CNC machining in practice – SIM Gdynia in the TVP3 Gdańsk programme “Zawodowcy”
On a daily basis, we focus on stable processes, quality and timely production. This time, however, we had the opportunity to take a break from our daily work routine and look at our CNC machining from a slightly different perspective – that of a television camera. We had the pleasure of participating in the Zawodowcy programme, broadcast on TVP3 Gdańsk. The programme crew visited our plant to show what modern mechanical component production looks like in practice – from the technological background to the daily work of the team. CNC production “from the inside” CNC machining is often associated exclusively with machines and automation. However, the reality of production is much more complex. During the recording, we were able to present the entire process of manufacturing parts – from technology preparation, through tool and parameter selection, to quality control. The camera accompanied us on the production floor, where we carry out turning, milling and more complex multi-axis operations. We showed how important process stability, repeatability of operations and operator experience are, especially in series production and for parts with high quality requirements. The people behind the technology One of the important elements of the episode was the presentation of the daily work of CNC technicians and operators. Modern machinery is essential, but without a competent team, predictable and safe production is impossible. The material clearly shows that CNC machining is a team effort – requiring precision, responsibility and continuous process control. These are the aspects we tried to show the viewers of the “Zawodowcy” programme. We encourage you to watch the episode The episode featuring SIM Gdynia is available online. We encourage you to watch the material and take a look behind the scenes of our daily work: https://gdansk.tvp.pl/90312497/odc-01122025-technik-mechanik We would like to thank the TVP3 Gdańsk team for their visit and the opportunity to show what modern CNC machining looks like in practice at SIM Gdynia.
Serial production in CNC machining – how to reduce costs without compromising quality
Serial production in CNC machining very quickly verifies all technological decisions. What works acceptably in a short series or prototype begins to generate real costs in a long production cycle: shortages, corrections, downtime and accelerated tool wear. Therefore, reducing costs in serial production is not simply a matter of increasing parameters or shortening cycle times, but of consciously designing a stable process. In practice, the cheapest part is not the one made the fastest, but the one that is produced repeatedly – without quality surprises and unplanned interventions during the series. Serial production in CNC machining as a system of interrelated technological decisions Serial production is a system in which each decision affects subsequent stages: from the selection of semi-finished products, through the machining strategy, to quality control. The larger the scale of production, the more pronounced the effects of even minor errors at the planning stage. Production scale and process variability As the number of parts increases, the importance of process variability increases. Minimal differences in tool wear, temperature or clamping rigidity begin to accumulate. A process that looks correct for the first 20 pieces may generate deviations outside the tolerance after several hundred. The balance between performance and stability One of the key challenges is to find a balance between aggressive efficiency and stability. Overly conservative parameters increase the unit cost, but overly aggressive ones lead to: Cost optimisation in series production should always start with stability and only then move on to cycle time reduction. A poorly chosen machining strategy, an inappropriate tool or failure to take process tolerances into account result in costs that only become apparent over time. In series production, such errors are repeated hundreds or thousands of times. Machine park and tools in the context of production predictability In series production, the predictability of machine operation is crucial. Differences in axis rigidity, spindle condition or feed dynamics have a direct impact on quality. Tool wear is one of the main factors destabilising the process. If it is not monitored and planned, it leads to uncontrolled dimensional changes. An effective mass production strategy assumes: A well-chosen machining strategy reduces cutting force fluctuations and stabilises the process. Constant tool engagement, smooth entries and exits, and avoiding sudden load changes are often more important than maximum instantaneous performance. Quality control in CNC series production as an element of optimisation Quality control in series production should not be treated solely as a tool for detecting defects. Its main purpose is to quickly identify trends and prevent problems from escalating. Insufficiently frequent inspections mean the risk of producing a large batch of non-compliant parts. Effective quality control in CNC includes measurements of the first pieces after retooling, periodic checks during the series, and analysis of trends, not just limit values. This makes it possible to react before deviations translate into real losses. Summary Serial production in CNC machining is a process in which costs and quality are closely linked. Attempts to reduce costs without understanding the stability of the process usually lead to the opposite of the intended effect. The greatest potential for optimisation lies in conscious planning: the selection of machining strategies, tools, machines and quality control systems.
