CNC Milling of a Large Welded Structure on the Matec 40P
For this project, we machined a welded structure measuring 6,000 × 2,000 × 500 mm and weighing approximately 5,000 kg on our Matec 40P. A short lead time was a key requirement for this project.
During machining, the pads were precisely leveled and threaded. These precision machining operations require high dimensional accuracy and a high-quality finish. Thanks to the stability and capacity of the Matec 40P, these operations could be carried out efficiently and with high precision.
MATEC 40P
The large machine bed of the Matec 40P allows multiple workpieces to be clamped simultaneously. This enables us to make optimal use of our production capacity and to efficiently schedule projects with short lead times.
Specialist in Large and Heavy Welded Structures
De Rooy has extensive experience in the metalworking of large workpieces. We specialize in grinding, milling, and measuring large and heavy welded structures up to dimensions of 16,000 × 4,600 × 2,850 mm. With our advanced machinery, we provide high-quality precision machining services for a wide range of sectors within the manufacturing industry.
Our expertise covers components such as drive shafts, hydraulic rods, plungers, rollers, and cylindrical parts for machine building and industrial systems. Solid shafts, tubes, and hollow shafts can all be processed with the same focus on accuracy and surface quality.
> Project in the spotlight: Grinding large shafts
> The Danobat G91 CNC Grinding Machine
> Grinding Capacity for Shafts at De Rooy
Project in the spotlight: Grinding large shafts.
A recent project involved the grinding of a heavy-duty shaft.
Component specifications:
- Diameter: 250 mm
- Length: 3.000 mm
- Weight: 1.050 kg
- Surface to be ground: the entire roller surface and the shaft
Despite the size and weight of the component, tight tolerances were required to ensure proper sealing, alignment, and reliable operation in the final machine.
The Danobat G91 CNC Grinding Machine
For this project, we used our Danobat G91-S CNC cylindrical grinding machine, specifically selected for large and heavy shafts.
Danobat G91 capabilities:
- Maximum grinding dimensions: Ø 1000 mm × 4000 mm
- Maximum workpiece weight: 5,000 kg
- External cylindrical grinding
- Conical grinding
- Profile grinding (where required)
This machine allows us to combine size, stiffness, and precision—essential for consistent results on long shafts with large diameters.
Grinding Capacity for Shafts at De Rooy
In addition to the Danobat G91, our grinding department includes several other CNC grinding machines, allowing us to handle a broad range of shaft dimensions:
- Ø 670 × 3000 mm – AMC-Schou R3000
- Ø 550 × 1500 mm – WMW-Heckert
- Ø 500 × 2000 mm – Fermat BUB E50/2000 CNC
- Smaller machines up to Ø 350 mm × 1000–1500 mm
Applications and Industries
The shafts and cylindrical components we grind are commonly used in:
- Machine tools and rotating assemblies
- Pumps and mechanical systems
- Hydraulic and mechanical plungers
- Offshore and mining equipment
- Heavy industrial machinery
- High-tech machine building
- Semiconductor, food, and process industries where tight tolerances are essential
The combination of large dimensions and high precision makes De Rooy a reliable partner for both traditional and advanced industrial sectors.
Fast Lead Times and Flexibility
Speed is often just as important as accuracy. De Rooy is known for its flexibility and short lead times, even for heavy and complex components. Whether it’s a planned production order or a time-critical rush job, our team is equipped to respond quickly and deliver consistent quality.
Looking for Precision Grinding of Large Shafts?
If you require accurate grinding of long or large-diameter shafts with fast delivery and dependable quality, De Rooy is ready to support your project.
Caroline: “You don’t need to be technically minded. You just need to be willing to learn.”
Caroline (61) has now been working at De Rooy in the tool centre for four years – quite a career change from the catering and logistics sectors.
“I wanted to do something with my hands. Not sit in front of a computer all day. Just keep busy, make something tangible and see what you’ve achieved at the end of the day.”
From the catering industry to a new challenge
“I ran my own restaurant business for fifteen years. It was hard work, but I felt it was my calling. You’re constantly interacting with people, switching gears all day long, and no two moments are ever the same.”
After that, she worked in a hospital warehouse.
“It was all about organization, logistics, and responsibility. Making sure everything arrived on time and in the right place was rewarding. Still, I hit a wall; despite good performance reviews, I didn’t get a permanent contract. That didn’t feel right.”
