WHITEHURST ENTERPRISES
Inexpensive, Accurate CNC Machine Helps
Start Production Woodworking Business
An inexpensive but highly
accurate and productive computerized numerical control (CNC) machine
has helped a CNC programmer start a successful new production
woodworking business. Brian Whitehurst previously worked for a
reseller of leading high-end CNC programming software, helping
customers solve difficult programming challenges. Then
Whitehurst saw a market opportunity and decided to go off on his own,
producing complicated architectural ornamentation that was up till now
mostly made by skilled craftsmen working with power tools. Whitehurst
has carved out a substantial market niche by producing decorative wood
carvings much faster and at higher levels of accuracy on CNC machines.
"CNC machining is taking the architectural ornamentation industry
by storm by producing a better product at a lower price,"
Whitehurst said. "The key is the availability of low cost CNC
machines that can accurately duplicate a computer aided design program
in much less time than someone working by hand."
In
his previous job, Whitehurst was a senior applications engineer
representing Delcam, a leading international CAD/CAM software supplier
to the mold, tool and die sector. His job was to work with
manufacturing businesses that were having difficulty producing
complicated parts, determine a software solution that would meet their
needs and train their people in how to use it. When very difficult
problems arose, Whitehurst would go in and write the CNC program
himself. He enjoyed working for an industry leader but felt the urge
to start a business of his own. He looked for an industry where he
could apply his considerable programming skills. Even though the
majority of his experience was in the metalworking industry, he was
drawn to woodworking because so many companies in that business were
using still using power tools to produce the increasingly complex
parts being demanded by the architectural market. Another attraction
of this industry is that woodworking machinery is much less expensive
than metalworking machinery because it doesn’t have to be built to
withstand the high forces often generated in cutting metal.
Better quality at lower prices
"I was confident that I could provide far better quality and
lower prices by using a CNC machine to compete with companies and
individuals that were producing carvings by hand," Whitehurst
said. Producing complicated pieces such as carved moldings and friezes
is a very slow process by hand. The job of producing the first piece
is typically assigned to a very experienced and highly paid craftsman
who cuts it out with hand and power tools. Then less experienced
workers typically duplicate the piece using a tracer. One problem with
this approach is that even the most skilled woodworker has difficulty
accurately producing three-dimensional contours. The result is a piece
that requires extensive finishing by hand, to chisel and sand the
piece the way a customer wants it.
"The beauty of a CNC machine is that you can define every detail
of the piece to absolute perfection in your CAD/CAM software and then
do something else while the machine produces the part,"
Whitehurst said. "While the CNC machine isn’t perfect, the
accuracy of the better machines is far, far beyond what can be
achieved by hand. And every piece that you make will be just as good
as the first one, such that each piece coming off will need little
hand finishing. While programming is a labor-intensive process akin to
cutting out the first piece by hand, once it is completed other pieces
can be produced without the attention of a person except for loading
raw wood and unloading finished pieces on the machine and occasionally
checking to be sure the tool hasn’t worn out or broken. The result
is that architectural ornamentation can be produced at a much more
competitive price on CNC machines."
The first critical decision facing Whitehurst as he began operations
was which CNC machine to purchase. He was aware that a new class of
machines that has appeared over the last several years is far less
expensive than machines designed for metalworking yet offers similar
accuracy on wood and plastics. After
studying these machines, he selected the Techno model 210 PC-driven
CNC wood router from Techno Inc., New Hyde Park, New York. This
machine, which sells for about $30,000 complete, is designed for
production routing and drilling on a wide variety of materials
including wood, plastic, MDF, solid surfacing materials, and
nonferrous metals. "I liked the Techno machine from the start
because it is flexible and easy to use. As I learned more I discovered
that it’s also very adaptable to nearly any woodworking problem.
For example, long pieces of molding can be stacked side by side while
the spindle traverses each piece to cut the pattern. On the other
hand, multi-sided pieces like a corbel, can be mounted on a rotary
table that moves the appropriate face towards the spindle one after
another. Best of all, the machine only costs about the same as my car
payment every month."
The Techno machine is
constructed on steel stress-relieved bases with hardened steel linear
ways. Its shaft-and-bearing system produces very smooth, play-free
motion and is an extremely rigid system that produces high-quality
cuts. The machine also uses anti-backlash ball screws. 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. The balls crews also make it
possible to produce wooden parts to the machine resolution of 0.0005
inch. Instead of being ball screw-driven, the less expensive machines
use rack and pinion gearing, which has too much play to make accurate
cuts in small areas. Also this type of gearing wears out quickly in
the dusty environment of a carpentry shop. The
other main difference we found between the Techno machine and the
others was that the Techno uses a servo motor to control cutting
motion while other machines use stepper motors, which can give a
stair-step cutting effect.
Producing anything that customers ask for
"With this setup, I have found that I can produce just about
anything that customers ask for," Whitehurst said. "For
example, one customer asked for a molding that looks like a grapevine
with the grapes protruding in 3D. They gave me a picture of what they
wanted which I scanned and then turned into a 3D model. To transform
the 2D image into a true 3D relief with a hand-carved look works this
way. The artwork is colored by the use of brushes and flood fill tools
and each color is assigned to an individual 3D shape profile. The
different types of profiles that can be generated include plane, round
and angular. The parameters of these profiles are controlled by
defining the basic shape, start height, limit height and wall angle,
giving almost total control over a wide range of 3D effects. The
program builds 3D relief’s by assigning a height to each pixel in
the 2D image. I provided my own artistic interpretation and also
designed the molding in such a way that it can be machined quickly. I
cut a sample piece in MDF, give it to the customer, and listen to
their feedback and then modify the program so that the finished pieces
are exactly what they want. If the customer ever needs more molding, I
can simply call up the program again and match the original order to a
tee."
"Another
interesting piece that I made recently is called a corbel – a
triangular decorative bracket that fits in the corner between a
ceiling and wall," Whitehurst said. "The program takes a
solid block of wood and whittles it down to an intricate 3D design on
three sides. The complexity was so great that I didn’t get it
exactly right the first time but as nearly always, I cut sample parts
in inexpensive wood and then measured the errors and used them as an
offset to correct the program." Whitehurst said that his new
business has also spawned several offshoots. While he is building his
production machining business, he also acts as a consultant to other
woodworking companies that want to establish a 3D machining capability
and provides custom programming services. "The
Techno machine is intelligently designed so that I can plug my own
devices into the various ports and provide commands in the program to
turn on a dust collector and an air blast to clean the tool," he
commented. "I also have a digital video camera pointing at
the machine so I can log in while I am visiting a customer’s site to
see how everything is going. In the future, I plan to add a tool
breakage sensor that will send me a page or an email when a tool
breaks in order to provide for fully unattended operation."
For more information contact: Techno, Inc., 2101 Jericho
Turnpike, New Hyde Park, NY 11040.
Phone: 516-328-3970 Fax: 516-358-2576 E-mail: TECHNO
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