Sites: | GlobalSpec Electronics | CR4 | Electronics360
Login | Register
The Engineer's Place for News and Discussion®

BRM's Flexible Honing, Surface Finishing, and Deburring Blog

BRM's Flexible Honing, Surface Finishing, and Deburring Blog is the place for conversation and discussion about how to solve difficult finishing problems. For over 50 years, Brush Research Manufacturing (BRM) has helped customers use brushing technology to clean, rebuild, and resurface components ranging from engine cylinders to brake rotors to flywheels to firearms. BRM's Blog on CR4 provides real-world examples of how flex hones and wire brushes work. It also evaluates related technologies and invites questions from the community.

How to Automate Surface Finishing and Deburring

Posted August 19, 2014 7:11 AM by Brush Research

Brush Research Manufacturing (BRM) supplies a complete line of surface finishing solutions for inner diameter (ID) and outer diameter (OD) applications. For ID surface improvement and burr removal, BRM's Flex-Hone® tool is the industry standard. For OD applications, BRM solutions include NamPower technology, a family of high-performance nylon abrasive brushes.

Flex-Hone® Tools for ID Applications

BRM Flex-Hone® tools are flexible, resilient honing tools that remove burrs and improve the surface finish of cylinder walls. They feature abrasive globules laminated to flexible nylon filaments, and are manufactured in 10 different abrasive types and 11 grit options. Self-centering, self-aligning to the bore, and self-compensating for wear, BRM ball hones come in standard sizes from 4 mm to 36".

The Flex-Hone® is a low RPM tool that's suitable for most any rotating spindle. Examples include drill presses, milling machines, lathes, CNC equipment, robotic arms, and machine centers. Built with a double-wire metal stem, ball hones are secured in a chuck, collet, or similar holding device. With CNC equipment and machining centers, use a Jacobs style chuck or CAT 40 collet.

Flexible cylinder honing's low-pressure, low-temperature abrasive process is ideal for a wide variety of finish requirements. Flex-Hone® tools are not designed for heavy-duty or high-precision metal removal, however. Instead, manufacturers use flexible cylinder hones to reduce surface roughness, and improve surface finish down to the single RA level.

Flexible honing imparts a substantially flat or plateau finish with a uniform pattern of oil-retaining grooves for optimum lubrication. Flex-Hone® tools also remove cut, torn, folded, and jagged metal that can affect dimensional tolerances, cause part misalignments, and limit the overall efficiency of machined components. Flexible cylinder honing also blends-in radius ports and deburrs cross-drilled holes.

For more information, download the Flex-Hone® Resource Guide and watch the Flex-Hone® In-Machine Setup for Surface Finishing and Deburring video.

NamPower Technology for OD Applications

BRM NamPower technology includes abrasive disc brushes, abrasive hex-drive tools, composite hub wheel brushes, and accessories such as lightweight tool holders that provide vibration damping and flow-through cooling. Like Flex-Hone® tools, NamPower nylon abrasive brushes can be used with automated machinery, CNC machining centers, transfer lines, and robotic cells.

NamPower brushes feature flexible, abrasive nylon filament that enable manufactures to deburr, edge radius, and surface finish the outer diameter (OD) of parts. Additional applications include cleaning and surface preparation. With their balanced construction and high-quality components, NamPower brushes combine a cost-effective design with dependable, high-performance results.

NamPower abrasive disc brushes come in two types: dot for light deburring and general-purpose use, and turbine for medium and heavy-duty deburing. NamPower abrasive hex-drive tools are designed for semi-automatic and fully automatic machinery, including NC, CNC, and robotic machine tools. Their unique Hex-Drive System allows these brushing tools to turn in both directions for 360° finishing.

NamPower composite hub wheel brushes feature indestructible cores and silicon carbide or diamond abrasive filaments. Silicon carbide is ideal for deburring and edge radiusing most metals. Diamond filaments are recommended for harder materials such as ceramic, glass, carbide, and hardened tool steels. NamPower nylon abrasive can be used under wet or dry conditions.

For more information, download the NamPower Resource Guide and watch the How to Automate Deburring and Surface Finishing - NamPower Abrasive Disc Brushes video.

Visit BRM at IMTS 2014 (Booth N-7163)

Do your tradeshow plans include a visit to the International Manufacturing Technology Show (IMTS) next month? From September 8 to 13, BRM will be in Booth N-7163 at McCormick Place in Chicago. Meet with our technical specialists at IMTS 2014 and find solutions to your surface finishing challenges. For more information, contact us.

