Rather than ask for in-depth technical support from its usual local distributor that sells multiple tooling brands, it instead called upon Jason Gardner, the local application engineer for Mitsubishi (MMC Hardmetal; 01827 312312).
Formagrind’s shopfloor manager, Mike John, takes up the story, explaining how the ground was laid prior to receiving the order: “Our tooling spend wasn’t truly measured or qualified and we set about using the experience [of] Mitsubishi to set performance parameters and structures.
We initially trialled Mitsubishi’s face-mills with success. Jason from Mitsubishi then recognised that our existing aluminium roughing end-mills were also under-performing, compared to the potential of Mitsubishi tools. He implemented the Alimaster aluminium roughing end-mill range on a long-term satellite project for a major aerospace customer; the material removal rates were nothing short of brutal. The success of the face-mills and the Alimaster cutters gave us complete confidence in both Mitsubishi tools and the local engineer.”
That confidence led to sales; Mitsubishi’s share of Formagrind’s tooling budget rose from 10% to more than 80% of the total spend in just over five years. Because of Formagrind’s evolution from an occasional purchaser of Mitsubishi tools to a consignment stock customer, an Autocrib tool vending system was installed in April.
So when the new order came in, Formagrind naturally turned to Mitsubishi for technical assistance. Managing director Mike Couser explains: “The new order was for over 100 complex titanium fixtures that each consist of a carrier base and corresponding top plates that clamp electronic PCB assemblies during their production and final assembly processes. Firstly, we needed two new VMCs [vertical machining centres] to give us the additional machine capacity; and, secondly, we needed consistent lights-out production. This is when Mitsubishi stepped in with its solid carbide end-mills.”
The base plate and corresponding top plate cover units that clamp the automotive electronic assemblies were initially required in a batch size of 105 bases and 160 cover plates. With over 14 hours of machining for each base and 110 minutes’ machining for each cover plate, Formagrind realised that it needed to run its new VMCs, two Hurco (01494 442222) VMX30Mi machining centres, 24 hours a day, seven days a week for almost two months. As the iMachining Technology Wizard cutting parameter optimisation capability of SolidCAM (01226 241744) was working to improve the process, the key factor in achieving unmanned lights-out production was the cutting tools.
For both base plates and top guide clamps, Formagrind developed both custom fixtures and a cutting sequence using multiple Mitsubishi solid carbide four-flute VQ Series end-mills for cutting features of different sizes. For example, on the base plates it used an 8 mm end-mill at 4.5 mm depth of cut and 1.2 mm step-over at a feed rate of 1,400 mm/min.
This article was originally published in the September 2016 issue of Machinery magazine.