Newly set up machining centre fits into tight space

The manufacturing facility entrance was the main issue when Mr Dunn was looking to buy a three axis Vertical Machining Centre (VMC), as the door lintel is only 2.2m from the ground.

After researching various options, he identified the perfect machine for his needs. It was the recently introduced Hurco VM5i, which is less than two metres tall with the ram lowered and has a compact footprint of slightly over 1.6x2.2m. It nevertheless has a generous working envelope of 457x 356x356mm.

The BT40 machine, which was installed and commissioned in January 2017, complements existing plant including a floor-standing laser profiler for prototyping and producing jigs and fixtures, a flat-bed CNC lathe with one metre between centres for turning parts up to 300mm diameter, and a machine for 3D printing resin models.

Mr Dunn said: “I could not offer contract machining services during a two year exclusion period after selling my previous company, Drurys Engineering in Hitchin. Now that I am free to re-enter the industry, I have chosen the Hurco VMC for its size and capability.”

Overstone Engineering’s target market is the design, production and assembly of items that invariably disrupt activities on other manufacturers’ shop floors. Typically they include machining of prototypes in ones and twos, small-volume milling and turning and electro-mechanical assembly. Additionally, the company provides advice and an engineering service to designers, entrepreneurs and inventors.

Shortly after the VMC was installed and training had been completed at Hurco’s High Wycombe technical centre in a process described by Mr Dunn as painless, a contract was won for the production of a robotic test rig to be used for non-destructive testing in the aerospace industry. Overstone Engineering assisted in the design, working closely with the customer throughout all stages of the production, which included visits by its staff to the manufacturing facility.

A number of contracts were completed on the VM5i in the first five months of operation, involving materials from nylon and aluminium to phosphor-bronze and steels. The most recent was the production of a single assembly made largely of phosphor bronze for an unspecified application.

A majority of Overstone Engineering's work is programmed directly at the control using Hurco's conversational programming software. In this case, however, it was simpler to export a DXF file from Mr Dunn’s OneCNC CAD package and use the DXF facility in the Hurco control to generate the cutter paths automatically.

Mr Dunn continued, “Besides its compactness, another benefit of the Hurco machine is the high level of technology built into its control software. In addition to having the option of a module that allows native handling of DXF files, it can accept externally written G-code for milling 3D freeform surfaces.

“Ultimotion software was supplied as part of the package, giving fast, smooth, dynamic motion that is exceptional for such a low cost machine and greatly helps to reduce cycle times and improve surface finish.” Throughout his career, Mr Dunn has accumulated a vast amount of engineering knowledge and experience in the aerospace, oil and gas, Formula 1 and security sectors in particular, to which his latest facility is well suited. He also has a long list of contacts in manufacturing companies from sole traders to multinationals and in the material supply chains. He is utilising many of these associates in his current enterprise.

He concluded: “Many in my position would have retired early, but I missed production engineering. So I have decided to go back into subcontracting full-time and if it works as planned, I will offer an apprenticeship to an aspiring engineer so that I can pass on my knowledge.”