Author's Note: This CR4 blog entry originally appeared in the BRM Flex-Hone Blog.

Add a comment

Diamond and Silicon Carbide Abrasives for Nylon Abrasive Wheel Brushes

Posted August 11, 2014 2:59 PM by Brush Research

Nylon abrasive brushing technology includes abrasive disc brushes, abrasive hex-drive tools, composite hub wheel brushes, and accessories such as tool holders and adapters. These high-quality, professional-grade products enable manufacturers to deburr, radius, and surface finish the outer diameter (OD) of metal parts. For removing sharp edges and creating a desired radius, manufacturing leaders in a variety of industries prefer NamPower wheel brushes.

As this YouTube video shows, NamPower nylon abrasive composite hub wheels feature indestructible cores, a balanced construction, a choice of face widths and diameters, and a uniform fill pattern. An alternative to wire wheels and non-woven abrasive brushing tools, NamPower wheel brushes are used in the production of turbine blades, steel gears, machine parts, extrusion cut-offs, and shaft finishing. These wheel-shaped abrasive nylon brushes can also produce an edge radius on cutting tool inserts.

Understanding Abrasive Types

Recently, BRM announced the addition of diamond-impregnated composite hub wheel brushes to its NamPower product line. The introduction of these long-lasting, cost-effective diamond wheels extends the capabilities of NamPower technology, and means that industrial buyers need to consider abrasive type during wheel brush selection. Other important specifications to consider include grit size, brush diameter, and face width.

Available with silicon carbide or diamond abrasive, NamPower wheel brushes solve surface finishing challenges. Choose silicon carbide for deburring and edge radiusing most metals. Choose diamond for harder materials such as ceramic, glass, carbide, and hardened tool steels. BRM's diamond abrasive wheel brushes are also ideal for producing edge radii on diamond and cubic boron nitride (CBN) surfaces. Their composite hub construction offers a dense, uniform fill pattern for more cutting points.

Diamond Wheel Brushes

NamPower diamond-filled composite hub wheel brushes are also great for polishing the flute relief on carbide and high speed drills, end mills, and reamers. These BRM brushing tools can produce an edge radius on carbide inserts, too. With end mills and reamers, a polished flute relief greatly enhances chip removal and promotes better finishes and longer tool life. With carbide inserts, an edge radius prevents fracturing and premature insert wear.

BRM's black diamond-filled composite wheel brushes are available in three diameters: 100-mm, 150-mm, and 200-mm. The 100-mm diameter brush is manufactured in a 5-mm face width to allow finishing of smaller sizes. The 150-mm and-200 mm brushing tools have either a 10-mm or 15-mm face thickness to accommodate a variety of flute relief requirements. All NamPower diamond wheels come standard in 600-grit, which offers the perfect combination of cutting power and ultra-smooth final finish. Other grit sizes are available by special order.

Silicon Carbide Wheel Brushes

NamPower wheel brushes that use silicon carbide (SC) abrasive are available in four different grit sizes: 80, 120, 180, and 320. Grit selection is highly dependent on the starting surface finish and the amount of material refinement that's required. During product selection, choose the coarsest grit possible that will still yield the required surface finish. The NamPower Resource Guide lists staring Ra values, a measure of roughness, for each available SC grit size.

Coarse grits are recommended for use on heavier burrs, or in applications where a fine surface finish is not required. Fine grit brush tools that are used on a rough starting finish will have less effect on surface condition improvement than the use of a coarse-grit brush followed by a finer-grit tool. In addition to cutting and finishing, grit size also affects radial brush flexibility. Industrial buyers should note, too, that NamPower nylon abrasive wheels with coarser grits have larger-diameter filaments.

Author's Note: This CR4 blog entry originally appeared in the BRM Flex-Hone Blog.

Add a comment

How to Use Flexible Honing Tools

Posted August 04, 2014 2:05 PM by Brush Research

Flexible honing tools are versatile. Supplied in standard sizes from 4-mm to 36", flexible cylinder hones are available in 8 different abrasive types, 11 different grit sizes, and are suitable for any type or size of cylinder. Brush Research Manufacturing (BRM) also offers custom Flex-Hone tools, as well as surface finishing solutions such as the Flex-Hone for Firearms. For inner diameter (ID) operations such as burr removal, edge blending, cylinder wall deglazing, and plateau finishing, flexible cylinder hones are ideal.

