Keep Your Edge: Maintaining Your Shop's Grinding Wheels
Whether you're managing a small operation with a handful of machines or a large shop, keeping your equipment in perfect shape is essential to delivering quality work for your customers. If you have one or more grinding wheels, then you likely already know how improperly maintained wheels can negatively affect your shop's output. Fortunately, keeping these machines in proper working condition is not expensive or difficult. This article will guide you through the basics of maintaining your shop's grinding wheels to prevent imperfections in your workpieces.
The Fundamentals: How Wheels Wear
When a wheel grinds against a workpiece, the mechanical work is performed not by the entire surface of the wheel, but by small embedded bits of abrasive material. As a grinding wheel performs its cutting action, two things happen: the abrasive materials wear down, and the wheel itself can become unbalanced. An unbalanced wheel will "skip" across the work surface, potentially producing uneven results or causing other issues. A grinding wheel that has lost most of its abrasive material will perform poorly, take longer to make cuts, and negatively impact the quality of your shop's work. This wear can happen due to choosing an improper wheel for the workpiece, but it will also tend to occur over time anyway.
Truing vs. Dressing
The two maintenance operations commonly performed on grinding wheels are truing and dressing. Since these two operations are often performed together, many inexperienced operators may use the terms interchangeably or not fully understand how they differ. Although there are good reasons to dress a grinding wheel after truing, these are distinctive operations that accomplish drastically different tasks.
Truing, as the name implies, is about returning a grinding wheel to "true" round. Grinding wheels may be imperfectly shaped on delivery, or they may lose their shape over time through use. A grinding wheel that is clearly imbalanced or that chatters requires truing. By contract, dressing a wheel is about removing dull abrasive material to expose a sharp cutting surface. Dressing is commonly performed after truing since the process of truing can cause the wheel's surface to lose its edge.
Choosing a Grinding Wheel Dressing Unit
Grinding wheel dressers may seem simple at first glance, but choosing the right one is not as straightforward as it appears. In addition to selecting a tool that is durable, it is necessary to choose one that will function properly with your particular grinding wheel. Since grinding wheels are designed for various hardnesses, dressing tools must be selected with this in mind. Your wheel's grit and the grit of your abrasive dressing tool must be matched to clean the wheel without removing more particles than necessary. Most suppliers of dressing tools provide charts matching these two values, so be sure to consult these before making any tool purchasing decision.