DMG Mori publishes case study of ultra-precision CNC milling

DMG Mori, the world leader in precision CNC milling and turning machine tools, published a case study with Vert Rotors. In this story Vert explains how they achieved superior precision of 5μm and high speed of manufacture of Conical Screws, with latest 5-axis CNC milling centre HSC-20 from DMG Mori.

Read: “Green compressors made reality with the HSC 20 linear from DMG MORI” (opens a new window).

Olly Dmitriev, CEO of Vert Rotors, says,“Until recently all micro compressors capable of producing pressures over 2 -3 bar were piston compressors, which produce a lot of vibration. Our rotary design is virtually vibration free, which is vital where the compressor is located next to delicate sensors. Example applications where there is a need for a vibration free compressor include satellites or medical devices. Our new 100W desktop compressor “VERT.04” produces pressure of 8 bar without vibration, and uses small, high accuracy rotors which need to be machined in 5-axis. We looked at a variety of machines and chose the HSC 20 linear. The machine has linear drives and scales unaffected by backlash and the composite granite frame gives exceptional temperature stability making it possible to achieve 5 μm accuracy and very high quality surface finish of Ra 0.15 µm.

Vert Rotors Conical Screw

CMM report for Inner Conical Screw

DMG MORI collaborated with Vert Rotors in the development of the machining strategies, reducing machining times from 4 hours to 1 hour. The machining of the helical surfaces is very challenging and uses 1 mm and 3 mm diameter tools and custom lollipop cutters operating at 30,000 rpm.

James Mackie, Production Engineer, Vert Rotors, machining a Conical Screw


Vert Rotors has only had the HSC 20 linear since the end of December 2016 and is continually fine tuning the machining process. Olly Dmitriev says, “We are getting CMM reports which show consistency between each side of the rotors and we are building our expertise on the machine all the time. We were confident with the machine from day one.”

Steve Finn, Managing Director of DMG MORI UK says, “This is the first HSC 20 linear to be installed in the UK and we are delighted to be involved in the development of Vert Rotors’ green compressor technology. We are working in partnership with them to develop local expertise in the UK for this level of high precision machining. Olly Dmitriev adds, “We are keen to build our knowledge and share our skill on this machine with other companies as it can only be good for UK industry. We have made some huge steps forward in just a few weeks which demonstrates the potential of the HSC 20 linear.”

Credit: DMG Mori