Cooling and chip removal in CNC machining – impact on process stability and quality
In CNC machining, it is very easy to focus solely on cutting parameters, tool geometry or machine accuracy. However, in practice, cooling and chip removal often determine whether the process remains stable throughout the entire production series. These are not auxiliary elements. They are an integral part of the process that affects temperature, tool wear, material behaviour and quality repeatability. Especially with long series or difficult geometries, a lack of control in this area quickly leads to problems that are difficult to link to a single specific cause. Cooling and chip removal as elements of CNC machining process stability CNC process stability means that, with constant parameters, we obtain a predictable result: the same dimensions, the same surface quality and similar tool wear. For this to be possible, the conditions in the cutting zone must be as constant as possible. The coolant is responsible for heat removal, friction reduction and chip transport. Chip removal prevents them from coming into contact with the tool and workpiece again. If any of these elements ceases to function properly, the process begins to “break down” – often gradually and imperceptibly. The role of temperature and chips in long-term process stability Chips remaining in the machining zone are one of the main sources of process variability. They can be re-cut, wedge between the blade and the material, or block the coolant flow. As a result, the temperature rises locally and the cutting forces change. This may not be noticeable in a short series. In long series production, however, it leads to a gradual deterioration in surface quality, an increase in dimensional variation and a reduction in tool life. The influence of cooling conditions on the behaviour of tools and the material being machined Stable cooling maintains predictable blade operating conditions. With insufficient or uneven cooling, the tool operates at a higher temperature, which promotes accelerated wear, microcracks on the edge and the formation of build-up. The workpiece material also reacts to temperature changes. Especially in aluminium and alloy steels, changes in cooling conditions affect friction, chip formation and surface quality. Thermal load on tools and machining repeatability A tool subjected to variable thermal loads wears unevenly. This means that even with the same programme parameters, the actual cutting conditions change over time. In practice, this manifests itself in dimensional drift or the need for corrections during a series. Constant cooling conditions allow tool wear to be kept within a predictable range and replacement to be planned in a controlled manner, rather than only after deficiencies have arisen. Material deformation resulting from improper cooling An increase in temperature in the cutting zone causes the material to expand. After cooling, the part returns to its original dimensions, which can result in geometric errors. This problem is particularly noticeable with thin-walled components, long workpieces and precision fits. Uneven cooling also promotes the formation of internal stresses, which may only become apparent after machining or during further operations. Chip removal in CNC machining as a process risk factor Accumulated chips can periodically block the cutting edge, causing load spikes and momentary vibrations. Each such disturbance accelerates tool wear and reduces the stability of the entire process, even if the parameters in the programme remain unchanged. Chips as a cause of micro-damage to surfaces Chips moving across the machined surface act as an abrasive material. They cause scratches, pitting and local damage that is difficult to remove during the finishing stage. The problem is exacerbated in deep pockets and enclosed spaces. The influence of workpiece geometry on chip behaviour during the process The geometry of the workpiece largely determines how chips are evacuated. Narrow channels, deep pockets or sharp corners require a conscious choice of cooling strategy, tools and cutting direction to avoid chip accumulation. Cooling and chip control strategies in the context of mass production stability In series production, it is crucial to maintain identical cooling conditions for each workpiece. This includes not only the pressure and direction of the coolant, but also its cleanliness and stability of parameters over time. Even slight changes can lead to quality differences within the same series. The relationship between cooling strategy and process predictability A well-chosen cooling and chip removal strategy increases process predictability. It facilitates the planning of cycle times, tool changes and quality control. As a result, it reduces the number of downtimes and unplanned adjustments. Summary Cooling and chip removal in CNC machining are key factors in process stability and product quality. Their role increases with the length of the series, the complexity of the geometry and the quality requirements. Conscious design of these elements allows you to reduce variability, improve repeatability and increase process safety. It is these details that determine whether CNC machining remains stable not only on the first, but also on the thousandth detail.
