British high-tech company Domin is transforming industries with 3D-printed, high-efficiency hydraulic components, supported by the process-reliable precision of the STUDER S33 universal cylindrical grinding machine.

At the Domin Technology Centre (DTC) outside Bristol, innovation is evident throughout the facility. The bright, organised halls house advanced 3D printing systems, EDM, and milling machines, alongside the recently installed S33 cylindrical grinding machine from STUDER. These tools are operated by a team of 85 highly skilled professionals focused on advancing motion control technologies.

Hydraulics, which uses pressurised fluids to control force and movement, remains critical across applications, from excavators and aircraft landing gear to automotive braking systems. Despite its importance, the field has seen limited innovation since the 1950s.

"Traditional hydraulics is incredibly powerful, but also notoriously inefficient. Conventional systems can waste up to 70 per cent of their input energy," explains Cameron Adams, Manufacturing Engineering Manager, Domin. They aim to achieve this with its core products, extremely responsive servo valves and ultra-compact high-performance pumps. The team have therefore made it their mission to take this key technology for virtually every modern industry into the next era, so that more can be achieved with less.

By leveraging metal 3D printing, the company produces components with complex, flow-optimised internal geometries that are not achievable through conventional subtractive manufacturing. These digitally controlled hydraulic systems can deliver efficiency improvements of up to 90 per cent compared to traditional solutions. For example, a single modern valve from Domin reduces costs by around $400 per year, which leads to significant savings in large systems. The customers are found in industries such as aerospace, automotive and motorsports, industrial manufacturing, robotics, shipping, and energy.

Domin manufactures components using maraging steel, known for its durability and corrosion resistance and hard form, through 3D metal printing. Post-processing involves surface finishing and precise edge matching, where the control edges of valve slides are aligned with valve housing windows to micrometre-level accuracy—critical for performance.

The additive process is followed by post-processing of the surfaces and fine geometries, known as edge matching, where it involves aligning the control edges of the valve slide with the windows of the valve housing with an accuracy of a few micrometers. This alignment is crucial for the overall performance of the valve. 

Previously, this was achieved through wire erosion (EDM), a precise but slow process. As production demand increased, they required a faster yet equally precise solution. After evaluation, the company selected the S33 CNC universal cylindrical grinding machine from STUDER for its ability to ensure high precision and combine multiple machining operations.

The S33 is now used for high-precision grinding of valve spool diameters and control edges in products such as the S4 Pro, S6 Pro, and S10 Pro series. The S6 Pro valve, for example, requires a diameter tolerance of just three micrometres (0.00012 inch), approximately twenty times smaller than a human hair.

“The precision and reliability of the STUDER machine exceeded our expectations. During the acceptance test, deviation across 50 components was only 0.0006 mm (0.000024 inch) due to in-process measurement,” says Adams.

This performance is enabled by advanced grinding technologies and high-quality components developed over more than 113 years of expertise. The S33 incorporates the C.O.R.E. hardware and software architecture, featuring a large touch display for intuitive operation and visualisation of production data. Additional features include frequency-controlled motor grinding spindles for internal and external grinding, and a Granitan S103 mineral cast machine bed that ensures thermal stability and vibration damping.

Overall, the S33 has enabled Domin to raise its production to a higher level. Thanks to the extremely low tolerances, the hydraulics specialists can now produce their valve spools and blocks as fully interchangeable components in series production. The manual pairing of components that was previously necessary is no longer required. For Domin, the decisive technological advantage of the S33 was its configuration with two grinding wheels. "The ability to grind both the diameters and the shoulders of the spools in a single machine is a game changer for us," says Adams, explaining, "We know that if there is a possibility for errors, they are likely to occur at some point. To reduce this risk, we designed the process so that grinding wheel changes or tailstock movements are not necessary. This approach not only reduces setup time, but also minimises the costs typically associated with errors. In addition, the transition from EDM to cylindrical grinding on the S33 for the S6 Pro valve has led to a dramatic improvement in efficiency—machining time has been reduced from nearly an hour to just five minutes.

Domin and STUDER also enjoy a trusting working relationship. "Communication between our specialists and the excellent engineers at Domin worked very well right from the start. Together, we were able to identify the S33 as the optimal machine and configure it for the specific production requirements," recalls Michael Läuffer, Area Sales Manager UK/Ireland and Benelux, STUDER. This advice and mutual trust were key for Domin. "We didn't just get a machine; we got a well-thought-out solution. The technical support and ability to respond to our wishes were first-class and made the entire implementation process much easier," confirms Adams.

Looking to the future, Domin is clearly focused on growth. Production volume is set to increase exponentially in the coming years. To cope with this, the next step has already been decided: automating part loading is the next milestone on the road to highly efficient series production. This is another reason why the S33 with its smart and future-proof automation options was chosen. "With STUDER, we have a partner at our side who will accompany us through these development steps and help us realise our vision of a fully automated, intelligent manufacturing process," summarises Adams.

Domin is focused on scaling production in the coming years, with automation identified as the next milestone. Automated part loading is planned to further enhance efficiency and support high-volume manufacturing. The S33’s standardised interfaces and automation capabilities make it well suited for this transition.

“With STUDER, we have a partner who will support our journey towards a fully automated, intelligent manufacturing process,” concludes Adams.