The Only Deburring & Finishing Tool You Need
Delta Machine, recognized as one of the best precision machine shops for 2021, has relied on the Flex-Hone tool from Brush Research Manufacturingfor the past decade, allowing them to take care of complex parts in-house, at less cost.
by Jeff Elliot
Delta Machine Company, LLC, a machine shop specializing in com- plex, tight tolerance parts made of titanium, nickel alloys, stainlesssteel, aluminum, plastics, and other exotic alloys, was just selected for the 10 Best PrecisionMachine Shops for 2021 by a leading industrytrade magazine. Janos Garaczi, the company’spresident, still runs manufacturing to ensurethat everything is working well. He is in aunique position, having started with the company as a machinist and eventually workinghis way to president and owner. As such, heremains responsible for much of the programming, set-ups, and purchasing.
In the past decade, the machine shop hasrelied on a flexible honing tool for a widerange of automated CNC machining applications such as cross hole deburring, cylindrical honing, surface finishing, edge-blending,and cleaning. By integrating flexible hones inthe machining process, complex parts withcross-drilled holes and other difficult-to-access features can be deburred, honed, surfacefinished, etc. in-house, at less cost.
In automated machining, removal of burrsand sharp edges in cross-drilled holes andother difficult-to-access areas such as undercuts, grooves, slots or internal holes can betedious and time-consuming. One particular challenge is deburring the intersection ofcross-drilled holes frequently found in engineand transmission components.
Despite the challenges, the removal of burrsfrom the production process is an absolutemust for high-quality, precision parts. In manyapplications, cross-drilled holes act as conduitsfor fluids, lubricants, and gases. Failing to remove burrs can cause blockage of these criticalpassages or create turbulence in the flow. Burrscan also lead to part misalignments, affect dimensional tolerances, and limit the overall efficiency of machined components.
According to Garaczi, the tool he has se-
lected for such applications is the Flex-Hone
from Los Angeles-based Brush Research
Manufacturing (BRM). Characterized by the
small, abrasive globules that are permanently
mounted to flexible filaments, the product is
a flexible, low-cost tool used for sophisticated
cross hole deburring, honing, surfacing, and
edge-blending. The hones are available in a va-
riety of abrasive types, sizes, and grit selections.
“For deburring holes and honing whenwe need to clean up a component, it is theeasiest tool to use for us. There is a large variety of grades and sizes and it is very versatile,” says Garaczi.
“In terms of accessibility, I haven’t found
any other tools that can do what a Flex-Hone
can, whether for multiple cross holes or inter-
nal grooves, says Garaczi. “There is really no
way to effectively reach those areas with any
sort of other tool.”
For best results, the deburring tool is typ-
ically rotated into the main bore into which
the cross holes break. After a few clockwise
strokes, the tool is removed and the spindle
reversed to rotate and stroke the flexible hone
in a counterclockwise direction for a few more
strokes. The forward and reverse rotation cre-
ates a symmetrical deburring pattern. Coolant
should be used to keep metal cuttings and de-
burred metal in suspension.
According to Garaczi, removing burrs canbe particularly problematic when dealing withmachined superalloys, such as titanium, Monel, Inconel, Incoloy, Invar, Rene, and Hastel-loy, which are some of the most difficult materials to machine.
“Even during ‘grooving,’ if you cut the ma-
terial from one side, it just pushes the burr to
the edge; and if you approach it from the oth-
er side, it just pushes it back. It doesn’t want
to break off the material cleanly. As soon as
the tool gets a bit dull it gets a lot worse. So,
sharp tools with the right geometry are key,”
According to Garaczi, when deburring superalloys such as titanium or 13-8 stainless alloy, using the Flex-Hone has been very helpful.“Most of the 13-8 we machine is heat-treated,so it is subject to significant burrs. The honeis ideal for removing even the most stubbornburrs,” says Garaczi.
Garaczi points out that he is installing theflexible hones into CNC equipment to automate the process and reduce the time requiredto finish superalloys and stainless steels.
Despite the fact that these are abrasivetools, Garaczi says that even though “abrasives” are often all lumped into the same
category, a distinction must be made between abrasives used for aggressive material removal and abrasive finishing tools.Finishing tools release little to no abrasivegrit during use, and the amount generatedis comparable to the metal chips, grindingdust, and tool abrasion created during themachining process itself.
Even if minimal fine solids are produced,the filtration requirements for abrasive toolsare not much different than for machining.
Any particulate can be easily removed using
inexpensive bag or cartridge filtration systems.
“When you use the Flex-Hone for deburr-
ing, all you are doing is removing the burr.
It doesn’t create much dust,” adds Delta Ma-
chine’s Garaczi. “So, for me, any grit or dust
released is zero concern. It is not like we are
grinding inside the machine with powder
everywhere—this is not the same at all.”
“There are definitely scenarios where it
would be good to be able to perform surface
finishing of this type of material on CNCs,”
says Garaczi. “It would really save a lot of
time and extra processing cost.”
According to Garaczi, the use of the hone
is even helping his company cope with the
demands placed on it by Covid- 19, by ac-
commodating more work being done in an
automated manner. This not only requires
less labor but also facilitates social distancing
for any workers on the production floor. “I
want to do everything on the CNC machines
whenever I can, especially now,” he says.
To achieve this, the machine shop incorporates Flex-Hones in a variety of sizes in itstool carousels.
“For a part, we might use two to three dif-
ferent size hones, depending on the number
of cross port intersections and different hole
sizes,” says Garaczi. “However, it is really
easy to put a Flex-Hone in a toolholder, give
it a simple toolpath cycle and let it run.”
“It is difficult for a person to reliably re-
peat such work to the level of the required
quality. Automating this with the CNC ma-
chine usually will produce more consistent
results, while enabling greater social dis-
tancing among our staff on the production
floor,” concludes Garaczi.
For more, visit newequiment.com/21155308
Flex-Hone automated setup for cross hole deburring. Photo courtesy of Brush Research Manufacturing