Summary of 2025 at SIM Gdynia
The year 2025 was a time of intense work, important decisions, and achievements that strengthened SIM Gdynia’s position as a trusted partner in the field of precision CNC machining throughout Europe. We implemented new projects, won prestigious awards, expanded our machine park, supported the local community, and broadened our expertise in sectors of strategic importance to the country. We invite you to take a short journey through the past months and review the most important events that shaped this intense year—and there were many of them. OTIF95 Award from the KION Group—confirmation of reliability One of the key events of 2025 was our winning of the OTIF95 Supplier Performance Award, presented by the KION Group for timely and complete deliveries. This award confirms that our production processes, logistics, and quality standards meet the expectations of a global leader in the intralogistics industry. The components we manufacture support the operation of advanced transport and storage systems around the world. The OTIF95 award is a credit to the entire SIM Gdynia team and proof that we consistently maintain the highest reliability of delivery. Partnership with KS Chwaszczyno – we invest in young athletes In 2025, we signed an official partnership agreement with the Chwaszczyno Sports Club. We believe that the strength of industry lies not only in technology, but also in the community in which we operate. This is an important initiative for us – we invest in the development of young people, passion, discipline, and values that are consistent with the culture of SIM Gdynia. ITM INDUSTRY EUROPE 2025 trade fair – investments and new directions for development On June 4, the SIM Gdynia team participated in the ITM INDUSTRY EUROPE fair in Poznań – one of the most important events presenting Industry 4.0 trends and technologies. 4 czerwca reprezentacja SIM Gdynia uczestniczyła w targach ITM INDUSTRY EUROPE w Poznaniu – jednym z nDuring the fair, we analyzed solutions in the field of automation, robotics, and advanced CNC technologies, and held a series of talks with production system suppliers. This event confirmed that we will consistently pursue digitization, automation, and the development of technological competencies. Obtaining a license from the Ministry of Internal Affairs and Administration – a new chapter for SIM Gdynia On July 4, we obtained a license from the Ministry of Internal Affairs and Administration (No. B-090/2025) to manufacture and trade in technologies for military and police use. Second Forbes award – confirmation of stable year-on-year growth For the second time in a row, we were among the companies honored at the Forbes Family Business Forum 2025. For us, this is a special confirmation of stable growth, consistency in the implementation of our strategy, and the effective combination of family tradition with modern technology. We have been developing as a family business since 1978, and today, with over 100 CNC machines and specialization in sectors requiring the highest precision, we are one of the most trusted subcontractors in the region. We dedicate this award to both our team and our customers. Without the trust of our partners and the work of our entire staff, this success would not have been possible. MSPO 2025 – a strong presence in the defense sector The MSPO 2025 trade fair in Kielce is the largest defense industry event in Central and Eastern Europe. This year’s edition was special because, for the first time, we presented ourselves as a company with a license from the Ministry of Internal Affairs and Administration for the production of military and defense technologies. We would like to thank everyone who visited our stand. Numerous conversations and interest in our offer confirmed that SIM Gdynia’s competencies meet the current needs of the security and defense sector. Summary The year 2025 was a challenging time for us, but above all, it was full of evidence that we are consistently moving in the right direction. The awards we have won, our expanded scope of activity, technological investments, and new partnerships have strengthened our position as a stable, modern company ready for new challenges. We would like to thank our customers, partners, and the entire team for their trust and for building our success together. We are entering the new year with energy, plans, and the conviction that the best projects are still ahead of us.
