied by the Widia Varimill 47N6 Series stub length roughing tool that was initially measured against a competitor tool that was witnessing inconsistent and poor tool life on production run components. With a tool change required every 30-40 parts on the Matsuura 15 pallet H+300 machining centre, CNF needed better tool life and ITC delivered it. The Widia Varimill 47N6 Series stub length roughing tool now processes over 100 parts with the tool still performing well. For a production environment with machine tools running over 120 hours a week, this consistent tool life and reduced machine downtime is invaluable for CNF. For implementing full depth machining strategies for maximum material removal rates, the Aylesbury subcontractor has also been implementing the Widia Hanita Varimill 4717 Series of extra long tools that are machining at the full 100mm depth of cut.

Commenting upon this impressive performance, Mr Baron continues: "The tool life on the ITC end mills has always been impressive, but since applying these new machining strategies the ITC tools have really stepped up and exceeded our expectations. They are outstanding. There are some ITC aluminium tools that were installed in our latest Matsuura MAM72-35V 18 months ago and they still haven't been changed despite being used on a daily basis. Most of the steel end mills are lasting from 3 to 9 months and when this facility is running 24/7, we know the tools are being pushed hard and often. With regard to the ITC trochoidal series of tools, we have trialled tens of different tools from numerous vendors and ITC always outperforms or outlasts everything else we try."

The performance of the ITC aluminium range is unsurpassed. The tool life, consistency, surface finishes and material removal capabilities of the ITC aluminium series is the reason why CNF is using ITC's 2041, 3091, 3081, 3021 and the Widia Varimill 4503 series in diameters from 3 and 4mm through to 20mm diameter. This variety of 2, 3 and 4 flute high helix end-mills with extra long and even stub length tools have certainly made an impression upon CNF.

As Mr Baron concludes: "Almost 60% of our cutting tools are supplied by ITC and we have been extremely happy with the tool life for a number of years, but what has really impressed us is the ability of the tools to continually perform when we are drastically increasing and pushing our machining parameters through new boundaries. ITC's trochoidal milling tools with their innovative geometries and harmonic flutes seem to last an eternity and that can only be a good thing for our machine utilisation rates, productivity and the reduction of tooling costs."