In this article we aim to emphasise the advantages of choosing the correct dressing tool for specific applications to ensure optimal performance and extended lifespan of your grinding wheels. Dressing and truing are common terms used in precision grinding applications. Although using the same tool in both instances, each application poses its own unique characteristics.
When a grinding wheel’s form or shape is no longer within desirable limits, and or no longer within the specific tolerance limits of the wheel, trueing known as a shaping process will be applied, this will bring the wheel back into proper form, or shape for its surface to run concentric to the spindle axis of the grinder or to the necessary tolerance requirements.
The Role of Dressing in Grinding Wheels Maintenance
Dressing on the other hand is a process where the wheel is reconditioned to such an extent that it’s cutting performance is once again improved. As a grinding wheels’ sharp edges wear away on application, metal particles derived from the workpiece gets loaded into the wheel. To remove these together with the dull grain, “dressing” is required to expose new sharp grains, which restores maximum performance to the wheel.
With the advancement of grain and bonding systems, optimising the overall grinding process is of utmost importance to find the perfect balance between cost and efficiency. Choosing the correct dressing tool will reduce overall wheel wear, and aid in maximum wheel performance.
Understanding Single Point Diamond Dressers and Their Applications
Dressers are available in a multitude of derivatives ranging from abrasive sticks to single point, multi point, diamond rotary and or star-shaped dressers.
Single point diamond dressers have a single diamond sintered onto a metal shank varying in different sizes from 0.25, up to 1.0 carat. To choose the correct single point dresser, one would consider the size of the grinding wheel, the smaller the wheel, the smaller the diamond, the bigger the wheel, the bigger the diamond requirement. The single point diamond dresser is positioned on the centreline of the grinding wheel and slightly offset to the left, canted between 10 to 15 degrees in the direction of the wheels rotation.
The above method aids the diamond from not digging into the grinding wheel, reducing vibration and extending dresser and wheel life. It is however to be noted that single point diamond dresser must be rotated by an eight to retain a sharp point, reducing the change for the diamond to become flat and unusable.
Read More: GRINDING TECHNIQUES SERVICING THE PRECISION GRINDING INDUSTRY
Improving Efficiency with Multi-Point Dressers
Multi point diamond dressers contain as the word implies multiple diamonds embedded into the metal matrix. This type of dresser is best used on wheels with either straight or tapered surfaces, one of the main advantages of a multi-point diamond dresser compared to that of a single point is that it doesn’t require any rotation. As the diamonds are embedded in a metal matrix they are shelf sharpening, providing longevity of up to ten times more compared to single point diamond dressers depending on the application.
Their bigger surface contact area allows for them to be used at a faster traverse speed enabling a faster dressing rate. By using a faster traverse speed, the grinding wheels’ surface is open and perfectly suited to rough grinding operations. Where a finer finish is required from the same wheel, the traverse speed should be slowed down, effectively closing the face of the wheel, making it act harder, providing a finer finish.
Exploring Star-Shaped Dressers and Dressing Sticks for Grinding Wheels
Star-shaped Dressers, make use of several hardened carbon steel wheels with a special teeth design mounted onto a metal handheld body. The tool is handheld against the grinding wheels’ surface, and as the cutter comes into contact with the grinding wheel’s surface, the cutter begins to spin and act as cutting points that fracture the abrasives grainBest suited to applications on wheels with coarse grain specifications, such as bench grinding wheels, and grinding wheels specific to pedestal grinders used in a variety of machine shops and foundry fettling bays.
Dressing sticks, are mostly manufactured from silicon carbide and pressed into a rectangular shape. Its application is a handheld operation, whereby the dressing stick is applied to a variety of grinding wheels making use of a fine grain specification. The dressing stick is rubbed along the grinding wheel’s face to remove dulled grain.
Final Thoughts
Choosing the correct dressing tool will not only improve the surface finish of a workpiece, but also its dimensional accuracy. Effectively extending the grinding wheels life, cutting ability and efficiency. By selecting the right tool, you ensure consistent performance, reduce operational downtime, and maintain precision over extended use. For more on our range of dressing tools or products on our website, contact one of our Business Development Specialists today on +27 11 271 6400.
Leave a Reply
You must be logged in to post a comment.