Holiday and New Year’s greetings from SIM Gdynia
The end of the year is a time for the entire manufacturing industry to take stock, reflect, and make plans for the coming months. At SIM Gdynia, this is a moment when we pause for a moment to express our gratitude to everyone who contributes to our projects and development – our customers, business partners, and our team. On the occasion of the upcoming Christmas and New Year, we would like to share a few words of thanks and best wishes. Wishes for our contractors and business partners Thank you for your cooperation, trust, and joint projects in the past year. Each order, consultation, and conversation was not only a professional challenge for us, but also confirmation that our work truly supports your technological and business goals. We wish you a peaceful and joyful Christmas. May this time bring you respite and the opportunity to recharge your batteries before the challenges ahead. In the New Year 2025, we wish you stable projects, effective decisions, and partnerships that will strengthen your market advantage. May each stage of your activities bring satisfaction, security, and measurable results. Wishes for the SIM Gdynia team We would like to thank all our employees for their professionalism, responsibility, and daily work, which allows us to fulfill even the most demanding orders. Your knowledge, experience, and commitment build the quality for which we are known. We wish you a peaceful and warm Christmas with your families. May it be a time of rest and regeneration. In 2025, we wish you health, prosperity, and satisfaction from your daily duties. May the coming year bring a sense of growth and stability on which to build further professional and personal successes.
What is High Speed Machining (HSM)? A guide to high-speed CNC machining from the basics
For several years now, high-speed CNC machining has been one of the areas that has had the greatest impact on the efficiency of modern manufacturing plants. With the development of high-speed machines, new tool geometries, and advanced CAM systems, an approach known as High Speed Machining (HSM) has emerged. It is not just a matter of “working faster.” HSM changes the way we think about process preparation, tool load planning, and path control—especially where short cycle times, stability, and high surface quality are required. That is why it is increasingly becoming the standard in industries working with demanding materials and complex geometries. In the rest of this article, we describe the most important principles of HSM, how the process is carried out, and the areas where this method yields the most measurable results. High Speed Machining – basic definition In the simplest terms, High Speed Machining (HSM) is a machining strategy in which: In many industrial applications, HSM is considered to be working at spindle speeds above 10,000 rpm and cutting speeds ranging from several hundred to over 1,000 m/min (depending on the material and tool geometry). However, this is not a rigid limit – the key is the approach, i.e., high dynamics with a small, well-controlled chip cross-section. High-speed CNC machining vs. conventional machining In conventional machining, increasing productivity usually means more pressure – the cutting depth, tool engagement width, and cutting forces increase. This leads to increased loads on the spindle, the clamping device, and the workpiece itself. The temperature in the cutting zone rises and the chip has relatively long contact with the cutting edge. In high-speed CNC machining typical of HSM, the process is different: This approach works particularly well for complex 3D surfaces in parts such as molds and dies, in hardened materials, and for machining pockets and contours, where both productivity and surface quality are important. Tools, holders, and machines for HSM High Speed Machining requires a tool-holder-machine system that is capable of operating stably at high dynamics and high rotational speeds. The key elements are: The high dynamics of the entire process also make the quality of the workpiece clamping very important. Any inaccuracy in the fixture, lack of support, or looseness in the clamping can result in instability and reduced dimensional accuracy. Applications and benefits of High Speed Machining HSM is particularly popular in industries where a combination of complex geometry, high accuracy, and difficult materials is important: The main benefits are: Limitations and challenges of HSM High Speed Machining is not a universal solution for every workpiece and every machine. The main limitations include: Therefore, when implementing high-speed CNC machining, it is advisable to follow the recommendations of tool manufacturers and, where possible, use stability analyses to help select a spindle speed range that ensures smooth operation. Summary High Speed Machining (HSM) is a comprehensive approach to cutting – from the selection of the machine, tools, and holders, through path strategies, to parameter settings. When used correctly, high-speed CNC machining can significantly reduce manufacturing time, improve surface quality, and increase process stability, especially with demanding materials and complex geometries. However, the key to success is conscious implementation – with an assessment of the machine park, selection of the right details, and systematic improvement of parameters based on actual results, not just theoretical assumptions.
