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CBN wheels have been growing steadily in usage since 2014 because the demands on precision grinding have risen exponentially. Superabrasive grinding is a more specialized and costly endeavor than conventional grinding. For demanding jobs involving specific forms and geometries, standard super abrasive wheels are often ill-equipped for the job.
Why Standard Wheels Fall Short
REZZ is at the forefront, developing customized diamond and CBN grinding wheels to meet challenging industrial manufacturing needs with greater efficiency and precision-while also reducing overall costs for their customers. Why Standard Wheels Fall Short A standard superabrasive grinding wheel is designed to be a Jack of all trades. It’s built to general specs so that it can be used to cut everything from steel and carbide to superalloys in a wide variety of operations. “Unfortunately, a wheel that’s all things to all people seldom delivers optimum performance for any one job.
How Custom CBN Wheels Address Unique Applications
Superabrasive wheels also have limitations compared to standard abrasive grinding wheels in that they come manufactured to form; there is little that the user can do to dress or grind the wheel after purchase. Changing its shape is highly discouraged because the expensive diamond or CBN grit layer would be ground away, and, due to this design constraint, off-the-shelf superabrasive wheels offer limited options in terms of grit size, concentration and bond. Custom CBN Wheels for Specialized Applications Since customization is key, custom CBN wheels give operators exactly what they need – including grit size, concentration, the best bond formulation and specific material properties.
They can choose either angular grits, which grind and cut efficiently and often generate sharper edges, or blockier shapes, which can handle more pressure and wear.
Different bond systems can either help a wheel sharpen itself to maximize wear (resins, which typically hold around 25% abrasive), or contribute to a longer life up to 10 times longer (vitrified, which hold around 50% abrasive). Switching from a standard resin bond wheel to a custom vitrified formulation may cost more initially but typically pays for itself by increasing performance, consistency and tool life significantly.
The Technology Driving Customization
When we developed a custom vitrified formulated wheel for them, their wheel life increased by 450%”, says Rezz Technical Director, David V. These wheels offer substantial benefits as compared to standard off-the-shelf superabrasive products, which cannot compete as they can be formed to specific geometry by the designer as opposed to being dressed by the customer after purchase. 3D printing is one of the revolutionary technologies opening up new possibilities. Precision-structured vitrified CBN grinding wheels have been created with 3D printing and can be designed to improve tool performance “by optimizing surface slot features, internal cooling channels and porosity, enhancing chip flow and minimizing grinding forces”.
3D printing for an internal diameter grinding tool has been used to “achieve rates up to 40 percent higher than wheels without a patterned geometry, along with higher removal forces and improved process stability,” according to researchers from Florida Atlantic University in their recently published study on internal diameter grinding.
When to Invest in Custom CBN Wheels
Most job shops who process many different geometries in varying lot sizes, investing in custom wheels will not be practical. They change the workpiece materials so frequently that custom specifications will no longer be effective and as cost-prohibitive. However, if a company produces thousands of parts of a particular kind in a run, then the effort and cost of process optimization for a custom wheel is a sound investment.
Adjusting a grit size or concentration, or the bond type and grade of your existing superabrasive product will increase efficiency between 10 percent and 20 percent, or if moving to a different class of wheel, up to 100 percent, the company explained. “We work very closely with our customers on these types of projects and look for the best overall value based on their individual requirements,” David explains. Custom CBN wheels are the answer to the increasing demands placed on precision grinding by giving manufacturers the flexibility they need to optimize their performance.