Through an acquaintance, she got in touch with De Rooy.
“I didn’t know much about engineering, but I did know that I wanted to do hands-on work. To learn something new. And here, I got that chance.”
What does a tool manager do at De Rooy?
At the tool center, Caroline is responsible for assembling, calibrating, and managing tools for various machines.
“Every day, we receive tool lists for production orders. Based on those lists, I assemble the tools, measure everything precisely, and enter the data into the system. Only when everything is correct does it go to the machines.”
The work requires precision.
“A small measurement error can have major consequences. At first, I made a mistake when taking measurements. That was an expensive lesson, but it’s all part of learning.”
She emphasizes: “Technology is much more than just a machine that does the work. Without well-designed tools, nothing here works. It’s a team effort between programmers, milling machine operators, and the tooling center.”
From Speed to Precision
“In the restaurant business, everything has to happen fast. Here at De Rooy, I learned that it’s all about precision, not speed. My coworker would always say, ‘Take your time—it has to be done right, not fast.’ That was really a big adjustment..”
Caroline took her learning process seriously.
“I took pictures of tools, wrote everything down, and studied the subject in depth at home as well. If you’re curious and willing to learn, you can master this trade.”
What pleasantly surprised her was the guidance she received.
“I was regularly invited to talk: How are you doing? What do you think? I’d never experienced that before. That attention gave me confidence.”
Flexibility and Trust at De Rooy
Caroline first worked 32 hours a week, then full-time, and now works under the intergenerational pact.
“At De Rooy, you’re given that flexibility. They really work with you to find what fits your situation.”
According to her, De Rooy’s strength also lies in the little things.
“A small gift sent to your home, monthly cake, moments of relaxation at work, staff parties. They may be small details, but they show that employees are valued.”
Engineering has no standard profile
At De Rooy, 20 of our 125 colleagues are now women. The technical sector is also a great place for women to learn, grow, and further develop their careers.
“The atmosphere is good. Everyone is willing to help. Our Tool Center is now staffed by three women.”
Especially for women who are unsure:
“You don’t need to have a technical background. If you can work accurately and are interested in technology, you can learn it. Perhaps women are actually particularly well-suited to this work, because accuracy is so important here.”
She laughs:
“And yes, sometimes you get a bit dirty. Luckily, that’s what gloves are for.”
Two seconds of courage
Many of the people she speaks to are unsure about switching to a technical career.
“Ze zitten al jaren bij hetzelfde bedrijf. Niet altijd gelukkig, maar durven de stap niet te zetten.”
Her advice:
“Come and spend a day with us at De Rooy. You’ll get a feel straight away for whether the company’s right for you. Sometimes all it takes is 20 seconds of courage to change your life.”
She herself has never regretted it for a moment.
“It’s a responsible job, challenging, and I’m still learning something new every day. That keeps me on my toes.”
Broadening one’s horizons
“I would advise everyone to keep developing themselves, not least to broaden their horizons. The possibilities are endless.”
Are you ready for a career change? At De Rooy, we warmly welcome people changing careers! Click here to view our vacancies. Or would you like to speak to our HR colleagues Mary or Dana about the opportunities? Please call us on: +31 (0)40 – 281 34 59.”
The integrated measuring arm monitors dimensions during the grinding process, ensuring consistent quality and repeatable results.
Our Kehren machines are suitable for complex precision grinding operations in both single-part and series production.
> Advantages of Kehren RI Machines
> Technical information about the Kehren RI 12-4
Advantages of Kehren RI Machines
- Cylindrical and surface grinding in a single setup
- High dimensional accuracy and repeatable quality
- Suitable for large and heavy workpieces
- Integrated in-process measurement control
- Flexible deployment for small and large production runs
Technical information about the Kehren RI 12-4
Capacity: Ø1500 x 950 mm
Operations:
- Vertical grinding
- Internal cylindrical grinding
- External cylindrical grinding
- Coordinate grinding
Technical information about the Kehren RI 8-4
Capaciteit: Ø1200 x 700 mm
Operations:
- Vertical grinding
- Internal cylindrical grinding
- External cylindrical grinding
- Coordinate grinding
- Hard turning
Specialist in Precision Grinding
We combine craftsmanship, controlled processes and advanced grinding technology for cylindrical grinding, surface grinding and the machining of large industrial components.