Choosing the right Flex-Hone tool for your application is essential, but it's important to follow proper guidelines for use. A ball hone's abrasive globules are its most distinctive features, but Flex-Hone tools also feature a metal stem for easy mounting and quick tool changes. Some users chuck the Flex-Hone tool in a handheld electric drill. Others mount flexible cylinder hones in production machinery. This versatility, along with the deburring tool's quality and reliability, add to the value of flexible honing.

Off-Line and In-Machine Operations

Flex-Hone tools can be used with a variety of garage, machine shop, and manufacturing equipment for off-line or in-machine operations. Typically, users already own the power tools or machinery that they'll need for cylinder honing. For example, most hobbyists own a hand drill and most manufacturers have machines with spindles. Amateur and professional gunsmiths, firearms and auto parts companies, diesel mechanics, engine tuners, and even light aircraft builders all use Flex-Hone tools.

As this How to Use a Flex-Hone Tool video shows, off-line operations occur away from production machinery, such as on an engine stand or workbench. By using a ball cylinder hone with an electric hand drill, for example, a Flex-Hone® customer can surface finish engine cylinders or the bores on shotguns, rifles, revolvers, pistols, or paintball guns. Rotate the flexible hone prior to entry, and remember that the BRM ball hone is a low RPM tool. The Flex-Hone Resource Guide provides general speed ranges.

Unlike off-line honing, in-machine deburring and surface finishing uses existing production equipment to automate operations. By using the Flex-Hone with existing production machinery, manufacturers can reduce labor costs, optimize machine cycle times, and promote surface finish uniformity. Designed for use with most any rotating spindle, automated surface finishing and deburring maximizes investments in milling machines, lathes, CNC equipment, robotic arms, and machining centers.

Lubrication and Clean-Up

With both off-line and in-machine operations, flexible honing tools always require lubrication. Choose a high-quality honing oil (such as BRM Flex-Hone oil) or other good-quality lubricant, such as machine oil. Never use solvents, as they may degrade the adhesive bonds in the tool. Don't skimp with a few drops of honing oil, but instead lubricate the Flex-Hone tool generously. Proper lubrication helps keep heat to a minimum, prevents the tool from loading, and suspends the abrasive material.

After flexible honing is complete, thoroughly clean the cylinder. For best results, use a soft nylon brush and hot or warm soapy water. Dry the bore and then clean with a lint-free cloth that's coated with a light oil or mineral spirits. Continue to clean the cylinder until the lint-free cloth remains clean. For more information, download the Flex-Hone Resource Guide and watch the Flex-Hone videos available on BRM's YouTube channel.

Author's Note: This CR4 blog entry originally appeared in BRM's Flex-Hone Blog.

Add a comment

How to Choose Cup Brushes

Posted July 28, 2014 3:09 PM by Brush Research

Cup brushes are surface finishing and deburring tools that feature a cup-like body to which filaments attach. A type of power brush, these rotary brushing tools have metal or nylon abrasive filaments and come in a variety of tool diameters. Cup brushes are designed for use with grinding tools, and have a 5/8"-11 arbor hole or integral shaft for connecting the industrial brush to powered equipment or even machinery.

For industrial buyers, choosing a cup brush requires an understanding of cup brush types and product specifications. Many different types of cup brushes are available, and filament type is an important consideration. Wire cups are best suited for burr removal and surface preparation on large surfaces. Nylon abrasive cups are ideal for light deburring, edge blending, and general surface finishing. Other applications for cup-style power brushes include rust, paint, and weld scale removal.

Wire Cup Brushes

When choosing wire brushes, buyers need to specify wire size, filament material, and wire style or type. Typically, wire sizes are given as decimal measurements. The larger the wire size and thickness, the more aggressive the brush. Stainless steel and carbon steel are common filament materials. Carbon steel is more aggressive than stainless steel, but can leave "after rust" on the workpiece surface. Stainless steel doesn't leave residues that can oxidize, but these wire brushes are less aggressive than carbon steel brushing tools.

In terms of wire style or type, buyers can also choose crimped or knotted wire brushes. Wire size and material are important, but wire style is critical to abrasiveness and aggressiveness. Crimping allows the metal filaments to better support each other than with straight bristles. Crimped brushing tools are more flexible than knot-style cup brushes, but crimped brushes are also less aggressive. For heavy-duty surface finishing and burr removal applications then, knotted wire brushes are recommended.

