Automated Deburring/Finishing Speeds Throughput

May 1, 2014

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By automating deburring operations rather than performing secondary finishing processes offline, Orange Vise Co., Union City, CA, a manufacturer of CNC machine vises and quick-change fixturing components, has eliminated several time-consuming and laborious processes—processes that had been slowing the shop down. So says company founder Eric Sun, who emphasizes that his company’s use of advanced abrasive technology allows machining-center operators implement in-process surface finishing.

To remove burrs during fine engraving, Orange Vise opts to use automated deburring with abrasive disc brushes, in place of grinding.

In use at Orange Vise is a Mori Seiki NHX4000 high-speed horizontal machining center.

As with most CNC machining centers, the deburring process typically requires taking parts offline and hand-finishing them using a variety of abrasive tools. Sun not only wanted to automate the finishing process, but also eliminate the messy grinding process the company had been using to achieve a specific surface finish.

Milling Cutters Not in the Picture

Orange Vise builds its vises with a cast-iron body, with selectively hardened surfaces as high as 50 to 60 Rc. That requires grinding, as milling cutters would wear out too quickly. Out of necessity, Orange Vise also would grind noncritical unhardened surfaces to create a uniform appearance over the entire body.

“This process involved removing, cleaning and then repositioning parts several times,” says Sun, “in order to grind each face. That process proved time intensive, particularly for the work that was purely cosmetic.”

To the rescue came a new line of abrasive disc brushes (NamPower, from Brush Research Manufacturing Los Angeles, CA), designed to allow CNC operators to automate the deburring process while delivering an ideal surface finish in the same operation.

“We started using the brushes for deburring, but quickly discovered they also provided a really nice surface finish,” says Sun.

Composed of flexible abrasive-nylon filaments bonded to a fiber-reinforced thermoplastic base, the abrasive-disc brushes contain a unique combination of ceramic and silicon-carbide abrasive. These abrasive filaments work like flexible files, conforming to part contours, wiping and filing across part edges and surfaces to deliver optimum burr-removal rates along with the desired surface finish. Other common uses are edge blending, part cleaning and rust removal. The ceramic abrasive tackles material removal, but tends to cut a bit coarse. The silicon carbide acts as a buffer to the cutting action. The result is deburring and finishing in a single operation. The brushes work well with nonferrous materials, as well as cast iron, mild steel and ductile iron, stainless and alloy steels, titanium and high-nickel alloys.

General Purpose or High Density?

Sun’s first decision was between the brush’s two available fill configurations: the Dot style, recommended for general-purpose deburring and surface finishing; and the Turbine style, which has a higher-density fill for more aggressive deburring.

The unique combination of automated deburring and surface finishing eliminates several time-consuming and laborious processes at Orange Vise.

To achieve the smoothest finish possible and approximate the ground surfaces of the CNC vise, Sun selected the Dot-style brush and intentionally reduced spindle speed.

“The surface finish was good enough that we actually were blending it with our ground finishes,” says Sun. “With large surfaces that required multiple passes, there are no visible blends. The whole part looks like it is done in one pass. Needless to say, the brushes speed up the process quite a bit.”

Broader Use than Originally Expected

Orange Vise has found the Dot-style NamPower brush to be flexible enough to conform to features of varying heights, proving useful on other parts manufactured at the company.

“We’re finding more and more uses for them,” says Sun. “We use the same brushes for aluminum, steel, cast iron and several other materials without having to swap them out very often.”

One such application, and one of its primary purposes, is for edge blending. According to Sun, Orange Vise uses a variety of deburring tools, including a 45-deg. chamfer. Although the tool doesn’t typically leave a burr, when it begins to wear burrs can crop up. That possibility previously required an Orange Vise employee to inspect each part and remove any burrs by hand. Now the company automatically deburrs chamfered holes and edges using the NamPower brush.

In addition, Sun says Orange Vise performs engraving on the vice jaws using a ball-end mill. Although the engraving on the underside of the vice doesn’t require deburring, it specifies finer engraving on the top surface. For this operation it employs a 45-deg. V-bit, which can create burrs. To the rescue—again: the NamPower brush.

“Grinding would be so much more work,” says Sun. “With the brushes it really doesn’t take any extra effort at all. It adds maybe 30 sec. to the process.” MF

Article provided by Brush Research Mfg. Co., Inc., Los Angeles, CA: 323/261-2193; www.brushresearch.com

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