Conventional Surface Grinding Machines: Proven Technology for Optimal Results
Metalworking is varied and demanding. Conventional surface grinding machines play a crucial role in this. These machines, which are at home in workshops, production halls and specialised companies all over the world, are among the oldest and most proven machine tools when it comes to precision work.
What are Conventional Surface Grinding Machines?
A surface grinder is a tool that is used to create flat surfaces with extremely high precision. Grinding is a cutting process in which material is removed from a workpiece in small quantities in order to achieve an exact shape, surface quality or dimensional accuracy. In contrast to CNC-controlled machines, which are programmable and work automatically, conventional machines are operated manually, which requires a certain amount of experience and manual skill .
Applications and Benefits of Conventional Surface Grinding Machines
Conventional surface grinding machines are mainly used in metalworking. They are most often used in toolmaking, the automotive industry, mechanical engineering, and aerospace engineering.
A particular advantage of these machines is their ability to produce high-precision and mirror-smooth surfaces. They are also able to carry out precise surface processing even on hard materials such as hardened steel or titanium. Another advantage is their flexibility: even though CNC machines dominate in many areas, the conventional surface grinding machine often offers a faster and more straightforward solution for smaller orders or specific custom-made products thanks to its manual operation.
How a Conventional Surface Grinding Machine Works
Conventional surface grinding machines consist of a grinding head equipped with a rotating grinding wheel. This grinding wheel is driven by the grinding spindle and machines the surface of the workpiece, which is fixed on a magnetic clamping plate or a mechanical clamping device. The rotation of the grinding wheel in combination with the uniform movement of the workpiece, which is firmly clamped on the machine table, creates extremely fine surfaces and structures that are essential for the production of high-precision parts. But what processes are involved, and how is this high level of precision achieved?
Structure and Components of the Surface Grinding Machine
A typical surface grinding machine consists of several main components which, when combined, enable precise machining of the workpiece.
Grinding Head and Grinding Wheel
The grinding head contains the grinding spindle, which drives the grinding wheel at a high speed. The grinding wheel usually consists of extremely hard abrasive grains that are attached to a carrier wheel. The grinding wheel diameter varies depending on the type of workpiece and the desired surface. Materials such as corundum, silicon carbide or diamond are often used as abrasives, depending on how hard the workpiece to be machined is. The grinding wheel rotates at high speed (several thousand revolutions per minute) and its rotating movement removes the smallest material chips from the surface of the workpiece.
Magnetic Clamping Plate (clamping device)
When working with pieces that are made of metals or metallic materials, conventional surface grinders incorporate magnetic clamping plates to ensure the piece does not move during the grinding process.. The table is equipped with an electromagnetic or permanent magnetic device that securely fixes the workpiece. The strong magnet ensures that the workpiece is held securely and firmly in position without the possibility of it slipping due to the rotating grinding wheel. This is crucial to achieving the desired precision as well as maintaining safe conditions.
Machine Table (transverse and longitudinal movement)
The machine table is the moving element of the surface grinding machine. It moves in two axes across the table clamping surface: transversely and longitudinally. These movements allow the workpiece to pass under the grinding wheel so that the entire grinding surface can be machined evenly. The longitudinal movement ensures that the workpiece passes under the grinding wheel along the X-axis (in the horizontal direction), while the vertical movement covers the Y-axis to allow lateral displacements.
Feed Mechanism
The feed is the mechanism that ensures that the grinding wheel gradually penetrates deeper into the workpiece. With each feed, the grinding wheel removes a small amount of material, which makes it possible to gradually create an extremely smooth and even surface. The feed is controlled manually or via hydraulic or mechanical systems. Typically, the removal rate per grinding operation is in the range of a few micrometers (1 micrometer = 0.001 millimeters), which is what makes the grinding process so precise.
Details of the Grinding Process
Positioning and Fixing of the Workpiece
First, position the workpiece on the magnetic clamping plate of the machine table. The magnet is then activated to fix the workpiece securely and stably. If you are working with sensitive workpieces or non-magnetic materials, you can use a mechanical clamping device instead of the magnetic clamping plate.
Adjusting the Grinding Process
Now you set the parameters of the grinding process. These include the speed of the grinding wheel, the feed rate and the penetration depth of the grinding wheel into the workpiece. These parameters depend on the type of material and the desired surface quality.
Start of the Grinding Process
As soon as you start the machine, the grinding wheel begins to rotate at high speed. The machine table moves back and forth so that the workpiece is guided under the grinding wheel in even paths. With each movement, a small layer of material is removed.
Cross Feed and Material Removal
The grinding process is carried out step by step. After each movement of the machine table, the grinding wheel lowers a little so that it moves deeper into the workpiece on the next movement. This is repeated until the desired depth or surface quality is achieved. The precision of surface grinding is achieved by the minimal material removal in each pass.
Surface Finish
A major advantage of grinding compared to other machining processes, such as turning or milling, is the ability to produce extremely fine surfaces. Typical roughness values after surface grinding are in the range of a few micrometers, so that the surface is almost mirror-smooth.
Precision Surface Grinding Machine: Top Challenges
The key to high precision lies in careful control of the feed and grinding speed. Since only a very small amount of material is removed during each grinding pass, the user can closely monitor the process and intervene manually if necessary to achieve the desired result. This requires not only technical understanding but also experience in handling the machine.
