Page 15 - Industrial_Technology_EXTRA_1st_June_2020_Classical

brake, or compensator, is a device connected to the Welding. This led him to reach out to a local tooling
barrel of a rifle or pistol to help control recoil and representative from Bass Tool & Supply, a leading
the rising of the barrel that normally occurs after supplier of CNC machine tools, for wheel brush
firing. options to remove the burrs in one automated
There are different forms of muzzle brakes, but operation. The rep, in turn, suggested he contact
most consist of a small length of tubing Los Angeles-based Brush Research Manufacturing.
approximately 5-centimeters long. Muzzle brakes The company is known for inventing the Flex-
utilize slots, vents, holes, baffles and similar devices Hone®, a tool characterized by abrasive globules
to redirect a portion of propellant gases to counter that are permanently mounted to flexible filaments
recoil and unwanted muzzle rise. Where and how that are attached to a center shaft. With its low-
these holes are placed in the muzzle brake has a pressure, low-temperature abrading process, the
tremendous effect on the influence of the brake in Flex-Hone tool can remove work-hardened layers
terms of recoil and muzzle movement. and deburr parts without disturbing the underlying
However, when machining these holes, large metallurgical structure.
burrs were forming at the oval-shaped gas ports. However, Brush Research also manufactures a
The cylinder was made of 4140 steel, which is a wide array of wheel, cup and end brushes in a
1% chromium – molybdenum steel alloy that is variety of sizes, filaments and grits.
generally hardened and tempered to a tensile Still, based on the geometry, location of the
strength of 850-1000 Mpa. burrs and the hardness of the metal alloy, it wasn’t
The company was machining the part on a immediately clear what the best solution would be.
5-axis machine in an elliptical path, which So, the engineers at Brush Research suggested
increased the size of the burrs created. “The burrs Mawazeb send in several sample parts for testing in
that were created were razor sharp and thicker than the lab. At its surface finishing laboratory in Los
we wanted them to be on each of the 4 main ports Angeles, Brush Research engineers analyze
in the part,” says James Mawazeb, Director of customer parts that require finishing, then selects
operations and lead engineer at JR Precision & and tests the tools that will provide the best solution
according to customer operating parameters.
At first, the company attempted to remove
the large burrs using NamPower
abrasive disc brushes.
Composed of flexible
abrasive nylon filaments
bonded to a fiber
reinforced thermo-
plastic base, the
disc brushes
contain a unique
combination of both
ceramic and silicon
carbide abrasive. The
abrasive filaments work like

June 2020 • INDUSTRIAL TECHNOLOGY EXTRA! • p15