With the Kehren RI 8-4 and RI 12-4, we deliver consistent quality for applications where accuracy, dimensional stability and reliability are essential.
Interested in the possibilities for precision cylindrical and surface grinding? Feel free to contact us.
> From the Legal World to Entrepreneurship
> Building Growth Together
> Strategic Decisions That Made a Difference
> The Power of Entrepreneurship in a Family Business
> Letting Go and Making Room for Personal Growth
> What Marc Takes Away from His Time at De Rooy
> A New Chapter
From the Legal World to Entrepreneurship
Interestingly, his career didn’t begin in the metal industry, but in the legal world. After earning his law degree, Marc worked for several years as a lawyer at various organizations, but he felt something was missing, something tangible.
“In the legal world, I missed the direct impact of my work. You give advice, draft documents, and conduct analyses, but the results often remain abstract. I wanted to build things. Make decisions. Be an entrepreneur.”
The family business continued to draw him in, not out of a sense of obligation, but out of conviction.
“At De Rooy, I could do everything: from finance and process improvement to contributing ideas on strategy. You’re involved in everything and see immediately what your efforts yield. That tangibility, that sense of building something together, really appealed to me.”
Building Growth Together
In 1992, he joined the family business. His role as a member of the executive board was wide-ranging and, at times, unexpectedly hands-on.
“For a lawyer, it was an unusual move. From administration and finance to shipping; sometimes I even hopped on a forklift. It was precisely that versatility that made entrepreneurship so interesting.”
During his years at De Rooy, Marc grew alongside the company. What had been a small metalworking business with about twelve employees on Hofstraat in Eindhoven in 1992 evolved in the years that followed into a professional organization offering a broader range of services on a larger scale.
One of the most defining moments was the move in 2007 from Hofstraat in Eindhoven to Collseweg in Nuenen.
“We had outgrown our space on Hofstraat. The new building also meant a hefty mortgage. When the market crashed in 2008, that decision was immediately put to the test. If the economy had slumped even further, we would have faced a serious problem. That really kept me up at night. Fortunately, we were able to lease part of the building and the outdoor area to Kuhn. That ultimately turned out to be a win-win situation.”
It’s precisely in moments like these that entrepreneurship shines through: taking risks, making adjustments, and finding solutions together.
Celebrating milestones was also part of the journey. In 2010, De Rooy was named Entrepreneur of the Year by the Nuenen Entrepreneurs’ Association.
“That was a particularly meaningful moment, not just for me personally, but for the entire executive team. It confirmed that our presence in Nuenen was genuinely appreciated. Our dedication and the choices we made were noticed and recognized, even by the local community.”
Strategic decisions that made a difference
In addition to securing facilities, strategically important decisions were also made. One of these was the decision to start milling in 2011, in addition to grinding.
“We were outsourcing more and more milling work. At some point, you have to ask yourself: why don’t we do it ourselves? That turned out to be a game-changer.”
A clear course was also set in the area of quality. The purchase of a large measuring machine made unique measurement reports possible and led to a significant increase in professionalism.
“That gave us a huge boost in quality. It elevated us to a higher level in terms of reliability and reputation.”
The Power of Entrepreneurship in a Family Business
Still, his story isn’t just about more machines or square meters, but also about having, and maintaining, a sense of care for one another.
“When you work in a family business, work and personal life are always intertwined. You’re not just colleagues, you’re also family. That makes it special, but sometimes also complex. That intertwining requires care: in decision-making, in communication, and in our relationships with one another. I look back with pride on the fact that we took those steps together as a team.”
Marc emphasizes the unique aspects of entrepreneurship within a family business:
“The lines of communication are short, and decisions are made quickly. But more importantly, you think in terms of generations, not quarters. You take each other into account, as well as relationships and the future of both the company and the family.”
That sense of connection makes a family business strong, but it also places responsibility on everyone’s shoulders.
“Every role within the company is important. You do it together. That’s the mindset, and you can feel it in the company culture. That sense of commitment makes all the difference, but it also means that choices sometimes carry more weight.”
Letting Go and Making Room for Personal Growth
After more than twenty years, Marc realized he wanted to take a different approach to his entrepreneurship.
“I felt the need for space, space to chart my own course, explore new ideas, and start over.”
The process of stepping back was gradual.
