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By Jeff Wolf
A computer numeric controlled (CNC)
router has allowed our company, National Sign and Design Group, to
expand into furniture, counter tops, trade show displays, and other
new sources of revenue, paying for itself within twelve months of
operation. For example, we more than doubled our income when a
restaurant that needed a sign also hired us to produce its counter
tops and sneeze guard. We now bid on higher-margin jobs that require
close tolerances, using the CNC router to achieve levels of accuracy
and repeatability that are impossible by hand.
National Sign started out as a home-
based screen printing business. We eventually expanded into vinyl
graphics, a process in which letters that have been designed on a
computer are cut from vinyl using a special plotter and then applied
to a plywood substrate. When we got requests for wooden signs with
dimensional cutouts, the work was contracted out to a company with a
router. Over the years, however, the demand for this type of work
kept growing while the quality and the dependability of the outside
contractor was becoming a problem. This led us to consider buying
our own router, specifically one that was computer-controlled so it
could be programmed to cut computer- generated letters and other
designs.
We identified accuracy, repeatability,
resolution, and reliability as the most important selection criteria
for the router. Some CNC routers we evaluated had components such as
rack-and-pinion drives that needed frequent maintenance and other
items that needed constant adjustment. We wanted to avoid these
sorts of chores and concentrate on our business. Price was also a
consideration. Some machines on the market at the time were priced
in the $80,000 range, and they were ruled out as too expensive for
our current volume of router work.
The search for a CNC router eventually
led us to Techno, Inc. CNC Routers, New Hyde Park, NY. The Techno
machines are designed for production routing and drilling on a wide
variety of materials including wood, plastic, MDF, solid surfacing
materials, and nonferrous metals.
The accuracy level of the Techno machine
was actually higher than we needed for sign making. It featured a
positioning accuracy of ±1 mm in 300 mm. We realized, however, that
the ability to produce parts with tight tolerances could lead to new
types of work. We also believed, after reviewing the specifications
of the Techno machine that it would be as reliable as we needed. Its
use of anti backlash ball screws, for example, would ensure
play-free motion. These screws have excellent power transmission due
to the rolling-ball contact between the nut and screws. This type of
contact ensures low friction, low wear, and long life.
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We didn’t find any other CNC router with
the combination of capabilities and accuracy level as the Techno
machine, unless they were quite a bit higher in price. The Techno
system we selected cost the same as less accurate machines yet
delivered the accuracy of higher-end machines.
With the purchase of the router, we
moved National Sign out of the house and into a 5,000-square foot
shop. Even employees with minimal computer experience were able to
use the driver software and run the machine. We initially used its
CNC routing capabilities to do standard signage jobs for its
existing clients and to take on contract work for other sign makers.
The machine gave us the ability to produce fancier signs such as
those with reliefs cut out of cedar planks. It also gave us an
aesthetic advantage in the production of wooden signs with
dimensional letters raised an inch or more. With most routers, it
isn’t possible to cut this deep with a very thin tool in one pass.
An inch-thick letter, for example, would typically be cut with a
1/4-inch ball end mill. This tool would cut 1/4-inch deep on each
pass, requiring four passes to complete the one-inch letter.
Ideally, each pass would be cut identically to the others but with
most machines, the repeatability is not high enough to permit this.
This results in distinct ridges in the letter from the four
different passes. The sign must be hand finished to remove the
ridges. Due to the Techno machine’s repeatability of 0.004 inch, we
have found it unnecessary to do any hand finishing on this type of
sign because this router doesn’t leave any ridges.
New Types of Work
Although the sign business was expanding
due to the Techno machine, it wasn’t long before we were using it to
do jobs that weren’t related to signs at all. For example, what
started out as a regular sign job turned out to include a
substantial amount of carpentry. We had been hired to make a sign
for a new juice store and while we were discussing the job with the
owner, he happened to mention that he was having trouble getting
contractors to build his counter tops and the acrylic sneeze guard
above the juice preparation area. Knowing that the router could cut
these materials, we offered to do that work for him as well.
The sneeze guard was designed on the
computer to match the store’s display case. It was angled so that as
it comes up from counter it leans away from the customer at about a
75- degree angle. At the top is a horizontal, 12-inch shelf that is
used for displays. Our designer added some shelves on the kitchen
side of the sneeze guard for rigidity.
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The whole unit needed to fit precisely
onto the counter with a margin of one-quarter inch. After modeling
the entire sneeze guard on the computer, the designer broke down the
design into nine separate parts. He sent the files to the router,
which cut all of them from a large sheet of 1/4 inch acrylic in
about 20 minutes. Because the router cut so cleanly, no sanding was
required. The pieces were assembled and the sneeze guard was ready
in just a few hours. The counter tops were produced in a similar
manner. They were designed on the computer to include holes for
holding cups. The pieces were cut with the router and assembled. We
also laminated the counter tops, using the router to cut the pieces
of laminate as well. When the counter tops were installed in the
store, they fit perfectly and the owner remarked that they looked
better than other counters that had been built by carpenters. This
project started out as just a sign job, for which we were charging
$1,000. We ended up making more than twice that amount, pulling in
an additional $1,500 for the sneeze guard and countertops. The
success of that job opened up other options for our company. Mostly
by word of mouth, the area learned of our new capabilities, and we
have started producing trade show exhibits with the router as well.
We have also been asked to help a local manufacturer of wooden
rocking horses. He was producing one horse every three weeks by
hand.We use the router to cut each piece from flat stock 2 inches
thick, routing out the curved surfaces of a leg, for example, across
180 degrees, then turning it over and cutting the other side. Using
this technique, we can produce six horses in the time it takes to
make one by hand.
With all the additional work that the
router is bringing in, the machine will probably pay for itself in
the first twelve months. We may eventually purchase another one.
Currently, our company runs the router between four and six hours
per day. But we have recently bid on jobs that never would have been
considered before getting the router. A good example is the
production of templates for a company that makes molds for
automobile seat cushions. Each seat requires hundreds of templates
that must be accurate to within thousandths of an inch. That is now
within our capabilities. If we win some of the jobs we have bid on
lately, the router may be used as much as 12 hours a day. We will
then purchase a second machine if the volume of router work grows
further.
Jeff Wolf is the president of National
Sign and Design Group in Brampton, Ontario.
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