Vert Rotors based in Edinburgh has just won the ‘Innovator of the Year’ title in the ‘Made in Scotland’ awards, making it the best of the best, for its innovative, patented conical screw compressors.

At the heart of the compressor are male and female conical screws which are manufactured to very tight tolerances. The new Vert Rotors Nautilus product packages this technology with the necessary motor, pipework and electronics to produce a plug and play desktop unit, designed for the future of disruptive technology and which is much quieter, more efficient, smaller and lighter than existing technology.

Keigh Ridgeway, Executive Dean of the AMRC Group, presenting the Made in Scotland Award to Olly Dmitriev, CEO of Vert Rotors

The Made in Scotland awards are sponsored by the University of Strathclyde and the Advanced Forming Research Centre (AFRC) and they recognise excellence in innovation, manufacture and the best new products developed in Scotland. The Innovator of the Year award recognises the most outstanding entry of all the winners of the different categories, making it a highly prestigious achievement for Vert Rotors.

The company now has two DMG MORI machines, the HSC 20 linear 5-axis machine and a CLX 350 universal turning centre with sub spindle and Y-axis. The CLX 350 was added primarily to manufacture the casing for the Nautilus compressor which includes drilled and tapped features. However, the HSC 20 linear provides the essential technology required for producing the conical helix parts. Olly Dmitriev, Managing Director of Vert Rotors says, “There are three factors involved in achieving the accuracy we need for the helix – the machine tool, the tooling and the CAM programme. We need to optimise all three for best results. To make this process even more complex, if we change one variable the others are affected, leading us to a holistic approach to solving the problem. Six months ago, we were achieving ±10µ while now we are achieving sub ±5µ despite having changed the material of the parts from brass to 4140 alloy steel which is much harder to machine. The key factors that help us to achieve such accuracy with the HSC 20 linear are the linear drives and its 40,000 rpm spindle speed. This machine allows us to manufacture with 100% repeatability and zero scrap and move on from the development phase to production and shipping of products to customers. Now we can minimise the quality sampling necessary to check that tolerances are achieved and we can also look at unmanned machining out of hours to expand our manufacturing capacity.” The iterative manufacturing development process involved testing many different cutting methods and customised tools with different coatings and took around 12 months to achieve. “Our compressor technology is patented and the manufacturing process will be difficult to replicate, so we are a long way ahead of our competitors. We chose to manufacture the parts ourselves as subcontractors would find it difficult to achieve what we have and, the whole design and development process would have been slowed down considerably. In that respect, DMG MORI has been a key partner in applying the technology.”

Conical screw compressor CRC8 – Conical screw compressor components

Having achieved the 5µ tolerance Vert Rotors saw energy efficiency of the compressor increase by a further 11%. The Nautilus is already 55% more efficient than conventional scroll compressors. Olly Dmitriev explains, “We can produce 21bar from a single stage compressor compared with 7bar for conventional compressors. In addition the air is class 1 purity. The Nautilus weighs just 35kg and we are investigating ways of reducing this to 21kg. Noise is a major factor for compressors the Nautilus can be used in an office environment due to its low noise level. It is clear that high value manufacturing will change with disruptive technology and that much of it is likely to move to smaller specialised locations where a massive compressor is unnecessary and impractical. Already we are seeing demands for our equipment for air bearings in CMMs and in 3D printing as well as defence and space applications where size, air purity, weight, low vibration, low energy consumption and noise are important factors. Essentially, the Nautilus is designed to meet the needs of trends for future manufacturing methods and locations, which are already becoming a reality with 30% yearly increases in the uptake of 3D printing technology. What we have achieved has been made possible following our partnership with DMG MORI. The company is highly professional, open to collaboration and the results we have achieved together are a source of pride. The Innovator of the Year, Made in Scotland award shows what can be attained with inspirational ideas, dedication and technology partnerships.”

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