CNC machining of thin-walled parts – how to reduce vibrations and deformations?
Thin-walled bodies, rings, slimmed-down housings – all these elements look inconspicuous, but technologically they can be a real challenge even for experienced contractors. Where a solid element remains stable, a thin wall begins to act like a membrane – it reacts with vibrations, deflection, and deformation when removed from its mounting. That is why CNC machining of thin-walled parts requires a completely different approach than standard milling or turning. Based on our more than 45 years of experience in CNC machining, we discuss the most important challenges associated with such geometries and practical methods for reducing vibrations and deformations – from machining strategies and tool selection to proper fixture preparation. We invite you to read on. Thin-walled parts – what does this mean in practice? In workshop practice, thin-walled elements are not assessed solely on the basis of their nominal wall thickness. Much more important is the ratio of wall height to wall thickness (H:T), which determines the stiffness and how the part will behave under cutting load. The higher this ratio, the greater the susceptibility to deformation. This is most easily seen in the behavior during machining: Thin-walled parts are typical in industries where designers strive to reduce weight: aerospace, energy, machinery, and automotive. Relieving the load on components reduces material wear and dynamic loads, but at the same time requires the machining technology to be able to ensure adequate rigidity and accuracy on components that are inherently flexible. This is why CNC machining of thin-walled components is a process carried out on components that are not designed to be rigid – and this is the main technological challenge. Where exactly do vibrations and deformations come from? In thin-walled components, it is not only low rigidity that is decisive, but also the way the material reacts to variable loads during cutting. In practice, three phenomena overlap, which can completely change the behavior of the part during machining. If we add to this the stresses generated during rough machining, the influence of temperature, and the limitations resulting from clamping, it is easy to understand why thin-walled components are so susceptible to geometric changes. Clamping – the foundation of CNC machining of thin-walled components Without the right tooling, even the best cutting parameters will not ensure a stable process. Thin-walled parts require full, even support – point clamps or grips in a single location can cause more deformation than the machining itself. Typical approaches to clamping include: Added to this is the issue of the tool — shortening the reach, using rigid holders, and eliminating backlash. The entire “fixture + holder + tool” system must work as a single, rigid block. Cutting strategies – lighter, more frequent, with control over allowances When CNC machining thin-walled parts, aggressive, deep passes almost always lead to vibrations and loss of geometry. An approach based on controlled, multi-stage machining with limited wall loading gives significantly better results. In practice, it is worth using: The goal is not to “remove material” quickly, but to consistently control deformation at every stage. Cutting parameters and tools – how to reduce cutting forces? In thin-walled components, it is crucial to limit lateral forces that directly cause deflection. This can be achieved on several levels: Cutting parameters Instead of one deep pass, several shallower passes with a smaller cutting width are used. In some cases, it is better to work at higher speeds with a smaller feed per tooth to avoid areas of instability. Tool geometry Sharp tools with a positive rake angle (“soft cutting”) generate less force than geometries designed for aggressive cutting. Milling cutters with variable tooth spacing or anti-chatter geometry help to dampen vibrations. Tool holders Hydraulic, heat-shrink, and vibration damping systems can dramatically improve stability at longer reaches. In practice, they are often a more cost-effective choice than lengthy attempts to stabilize the process with a standard holder. Summary – 5 rules for CNC machining of thin-walled parts For clarity, we have compiled the most important conclusions in a short checklist: In many cases, a certain level of deformation after release of the clamping is unavoidable. It is crucial to anticipate this phenomenon and take it into account in the machining plan, rather than correcting errors only in the final inspection.