“You talk a lot. You reflect. You look ahead. It’s a collaborative process in which you have to be generous with each other. The most important thing was to maintain good relationships. A business is important, but so is family.”
What Marc Takes Away from His Time at De Rooy
The years he spent at the family business shaped Marc as an entrepreneur.
“You learn to take responsibility, not just for results, but for people, for continuity, and for decisions that have repercussions for years to come. You learn that growth isn’t just about getting bigger, but about getting better.”
A New Chapter
Marc is fully focused on his own entrepreneurial endeavors through Jorhan Consult B.V., a company active in management, mediation, and administration. On his LinkedIn profile, Marc de Rooy | LinkedIn, you can clearly see how diverse his work is: from consulting and strategy to administration and involvement in various projects.
“It doesn’t feel like leaving something behind, but rather like taking something with me into a new phase. Everything I learned at De Rooy, I now use every day in my work. Of course, it’s exciting, but entrepreneurship is also about having the courage to take action when the time is right.”
With respect for the past and energy for the future, Marc is consciously choosing his own path.
“Sometimes you have to step away from something that’s good to make room for something that suits you better. My motivation now is to help projects and businesses grow further, to build connections, and to achieve results, both for the people involved and for the organization. It’s always important to keep the business healthy and the family happy.”
With these machines, De Rooy Grinding Centre specialises in precision surface grinding for small and large series. Thanks to the advanced machine construction, we deliver consistent and reproducible grinding quality, even for large and complex workpieces.
> High accuracy and reproducible quality
> Efficient-surface-and-profile grinding
High accuracy and reproducible quality
Okamoto CNC CHiQ machines are designed for industrial precision grinding operations where dimensional accuracy and low surface roughness are crucial. The rigid machine construction and high-quality guides minimise vibration, resulting in:
- very high dimensional accuracy
- low surface roughness
- stable and consistent grinding results
This makes our grinding operations ideal for applications where precision surface grinding is essential.
Efficient surface and profile grinding
Our machines are equipped with intuitive and user-friendly controls similar to those of our other Okamoto surface and profile grinding machines. This ensures a high degree of process reliability and uniformity within our industrial grinding centre. Multiple machines can be deployed flexibly, enabling us to scale up efficiently and guarantee reliable delivery times.
Large capacity for long and heavy workpieces
With grinding lengths of 2 meters, 2.5 meters and 3.5 meters, our Okamoto CHiQ machinery has an exceptionally large capacity. This means we are ideally equipped for:
- surface grinding of large workpieces
- surface grinding of long workpieces up to 3.5 meters
- small and large series
- precise grinding of complex components
Specialist in industrial surface grinding
Whether it concerns dimensionally stable grinding, precision grinding or machining long components we combine high-quality Okamoto surface grinding machines with craftsmanship and process control. This enables us to deliver consistent quality that meets the highest industrial requirements.
Curious about our surface and profile grinding machines or precision surface grinding options? Feel free to contact us.
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At De Rooy in Nuenen, we specialize in machining heavy welded frames and cast structures for OEMs across these sectors. Our unique combination of large-scale machining capacity and high accuracy makes us a trusted partner for components that most suppliers simply cannot handle.
> Supporting Europe’s Traditional Industries
Heavy Frames, High Accuracy
Many of the frames we process weigh tens of thousands of kilograms and require machining across all sides. A typical example is a construction measuring 5,000 × 2,700 × 2,000 mm and weighing 23,000 kg, a size and weight that only a small number of machining suppliers in Europe can accommodate.
Welded or cast, these structures often come with their own challenges:
- Heat distortion
- Internal stress
- Geometric deviations
- Large, uneven surfaces
Correcting these issues with precision demands not only powerful machinery but also extensive expertise in handling complex heavy structures. De Rooy offers:
🔹 Large-capacity CNC machining for multi-ton frames in oversized dimensions
🔹 Specialists in welded and thick-walled constructions
🔹 Advanced fixturing and in-process measuring for accuracy over large distances
🔹 Stable, repeatable processes suited for both single pieces and recurring production
Supporting Europe’s Traditional Industries
Our machining services support OEMs in:
- Heavy agricultural machinery
- Mining and earth-moving equipment
- Offshore and marine systems
- Shipbuilding infrastructure
- Metal production and processing equipment
- Chemical and process industry machinery
In these sectors, durability is essential, but precision is too. Even small dimensional deviations in a 20-ton frame can lead to assembly issues, increased wear, or reduced system efficiency.