One challenge when working with conventional surface grinders is the potential for the workpiece to overheat. The high friction between the grinding wheel and the workpiece can generate a lot of heat that could deform the material or cause stress. To prevent this, a coolant is often sprayed onto the contact surface between the workpiece and the grinding wheel during the grinding process. This coolant reduces the heat and ensures more even machining.
What Do You Have to Consider When Operating Surface Grinding Machines?
When operating surface grinding machines, there are a few important points to keep in mind that are crucial for both safety and the quality of the result. Here are the key aspects you should consider:
Safety Precautions
- Personal protective equipment (PPE) : Wearing safety glasses, hearing protection and, if necessary, protective clothing is essential to protect yourself from flying sparks, noise and sharp-edged workpieces.
- Correct adjustment and maintenance of the machine : The machine should be serviced regularly to ensure that all parts are working properly. Defective or worn grinding wheels must be replaced immediately. We encourage you to use KNUTH USA’s top-tier repair and maintenance service.
- Install the grinding wheel correctly : Before starting the machine, make sure that the grinding wheel is installed correctly and securely fastened. An incorrectly installed or damaged grinding wheel may break during operation, which could be extremely dangerous to the operator and anyone else in the grinder’s proximity.
- Use cooling : Most grinding processes generate frictional heat that can damage the workpiece or grinding wheel. Using coolants helps reduce heat and extend the life of the grinding wheel.
- Know the emergency stop switch : The emergency stop switch must always be easily accessible so that the machine can be switched off quickly in the event of an emergency.
Workpiece Preparation
- Place and secure the workpiece correctly : The workpiece must be securely fixed on the magnetic table or clamping device to prevent it from slipping during the grinding process.
- Keep the workpiece clean : Dust, grease or other residues on the workpiece can affect the grinding accuracy. The workpiece should be cleaned thoroughly before starting.
Machine Settings
- Speed of the grinding wheel : The correct speed is crucial for the successful grinding process. It must be adapted to the material of the workpiece and the grinding wheel used. A speed that is too high can damage the grinding wheel, a speed that is too low can impair the grinding result.
- Feed rate : The feed rate must also be adapted to the workpiece material. A feed rate that is too fast can overheat the workpiece or lead to rough surfaces, while a feed rate that is too slow will unnecessarily prolong the grinding process.
- Control grinding depth : The amount of material removed per grinding operation should be very small (in the micrometer range) in order to achieve the desired precision and surface quality. Removing large amounts of material at once can damage the workpiece or lead to uneven surfaces.
Process Monitoring and Adaptation
- Continuous monitoring : The grinding process should be constantly monitored to ensure that the workpiece is machined evenly and that no unexpected deviations occur. Uneven movement of the machine table or deviations in the grinding noise can be indications of problems.
- Adjustment of parameters : Depending on the workpiece or specific grinding process, it may be necessary to adjust parameters such as feed rate or rotational speed during the process in order to achieve the desired accuracy and surface finish.
Post-Processing and Quality Control
- Check the workpiece : After grinding, the surface of the workpiece should be checked for dimensional accuracy and surface quality. Measuring tools such as micrometers or surface roughness gauges can be used for precise inspection.
- Check the grinding wheel : After grinding, the grinding wheel should be checked for wear or damage. Ensure that the grinding wheel maintains its precision and functionality by regularly maintaining it or reworking it.
- Ensure coolant flow : A constant flow of coolant during the grinding process is important to avoid overheating and thermal stress in the workpiece. It also helps to clean and cool the grinding wheel.
- Coolant quality : Coolants should be checked and replaced regularly, as dirty or old coolant can affect the performance of the machine and damage the workpiece.
- After the actual grinding process has been completed, allow the grinding wheel to run for a while to spin it “dry”. Otherwise, coolant seeping in will reduce the service life of the grinding wheel.
Challenges and Trends
Despite their versatility, conventional surface grinding machines also have their challenges. Manual control requires specialist knowledge and experience. In addition, operation can be time-consuming - especially for complex projects or large production series. In times of increasing digitalization in the trade, more are questioning the role of these machines in the modern workplace. Nevertheless, they are considered indispensable tools in metalworking. They offer the highest precision and flexibility, which are invaluable, especially for custom-made products or small-scale production.
Conventional surface grinding machines put people at the center of the work process and offer them the opportunity to make full use of their manual skills and technical knowledge. This opportunity cannot be replaced by any CNC control system, no matter how sophisticated.
Buy Grinding Machines at KNUTH USA
Are you looking for the ideal surface grinding machine? At KNUTH USA you will find a wide selection of models that are tailored to a huge range of different types of work. Many of our grinding machines and the corresponding accessories are available for immediate delivery. We would be happy to provide you with a customized quote on request and provide you with comprehensive advice. Whether by email or telephone - we will help you find the perfect grinding machine for your requirements.
Comprehensive Service: From Installation to Maintenance
Our service does not end with the purchase of your surface grinding machine. We accompany you during installation and commissioning and offer training so that you can fully exploit the potential of your machine. Our technical support is available to you at all times and thanks to our network of service partners, you can quickly receive help on site. We also have an extensive spare parts warehouse for older machines so that necessary components are quickly available. This way we ensure that your machine remains reliable and ready for use in the long term.