Turning inserts in CNC machining – markings, types, and practical applications
Turning inserts are one of the key elements of the CNC machining process. Their selection determines: process stability, tool durability, surface quality, and the ability to maintain the required tolerances. Manufacturers place information about the material application and recommended cutting parameters on the packaging of the inserts (usually packed in sets of several pieces). The correct interpretation of these markings is the foundation of proper technology. In this article, we discuss inserts used on lathes: for rough turning, finishing, threading, grooving, and cutting. First, we would like to emphasize that it is always worth verifying the detailed catalog data with the tool manufacturers. Material designations for inserts – groups P, M, K, N, S, H Manufacturers of turning inserts classify materials according to a standardized system: Each insert grade has a specific carbide composition, coating type, and geometry adapted to a given group. For example, inserts for stainless steel (M) are designed for ductile materials prone to build-up, while grades S and H must withstand high temperatures and intense abrasive wear. One geometry, different materials – where are the limits? In production practice, a single insert shape can be manufactured in different grades, intended for different materials. Compromise solutions are often used: It is therefore crucial to make a distinction – the geometry (shape of the insert) may be the same, but the grade must be selected according to the material being machined and the machining conditions. Inserts for rough turning Rough turning requires inserts with high edge strength and the ability to work with higher feed rates. This group includes WNMG, CNMG, and DNMG, among others. WNMG Inserts used in MWLNL/R holders are most often available with corner radii of 0.4 / 0.8 / 1.2 mm. In practice, a radius of 0.8 mm is most commonly used, less often 1.2 mm. A typical size is, for example, 0804. The tool is the basic solution for rough turning of small and medium-sized workpieces. CNMG DCLNL/R holders are designed for larger workpieces. They use inserts in sizes 12 and 16, with radii as for WNMG. The design provides greater rigidity of the system at larger diameters and lengths. DNMG DNMG inserts (e.g., 1506) with radii of 0.4 and 0.8 mm are the classic solution for rough and semi-rough machining in a wide range of materials. They combine good strength with the ability to shape contours. Inserts for finishing Finishing requires inserts with smaller corner radii and stable, predictable performance in order to achieve the target dimensions and roughness. DCMT Inserts available in small and large versions, with radii of 0.2 / 0.4 / 0.8 mm (0.8 – in larger variants). Used for semi-finishing and finishing passes. TNMG Finishing inserts with radii of 0.2 / 0.4 / 0.8 mm. Used to “guide” the dimension within tolerance. After each insert replacement, it is necessary to check the dimension (e.g., with a transameter) and, if necessary, correct the tool in the control system. CCMT rhombic inserts Available in small and large versions with radii of 0.2 / 0.4 / 0.8 mm. Used for finishing cylindrical and end surfaces as well as contours, especially in areas with limited access. VBMT Inserts with a similar application to TNMG. Four-edged (0.4 / 0.8 mm) and single-sided (0.2 / 0.4 / 0.8 mm) versions are available. Selected where the geometry of the SVJ holder provides better access to the machined surface. Thread cutting inserts Thread cutting inserts are divided into solutions for internal threads (IR/IL) and external threads (ER/EL), in trapezoidal, metric, inch, and other profiles. Inserts for grooves, channels, and cutting Channel cutters Cutters Inserts with widths from 0.5 to 3.0 mm, mainly used on bar lathes for cutting off workpieces. Practical application – a few rules In technological practice, the following rules can be adopted: Area of application Characteristics and selection rules Rough turning Used as basic tools for high-volume machining. The most commonly selected radius is 0.8/1.2 mm. The selection of the insert grade depends on the material and the required performance. Finishing turning Used to achieve the required dimensions and surface quality within the tolerance. After each insert replacement, it is necessary to check the dimensions and correct the settings if necessary. Thread turning The insert is selected individually based on the thread profile and the requirements of the drawing. There are no universal solutions — each geometry requires the right tool. Grooving and cutting The selection depends on the width and depth of the groove and the material of the workpiece. The selection of a turning insert should be based on both the manufacturer’s catalog data and the experience of the technology and production team. The combination of these two sources of knowledge allows for a stable, repeatable CNC machining process and optimal use of tools.