Our ability to machine extremely heavy frames to tight tolerances ensures these components integrate seamlessly into your final equipment.
Why a European Machining Partner Matters
For traditional industries, choosing a European supplier like De Rooy provides major advantages:
🔹 Lower Logistics and Shipping Costs
Transporting a 23,000-kg frame across continents is costly and complex. European production significantly reduces shipping time and expense.
🔹 Faster and More Flexible Delivery
Shorter supply chains mean quicker adjustments, faster lead times, and smooth handling of design changes.
🔹 Direct Communication and On-Site Collaboration
Engineers can visit, inspect, and collaborate easily improving quality and reducing project risk.
🔹 Reduced Risk in Complex Projects
Local machining eliminates long transit risks, customs delays, and logistical uncertainty.
Built for Heavy-Duty Machining Needs
Our facilities, equipment, and team are specifically equipped to handle oversized industrial frames that few suppliers worldwide can machine. Whether it’s a 23-ton welded frame for mining equipment or a large base structure for chemical processing machinery, we deliver precision, consistency, and reliability. De Rooy is ready to support traditional industries with dependable machining of large, heavy, and complex structures delivered with the accuracy your machinery demands.
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> Working in the CAD/CAM department: no two days are the same
> Working on complex CNC projects
> CNC programming: Technology and creativity
> Collaborating within CAD/CAM and production
> Developing your CNC knowledge and CAD/CAM programming skills and continuing to grow in these areas
> Taking pride in complex CNC projects
> Working at De Rooy in the CAD/CAM department
> Ready for the BIG precision work?
Working in the CAD/CAM department: no two days are the same
Within the CAD/CAM department, multiple disciplines work closely together. The CAD/CAM programmers convert technical drawings into CNC programs that control the machines. These are digital instructions that describe, step by step, how a part is machined: which tools are used and which operations are required.
In addition, colleagues from Proxia and the tooling department play an important role. Proxia is the central platform where De Rooy brings together various digital processes. This system was deliberately chosen because it provides greater clarity, efficiency, and a standardized way of working.
Among other things, the Proxia team manages part and tool inventory, ensuring that everyone has access to up-to-date and reliable information. The tooling department then ensures that tools are built according to specifications and are available in a timely manner for production.
From a digital perspective, De Rooy is already well advanced. Many processes are fully digital and are supported daily by Proxia, which provides greater insight, control, and efficiency within the production process.
According to Tim, it is precisely this collaboration between CAD/CAM, Proxia, and tooling that is essential for the successful execution of complex projects.
“We make sure everything is correct before it goes to production. That requires precision, insight, and close collaboration within the team.”
The parts you work on are large and complex.
“Think of projects for sectors such as semiconductors, mining, and the food industry. Parts up to 16,000 mm in size, with high precision down to the micron level.”
It’s precisely that combination that makes the work challenging.
“The best part is when a complex project is spot-on down to the last detail. When you create a (final) product you can truly be proud of.”
Working on complex CNC projects
At De Rooy, you don’t work on standard or simple projects, but on complex, custom CNC machining jobs.
“Every project starts with a kick-off meeting. Then, together, you determine the strategy: how will you make the part, what clamping method will you use, and what tools do you need?”
Sometimes that takes a few days; sometimes several weeks.
“That’s exactly what makes the work interesting. You get the time to really refine a CNC program and optimize the process.”
CNC Programming: Technology and Creativity
The job requires more than just technical knowledge.
“You’re constantly optimizing. What’s the smartest approach? How can you make the process more efficient? That’s what makes the work challenging.”
You’ll also be working with professional CAD/CAM software such as Hypermill.
“But ultimately, the difference lies in the thought process and the choices you make along the way.”
Collaborating within CAD/CAM and production
Within the CAD/CAM department, you’ll work alongside experienced programmers and colleagues in training. Sharing knowledge is key.
“We help each other, share our experience, and are constantly learning. That’s what makes the team strong.”
Collaboration with other departments, including production, work planning, and quality control, is also important.
“From CNC programming to final inspection: you really do it together.”
What sets De Rooy apart:
“Programming is done centrally. This allows us to maintain an overview and prevent errors in production.”
