Brush Research Manufacturing (BRM), Made in the USA maker of flexible honing tools and a full line of industrial brushes, is announcing user feedback about Flex-Hone® technology for aircraft building. In an article called Flexible Honing for Airplane Parts, the California company explains how a hobbyist used BRM ball hones to surface finish the inner diameter (ID) of aluminum spars on a Bede BD-4 light aircraft.

In fixed-wing aircraft like the BD-4, the spar is the wing’s main structural member. Metal ribs attach to the spar and help carry flight loads, as well as the weight of the wings while the aircraft is on the ground. In the case of the kit-built BD-4C airplane, tubular spars in the wings slide into and out of the fuselage’s center section. To ensure a proper fit, these spars need the right shape and dimensions.

Cylinder Honing for Aluminum Spars As BRM’s on-line article explains, Flex-Hone® toolsare not designed for heavy-duty material removal. The flexible cylinder hones are not built to correct part geometries either. Hobbyists sometimes use ball hones in non-conventional ways, however, and demonstrate how Flex-Hone® technology is versatile, reliable, and easy-to-use with any type or size cylinder.

With the BD-4C airplane, the tube-like spar has a 6.5-in. inner diameter (ID) and runs the entire length of the wing. As the hobbyist in BRM’s article discovered, however, the ends of this aluminum cylinder can be slightly oval-shaped instead of perfectly circular. By honing the cylinder walls with Flex-Hone® tools, the aircraft builder removed enough metal from the bore so that the spars could fit the fuselage.

How to Use Flexible Honing Tools As BRM’s new article explains, flexible cylinder honescan be mounted in handheld power tools such as electric drills. Built with a stiff, double-wire metal steam, the Flex-Hone® tool’s most distinctive feature is the abrasive balls or globules that are permanently laminated to flexible nylon filaments. The BRM ball hone’s low-temperature, low-pressure abrading process provides a soft cutting action.

Although the BD-4 aircraft builder honed the cylinder walls for longer than BRM recommends, the user’s overall experience is instructive. For example, by honing with a coarser-grit Flex-Hone® and then a finer-grit tool, the hobbyist achieved a smooth surface finish that facilitated part assembly. For more information, read Flexible Honing for Airplane Parts and download the Flex-Hone® Resource Guide.

About Brush Research Manufacturing

Brush Research Manufacturing (BRM), maker of flexible honing tools and nylon abrasive brushes, is located in Los Angeles, California. For 55 years, we’ve been solving difficult finishing problems with brushing technology. BRM’s Flex-Hone® tool is the standard against which all other cylinder hones are compared. For outer diameter (OD) deburring and surface finishing, choose NamPower brush tools.

Today, BRM is a full-line manufacturer of industrial brushes with an ISO 9001:2008 certification and a global network of distributors. Most of our products are made in the USA, and we proudly employee 75 workers here in Los Angeles. Through their hard work and commitment to quality, BRM now supplies hundreds of distributors across the U.S. and exports brush technologies to over 50 countries worldwide.