Precise hole machining in CNC machining – drilling, reaming, and boring in practice
In CNC machining, one of the areas that requires very high repeatability and control is hole making operations. These are processes that combine requirements for dimensional accuracy, tool stability, and proper planning of the sequence of operations. Only their correct combination allows you to obtain a hole with parameters consistent with the design assumptions. At SIM Gdynia, we perform hole machining in steel, cast iron, and aluminum alloys on a daily basis, both in prototypes and in series production. Each of these materials requires a different approach, and the choice between drilling, reaming, and boring always depends on the specifics of the part and the expected accuracy. In the rest of this article, we discuss how the CNC hole machining process is planned and carried out in practice, and what techniques we use to maintain the required dimensions, axiality, and surface quality. Why are holes so critical in CNC machining? Holes are the element that transfers the function from the design to the actual part. In typical machine components, they are used for: This is why CNC machining of holes rarely ends with drilling alone. Drilling, reaming, boring – what is each responsible for? In simple terms, we can say that: Drilling provides sufficient accuracy for most mounting holes. When precise fits are required, the process is extended with additional steps: after drilling, the hole is reamed to correct the direction, and the final dimension is achieved by boring. Reaming is particularly important where several holes must maintain mutual geometry or where the hole serves a positioning function – it allows errors made during drilling to be removed and prepares the hole for accurate finishing. Reaming – a stable way to achieve accurate dimensions Effective reaming requires leaving the correct allowance after drilling. Too little allowance prevents cutting, and too much causes vibration and deterioration of surface quality. The correct value depends on the diameter and material, so it is selected according to the tool manufacturer’s recommendations. The operating parameters of a reamer differ from those of a drill. The speed is lower and the feed rate is higher, which improves surface uniformity and process stability. For deep holes or difficult-to-machine materials, internally cooled reamers are used, which provide better heat dissipation and longer tool life. Boring – precise geometry correction Boring is used where drilling alone does not guarantee axiality or correct hole geometry. It allows the hole path to be corrected and prepared for further finishing. We use them, among other things, for bearing seats, axial holes, and systems where several holes must maintain a precise mutual position. Boring heads allow for precise diameter adjustment, which makes it easier to maintain tolerances even in more demanding applications. Fits and tolerances – how to combine ISO fits with the realities of CNC machining The ISO fit system with a hole base (e.g., H7, H8) is standard in the design of machine components. For diameters in the range of 10–50 mm, the H7 tolerance is usually several to a dozen micrometers – a level that cannot be achieved consistently by drilling alone. At SIM Gdynia, we apply a simple rule – if a hole has a critical fit, we plan an additional reaming or boring operation. This gives the designer the certainty that their fit will be reflected in the actual part, and us the certainty that the CNC machining process is stable and predictable. Summary Precise hole machining requires a well-planned sequence of operations and a conscious selection of tools. In practice, the most important factors are the quality of the first pass, geometry control at the boring stage, and the repeatability of dimensions achieved by reaming. We most often analyze: At SIM Gdynia, we combine these elements into a single coherent technological process, thanks to which we are able to maintain both the dimensions and geometry of the holes within the required tolerances – regardless of the material, series, or complexity of the component.