Developing your CNC knowledge and CAD/CAM programming skills and continuing to grow in these areas
Trainees are trained step by step in CAD/CAM programming. If you want to advance internally to become a CAD/CAM programmer, you must have worked as a miller at De Rooy for at least 2 years. Are you applying directly for the position? Then at least 2 years of experience with HyperMill is required.
“You’ll start with smaller CNC parts and work your way up to more complex projects. You’ll receive guidance, but you’ll also be given responsibility.”
According to Tim, the right attitude is important.
“If you’re curious, work with precision, and show initiative, you can grow quickly at De Rooy.”
Taking pride in complex CNC projects
The work produces tangible results, and that makes me proud.
“One project that will always stick with me is a 20-metric-ton piece of aluminum that was ultimately reduced to 4.3 metric tons. Projects like that show what we’re capable of as a team in CNC machining.”
Working at De Rooy in the CAD/CAM Department
Working at De Rooy means working on technology that makes a difference, in an environment where you continue to learn about CNC and CAD/CAM programming.
“Here, you’ll have the opportunity to develop yourself, collaborate with skilled colleagues, and make a real impact on the production of complex parts.”
For anyone who loves technology, CNC, and CAD/CAM programming, the choice is clear, according to Tim:
“If you get energized by complex challenges and creating technical solutions together, you’ll quickly feel at home here.”
Ready for some BIG precision work?
Our modern, expanding fleet of machinery is ready for any challenge, and we are looking for a CAD/CAM programmer who has an eye for detail and isn’t afraid to take on BIG projects.
LARGE SCALE. precision craftsmanship.
These 12-meter-long beams are milled with the highest precision. Components of this size demand specialist knowledge and advanced machine capabilities, where craftsmanship makes all the difference.
This marks the start of a new collaboration, defining together with Van Halteren Technologies Boxtel how products are optimally manufactured and treated, including machining operations and post-processing such as galvanizing.
The work is carried out on the Uni 16, the longest milling machine in this hall, featuring a 16-meter clamping table. This machine can handle components up to 16,000 × 4,000 × 1,300 mm and allows multiple setups to remain in place simultaneously, ensuring long and heavy workpieces are machined efficiently and accurately.
- Beam dimension: 12,000 x 130 x 120 mm
- Weight: ca. 1,500 kg
Curious about our CNC milling machines? Check:
De Rooy was founded in 1939 and has approximately 125 employees. The company started as a grinding shop for industrial knives and grew into a specialist in large-scale and precision grinding, milling, and measurement. “Our slogan is ‘BIG on precision,’” says Adam (on the left in the photo). Within the family business, Adam De Rooy represents the third generation, while Frans (on the right in the photo) and Floortje de Rooy represent the fourth generation. Together, they ensure the continuity of De Rooy. After decades in Eindhoven, the company moved to Nuenen in 2006. Since then, the complex has been expanded several times, including the addition of a large measuring room (2012), a hall extension for a grinding machine (2015), and a new production hall in 2020 for large-scale milling work. “When we built that facility, we already factored in the need for multiple large gantry milling machines,” says Adam. “The plan was to install a new one every few years.” With the second PAMA, the third milling machine in the hall, the space is now largely filled.
Solid foundation
The new PAMA Vertiram is one of the largest portal milling machines in the Netherlands. Its foundation is exceptionally heavy-duty. “There are 36 nine-meter piles underneath and about 500 cubic meters of concrete,” Adam explains. “The manufacturer tests the foundation by placing a 50-metric-ton weight on it. Afterward, it’s allowed to move by a maximum of four micrometers. If it moves more than that, they reject it, but ours passed.” The machine was ordered in 2023 from PAMA in Rovereto, Italy. Installation has since been completed, and the first machining job is done: a nearly 44-metric-ton cylinder made of tool steel for high-tech machine building. The Vertiram is equipped with four spindle heads: one high-speed head and three low-speed heads. The tool magazine can hold 384 tools, more than double the capacity of the first PAMA (180). The chip conveyors have also been expanded to better handle the large volumes of aluminum chips. “The first machine has a chain changer, while this one has a robotic system,” says Frans de Rooy. “That works faster and more reliably. We keep the machines as versatile as possible so that we can machine both aluminum and steel.”