Single Row, Double Row, and Cable Twist

Knot-type cup brushes are available in single row, double row, and cable twist designs. Single-row, knot-type brush tools are used for the removal of burrs, weld scale, paint and rust, as well as edge blending and surface preparation. Double-row, knot-type cup brushes provide fast cutting and cleaning over wide areas. Both single-row and double-row power brushes feature filament ends that are loosely twisted and tufted for more flexibility.

By contrast, knot-type cup brushes with a cable twist have wide, tightly-twisted ends for more aggressive brushing. Applications for these cup-style industrial brushes include heavy-duty burr removal, surface preparation, and surface finishing. Like other types of wire cups, these surface finishing and deburring tools are available in different diameters and with an arbor hole for attachment to grinding tools and equipment.

Abrasive Nylon Cup Brushes

As a full-line supplier of surface finishing solutions, Brush Research Manufacturing (BRM) also provides cup brushes with abrasive nylon filaments. Cup brush nylon abrasive brushing tools are available with aluminum oxide and silicon carbide abrasives in a variety of grit sizes. Abrasive nylon cups are non-reactive, and provide an alternative to steel wire brushes for applications such as light deburring, edge blending, and general surface finishing.

Abrasive nylon cup brushes can be used in hand operations and with automated equipment, including CNC machinery. Available in different diameters, some of these power brushes feature a 5/8"-11 threaded arbor hole. Others have an integral shaft for use with handheld grinding tools and powered equipment. As with all power brushes, including wire cup brushes, maximum safe free speed (MSFS) in an important specification to consider. For more information about cup brushes, watch this short video.

Author's Note: This CR4 blog entry originally appeared in the BRM Flex-Hone® Blog.

Add a comment

Flexible Honing for Engines

Posted July 21, 2014 4:54 PM by Brush Research

Do you rebuild gasoline or diesel engines? How about engine components such as valves, connecting rods, or crankshafts? Whether you're a professional engine mechanic or a dedicated do-it-yourselfer, Brush Research Manufacturing (BRM) offers surface finishing solutions that are versatile, reliable, and easy-to-use. BRM Flex-Hone tools can be used with a handheld electric drill, and do not require special training, expensive equipment, or complex setups or clean-ups.

Engine Cylinders

Flexible honing tools improve surface finish and remove burrs at the same time. Designed for inner diameter (ID) applications, BRM's flexible cylinder hones are also known as ball hones because of their distinctive appearance. Made with abrasive globules that are permanently laminated to flexible nylon filaments, ball hones are self-centering, self-aligning to the bore, and self-compensating for wear. Always use these engine hones with a lubricant, preferably BRM's specially formulated Flex-Hone oil.

With its low-temperature, low-pressure abrading process, flexible honing produces a substantially flat surface that's free of jagged peaks and cut, torn, or folded metal. The plateau finish that the Flex-Hone imparts features a cross-hatch pattern of oil-retaining valleys for optimum lubrication. With used engine cylinders, BRM ball hones can be used to break the glaze-like finish that forms on cylinder walls. In this way, cylinder deglazing promotes proper lubrication along with piston ring seating and sealing.

BRM engine hones are ideal for cylinder wall surface finishing, but they're not designed for heavy-duty material removal. Rigid hones can impart an uneven or unidirectional crosshatch, but honing stones are recommended for initial honing, cylinder resizing, and geometry correction. When selecting honing tools for cylinder wall surface finishing then, use the BRM Flex-Hone to deglaze or surface finish the walls of cylinders that are not out-of-round or that require resizing.

Engine Components

As BRM's Flex-Hone Blog attests, professional and DIY mechanics alike are using flexible honing tools to deburr, deglaze, and surface finish engine cylinders. These aren't the only engine-related applications for Flex-Hone® technology, however, as BRM explains on the automotive industry page of its website. In addition to these on-line resources, MSB Tuning has documented its own experiences using flexible cylinder hones on engine components.

In Flex-Hone Applications for Engines, the engine tuner describes the successful surface finishing of main bearing tunnels, conrod big-end tunnels, OHC camshaft tunnels, valve guides, DOHL lifter bores, and in-block hydraulic lifter bores. The engine shop also notes "miscellaneous uses" such as with water pump tubing. "If there is a hole and I need to surface finish it," the author explains, "then I Flex-Hone it".