From documentation to stable production – the work of a technologist at SIM Gdynia
In modern CNC machining, there is a lot of talk about operators, setters, and quality control, but it is the technologist who is responsible for the foundation of the entire process. It is the technologist who defines how a part is to be made, selects the tools, determines the sequence of operations, and prepares the program that the machine will later execute. The repeatability, safety, and efficiency of production depend on the technologist’s decisions. At SIM Gdynia, the role of the technologist is clear: to translate the requirements from the customer’s drawing into a process that will be stable in series production, maintainable over time, and compliant with quality requirements. Below, we present how this works in practice, exactly as we do it every day. From inquiry to technology concept The process begins in the sales department, which receives an inquiry along with a technical drawing or 3D model of a new part. Before a feasibility statement is issued, the documentation is sent to the technologist. The technologist assesses whether the part can be manufactured under the specified production conditions. The technologist analyzes the material, tolerances, geometric requirements, and complexity of the part. They check the number of operations required, the availability of machines and tools, the need to purchase additional equipment, and the possibility of fitting within economically justified cycle times. On this basis, a preliminary technology concept is developed: the sequence of operations, the selection of machines, tools, and equipment, as well as the estimated processing time. This document is the basis for preparing a quote, which the sales representative presents to the customer as an offer to manufacture a new part. Operation plan – from the saw to the milling machine When the inquiry becomes a real order, the technologist prepares a detailed operation plan. At this stage, he determines how many steps will be involved in the production of the part and what machines will be used. At SIM Gdynia, we use an internal abbreviation to describe the sequence of processes, for example, P–T–T–C, where P stands for material preparation, T for turning, and C for milling. It is crucial to arrange the operations in such a way that the entire process is stable and economical. The technologist analyzes the machining bases, limits the number of retooling operations, and avoids unnecessary movement of the part between stations. Only after a logical and feasible plan has been established can we move on to the next stage, which is the preparation of programs for CNC machines. Programming and tool selection The preparation of CNC programs is one of the key stages of a technologist’s work. Based on the 3D model, technical documentation, and previously established technology, tool paths are created, along with the selection of feeds, rotational speeds, and machining strategies. The goal is to create a process that is stable, efficient, and repeatable in series. If the production of a part requires tools that are not part of the standard equipment, the technologist determines their specifications and orders their purchase. This applies to both special tools and the ongoing replenishment of the basic range of tools needed for production. This ensures that the machine has a complete set of equipment before a new order is placed. After preparing the programs, the technologist provides the planning department with information on the cycle time, type of tooling, and the specific machine on which the process should be carried out. On this basis, the part is entered into the schedule and sent for processing. Start of production – setup, control, stabilization When the part reaches the designated machine, the technologist enters the program and supervises the process setup. This stage includes the selection of bases, tool zeroing, and verification of compliance with the documentation. The first pieces are always treated as a trial stage, during which measurements are taken and minor adjustments are made. Setting up the first pieces The operator and technologist jointly observe the behavior of the tools, surface quality, and dimensional stability. If it is necessary to adjust the parameters or make minor changes to the trajectory, they are introduced at this stage. Transition to serial production Once the process is stable and the measurement results are repeatable, the order goes into serial mode. Nevertheless, the technologist remains on standby to provide support, as the machining conditions may need to be adjusted during the production of the batch. Tools – when standard clamping is not enough Many parts, especially forgings, castings, or irregularly shaped components, require individual clamping solutions. Standard vices or jaws will not provide stability or tool access, so it is necessary to prepare dedicated tooling. Tooling design At SIM Gdynia, a designated technologist is responsible for tooling design. Their task is to prepare the clamping so that: Machining on the tool Only after the tool has been made and checked is it possible to safely machine complex parts that cannot be clamped in the standard way. Drawing changes and technology updates During cooperation with customers, modifications to details often arise: changes in chamfers, diameters, tolerances, or additional features. Each such update requires a review of the entire technology. Technologist’s response to changes The technologist analyzes the new documentation, updates the CNC programs, and makes corrections to the process cards. Sometimes this takes a moment, and sometimes it requires a complete overhaul of the machining concept. The best versions of the programs At the same time, operators and foremen refine the programs on the machine, adapting them to the working conditions of a specific workstation. When the program achieves full stability and optimal cycle time, the technologist saves it as a reference version to maintain full repeatability in subsequent series. The technologist as a link between the office and the shop floor The role of the technologist combines engineering work with manufacturing practice. On the one hand, they analyze documentation, tolerances, and customer requirements, and on the other, they know the machines, tools, and real limitations of the process. A key function in the