Large and precise
De Rooy specializes in large and precision workpieces. Its largest grinding machine can process parts up to 8 x 3 x 1.5 meters. The largest milling machine, the PAMA, can handle workpieces measuring 14 x 4.6 x 2.8 meters with a maximum weight of 50 metric tons. Some products arrive as semi-finished goods and are sent on to De Rooy for further machining. “The best part is when we can combine milling, grinding, and measuring,” says Adam. “A workpiece that needs to be milled, ground, and measured is a perfect fit for us. That’s when we make the most of our strengths.” They complement each other nicely. Milling is faster, but grinding allows you to achieve tolerances that aren’t possible with milling. The ratio of milling to grinding at De Rooy is about fifty-fifty. All the production halls are fully climate-controlled at 20 degrees Celsius. “That’s crucial,” Adam explains. “We have machine beds measuring four to five meters that must be flat to within five micrometers. That’s not possible without a stable temperature. Large workpieces also need to acclimate first before we start machining them.” ’The company serves clients in the semiconductor industry, mechanical engineering, the food industry, offshore, and mining, among others. About twenty percent of its customers are located abroad. ‘We deliver to Germany, Belgium, France, and even Switzerland,’ says Adam. ‘When it comes to large-scale grinding work, they know exactly where to find us.’
Automation in Practice
De Rooy operates on a two-shift system and produces over 100 hours per week. Many workpieces have long cycle times, ranging from a few hours to eighty hours. That calls for smart scheduling. Frans: “We schedule the longer cycles in the evening and at night, so the machines can continue working autonomously. The PAMAs have two pallets. Machining takes place on one, while the other is loaded outside. This allows us to reduce setup time.” Programming is done entirely offline using Hypermill. Six programmers handle all the milling programs. “All machines run on Heidenhain controls,” says Adam. “That makes the milling machines highly versatile.”
Digitization
Digitization is a key priority. The milling and cylindrical grinding departments are now paperless, and the grinding department will follow in 2026. The administrative processes have also been largely automated. “Orders and work orders are automatically generated and verified,” says Frans. “The employee’s role is increasingly shifting toward monitoring what the software does.” He is cautiously optimistic about AI programming. “It’s coming quickly for small jobs, but not yet for large ones. There are too many variables involved there. We do create macros to automate repetitive tasks.”
Sustainable Production
In addition to precision, De Rooy invests in energy efficiency and sustainability. There are 4,200 solar panels on the roof, which account for approximately 40 percent of the company’s own energy consumption. “Since we operate 100 hours a week, we use that electricity off the grid,” says Adam. The company is ISO 14001-certified and has replaced older machines with more energy-efficient models in recent years. The six Unisign machines are being equipped with an eco-mode designed to further reduce energy consumption. A striking example of a sustainable investment is the purchase of the briquetting system for aluminum shavings. “When we started milling a lot of aluminum, the bins would fill up in ten minutes,” Adam explains. “With the briquetting machine, we compress the shavings, reducing their volume by a factor of eight, and extract the coolant, which we reuse. Plus, the briquettes yield a higher return during recycling.”
Training Skilled Workers
Finding skilled workers remains a challenge. “There’s no proper training program for grinding,” says Adam. “We train people in-house. Often, they’re young men who’ve worked in other fields but still want to learn a technical trade. We turn handy people into grinders or millers.” De Rooy has three HR staff members, one of whom focuses entirely on recruitment. New employees sometimes start through a staffing agency but are later hired on a permanent basis. “We want everyone to be on a permanent contract,” says Adam. The workforce is relatively young. “We’ve grown rapidly in a short period of time, so the average age is low,” he says.
Ready for the Future
With the second PAMA Vertiram and a new Unisign machine currently under construction, De Rooy will have sufficient capacity for the coming years. “We invested in 2023 when the market was booming,” says Adam. “Things are a bit slower now, but when the market picks up again, we’ll be ready to move forward.” In the coming period, the company plans to modernize its machining fleet, complete its digital transformation, and possibly expand.
“The machines we’re installing now will still be milling here in 25 years,” says Frans. “We buy for the long term. Machines often get bigger as they need to handle more capacity. Machines won’t become less precise or simpler in the coming years. Everything is getting more complex. And as it gets more complex, it automatically becomes more precise,” he concludes.
Machine List
Want to learn more about our machines and capacity?
Text: Kasper Weigrand