Available for any type or size cylinder, Flex-Hone tools come in a variety of abrasive types and grit sizes. For example, to surface finish a connecting rod, MSB Tuning used an 800-grit silicon carbide (SC) cylinder hone. To impart a very fine fish, the tuner talked about using aluminum oxide (AO) instead. For complete information about abrasive selection, tool selection, and ball hone use, download the Flex-Hone Resource Guide from the BRM website today.

Author's Note: This CR4 blog entry originally appeared in the BRM Flex-Hone Blog.

Add a comment

DIY Disc Brake Rotor Resurfacing

Posted July 14, 2014 1:05 PM by Brush Research

Do your disc brakes squeak or squeal? As DSPORT magazine explains in a new article, and as Brush Research Manufacturing (BRM) shows in a new YouTube video, you may want to look at your brake rotors. Brake pad glaze and surface corrosion are common causes of noisy disc brakes. Fortunately, there's a surface finishing solution that's as easy-to-use as a power drill. Trusted by professional and DIY brake mechanics alike, the Flex-Hone for Rotors is ideal for new and turned rotors.

Rotor Refurbishment

In Glaze is for Donuts: Do-It-Yourself Disc Brake Resurfacing, Jun Chen of DSPORT magazine explains why BRM's Flex-Hone for Rotors is the right tool for rotor refurbishment. For years, Flex-Hone users such as machine shops, manufacturers, and engine builders have been using flexible hones to improve the surface finish of cylinder walls. The Flex-Hone for Rotors is designed for flat surfaces instead, but uses BRM's Flex-Hone technology to impart a superior, non-directional surface finish.

As the "Quick Tech" article in DSPORT's August edition explains, some motorists blame vibrations while braking on warped rotors. Most modern rotors are made of iron, however, and are unlikely to warp because of this metal's hardness and stability. Typically then, brake vibration is caused an uneven layer of material that's transferred from the brake pad to the brake rotor. Improper pad bedding isn't the only cause of brake problems, however, as surface corrosion and improper machining may be to blame.

Brush Tool Selection and Use

Suitable for use with a handheld electric drill, the Flex-Hone for Rotors comes in coarse, medium, and fine grits. Coarse-grit brush tools remove heavy buildup and corrosion. They also remove sharp edges on rotor slots and cross-drilled holes that can contribute to rotor cracking. Medium-grit Flex-Hone for Rotors tools also remove layers of pad material, but impart a smoother surface. Fine-grit flexible rotor hones impart the finest finish of all, and may be used after coarse-grit and then medium-grit tools.

To test the Flex-Hone for Rotors under real-world conditions, DSPORT magazine acquired four brake rotors from a race car with some time at the track. Equipped with cordless drill and a coarse-grit brush tool, the crew removed the transfer layer from each rotor's face. The DIY mechanics then switched to a medium-grit tool, and finally to a fine-grit tool. Because the Flex-Hone for Rotors is self-leveling and applies uniform pressure, keeping the brush tool square and flat was an easy task.

Best Practices for Resurfacing Brake Rotors

"Be sure to have at least a 50-percent overlap between passes to ensure that no rough our untouched edges remain," author Jun Chen advised DSPORT readers. As BRM explains in its Flex-Hone for Rotors brochure, users should work in towards the center and then out to the edge, applying light pressure to the rotor's face. Rotate the tool between 300 and 600 RPM, and remember that dwell time - not excessive pressure - produces the desired finish.

BRM also advises Flex-Hone for Rotors users to hold the rotor in a brake lathe, and to spin the rotor between 125 and 210 RPM during honing. DSPORT magazine recognized that some DIY brake mechanics don't have a lathe, however, so its crew placed the brake rotors on a workbench. "This process will leave a finish very similar to a new rotor", the author explained before concluding that "the Flex-Hone for Rotors can help you save a few bucks and get rid of that annoying brake judder for good.

Flex-Hone for Rotors users to hold the rotor in a brake lathe, and to spin the rotor between 125 and 210 RPM during honing. DSPORT magazine recognized that some DIY brake mechanics don't have a lathe, however, so its crew placed the brake rotors on a workbench. "This process will leave a finish very similar to a new rotor", the author explained before concluding that "the Flex-Hone for Rotors can help you save a few bucks and get rid of that annoying brake judder for good.

Author's Note: This CR4 blog entry originally appeared in BRM's Flex-Hone Blog.

17 comments; last comment on 07/18/2014
View/add comments

Previous in Blog: Made in the USA Surface Finishing Solutions  
Show all Blog Entries in this Blog