Surface Grinder Technology Parameters
Surface grinding machines are used in a variety of industrial applications. Whether it’s to create a smoother surface, hone in a substrate or create a uniform finish on a machined part, surface grinders are used to produce higher quality surfaces, while offering the ability to be more precise and cost effective than other grinding methods.
Surface grinders are often used to produce flat, angular, and parallel surfaces on workpieces, as well as create squareness, parallelism, and perpendicularity. When choosing the right surface grinder for a given application, a wide variety of parameters must be taken into account. The following section examines each of these parameters in greater detail, along with the functions and importance of each in surface grinding.
Spindle Speed
The spindle speed is the most important parameter to consider when selecting a surface grinder. The spindle speed, also referred to as the revolutions per minute (RPM), determines how quickly the wheel spins and impacts the results of the grinding operation. The wheel must be spinning quickly enough to evenly remove material, but slow enough to keep the wheel and workpiece from overheating or experiencing excessive levels of wear.
Wheel Diameter
The wheel diameter is measured in inches and is important in determining the amount of material that can be removed from the surface. Larger wheels are able to grind larger surface areas, while smaller wheels can be used for detailed grinding and reach into tighter angles and spaces. The wheel diameter also affects the cutting speed, and should be chosen to match the application and expected cutting rates.
Wheel Grit Size
The wheel grit size is responsible for the particle size of the material that is being ground. Coarser grits have larger particles, which can provide the desired results when a large amount of material needs to be removed quickly, but will be too aggressive for finer grinding finishes. Finer grits have smaller particles and are ideal when more precise cuts are needed.
Feed Rate
The feed rate is a measure of the speed at which the grinding wheel moves over the surface of the workpiece. This speed is typically determined in inches per minute and is a critical parameter that impacts the quality of the surface grind. If the feed rate is too slow, the grinding wheel will not travel across the entire surface of the workpiece, while a feed rate that is too high will cause wear and tear to the grinder and the wheel.
Spindle Travel
The spindle travel is the total distance the wheel can move across the workpiece in a single pass. Generally the larger the area to be ground, the greater the spindle travel distance is needed. The longer the spindle travel distance the more material that can be removed in a single pass, but the less accuracy that can be attained due to the slower speeds.
Table Traverse Speed
The table traverse speed is the distance that the table travels per minute. This is particularly important when long parts are being ground in multiple passes. A slower traverse speed allows more material to be removed in a shorter period of time; however, it can also cause the grinder and wheel to overheat and could negatively impact the overall accuracy of the surface grinding.
Coolant
Coolant is typically used when grinding metals and is assigned to flush away material and keep the wheel and grinder streamlined while providing a coolant barrier against heat build-up. The amount of coolant used is extremely important as too much coolant can cause the wheel to clog and may cause the workpiece to become damp, while too little results in unpredictable heat buildup and affects the wheel integrity, wheel performance, and accuracy of the finished part.
Conclusion
Surface grinding is an important process for many industrial applications, requiring the knowledge of a number of parameters. Spindle speed, wheel diameter, wheel grit size, feed rate, spindle travel, table traverse speed, and coolant are all important considerations when selecting a surface grinder. Understanding these parameters and their role in the grinding process is key to getting the desired results from a surface grinder.
