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Started in
1969, Filtertech custom designs and fabricates liquid
filtration systems for coolants and lubricant used in a
variety of industrial settings, most notable among these are
manufacturers who draw copper and aluminum wire products,
along with systems for steel mills and automotive component
processing. And, as indicative of the industries served, the
firm's filtration systems are large. According to Plant
Foreman, John Brown-Paul, Filtertech produces systems which
may be equipped with cylindrical tanks, or in many cases
what is referred to as "flat bed" units. The flat bed
systems typically fall within a range of 8 to 70 feet long
and are complete with pumping mechanisms, filtration media
(usually a paper-type filter, automatically indexed to
present clean surfaces), and conveyor for transport of
sludge and contaminate particles to collection containers.
With respect
to the fabrication of the flat bed filtration systems, Mr.
Brown-Paul says is what prompted the company to seek a more
efficient holemaking technology. The conveyor of a flat bed
unit is mounted to the filter housing using a series of
bolts placed every 5" for strength and stability on both
sides of the conveyor throughout its length. For the longer
systems, this could mean well over 300 holes have to be
drilled. The size of the fabrication components such as the
mounting rails are too large and awkward which precluded
taking them to stationary machine tools. The holes, ranging
from 5/8" to 13/16" diameter drilled through I-beams and
channel materials up to 3/4" thick, depending upon the
system design, had to be drilled using hand held electric
drills and twist drill bits.
Mr. Brown-Paul
reports that the most effective way to drill the holes in
the past was to use three steps -- a pilot hole, an
intermediate size drill, then the finish size tool. Add to
this a secondary operation to remove the jagged burr and
each hole could easily take 10 to 15 minutes for completion.
He also mentions that operator fatigue created by holding
and pushing the hand held drill played a role in slowing
down production as well as greater care being required
trying to maintain the roundness and alignment of the holes.
With the
increase in orders and production times running long, Mr.
Brown-Paul decided to try the Rotabroach Model 10904
magnetic drill and annular cutters from Hougen. Within
drilling just a few holes with the magnetic drill and
cutters, it was apparent to Mr. Brown-Paul that he had found
the right solution. "Overall, we're probably saving 40 to
60% of the time we used to spend drilling the holes," he
says. "There's little fatigue factor now, the holes are
round and always in the right alignment with no drill wander
as twist drills are prone to do. And, for most applications,
we no longer have to deburr the holes because of the
cutters' smooth cutting action."
These results
experienced by Filtertech are attributable to the magnetic
drill and cutter combination. First, the Model 10904
magnetic drill is light and compact, weighing just 28 pounds
and measuring 16-7/16" x 7-3/16" x 8-1/4". Its drilling
capacity is 1-3/8" hole diameter through materials up to 2"
thick. A powerful electromagnetic base provides a dead lift
hold strength of over 1700 pounds on average while rear
mounted, accessible controls and a side-to-side reversible
feed handle configuration enhance the unit's ergonomics.
The Model
10904 also incorporates Hougen's exclusive safety features
to insure a safe work environment. These include a motion
sensor which shuts down the drill motor if shift or lift of
the magnetic base is detected. A two stage power on switch
prevents the drill rotation unless the magnet has first been
engaged, and, in the case of a power interruption, safety
circuitry will keep the drill motor off after power is
restored until the start button is manually depressed.
The Rotabroach
"12,000-Series" Annular Cutters and their alternative
cutting design were the other contributor to the improved
drilling times. One of the reasons twist drills present
drilling problems is that the tools have a center point. It
is this point on the drill that is often referred to as the
"dead zone" because very little if any cutting action takes
place. The reason? As the diameter of the drill approaches
zero at the center point, the surface cutting speed, being
the product of spindle revolutions x diameter, also drops
off to near zero. The dramatic drop in SFM correlates into
additional thrust being required, a leading cause of tired
arms, hands and general fatigue.
Annular
cutters, on the other hand, offer an important design
difference from the traditional twist drill bit. Annular
(meaning shaped like a ring) cutters like the
"12,000-Series" Rotabroach cutters are hollow so there is no
center point or "dead zone" to contend with. All of the
cutting edges are at the periphery of the tool, thus SFM is
virtually constant -- there is no pushing or thrusting of a
non-cutting point through the material.
Because the
annular cutters are hollow, this also means that less of the
stock is being converted into chips. As the Rotabroach
Cutter cuts around the hole, the center portion remains a
solid core, and once the cut is complete, is ejected from
the tool as a slug of material.
Another
important difference between a Rotabroach Annular Cutter and
a twist drill is the number of cutting edges. Typical twist
drills have two flutes which tend to form the long string
chips. The annular cutters, however, can have up to 12
cutting edges to more evenly distribute cutting forces for
longer tool life and better surface finishes within the
hole. What's more, the patented Hougen-Edge tooth geometry
incorporated into the Rotabroach design has been field
proven to provide a rounder hole than can be achieved with
twist drills and produces virtually no burr on the
breakthrough side of the stock, so secondary deburring and
chamfering operations can be eliminated.
To Filtertech
and Mr. Brown-Paul, the combined improvements in drill
operation and cutter performance have made the difference to
the company's productivity and quality -- and they're now
using the Rotabroach Magnetic Drill and cutters throughout
their operations, continually finding new applications and
faster drilling times. |
