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When laser-based guidance
and control first appeared on the construction scene some 30 years
ago, it was a technology targeted toward big companies, big machines,
and big projects. Only contractors with the most massive airport
and highway contracts could justify a return on investment. But
today, the laser arena is a venue where small companies, small machines,
and small jobs are getting into the game. Laser technology is earning
its mass-market appeal. Systems are affordable with price points
hitting home runs in almost anyone’s budget ballpark. Yes,
there are still holdouts—those who feel that the technology
is too complicated, too hard to learn, and too costly to replace
the comfort level in hands-on staking and grade checking. However,
this too shall ultimately pass. The big benefits of lasers will
continue to increase, eventually outweighing any barriers to its
use.
Within the current market,
experts point to global positioning system (GPS) control as the
“it technology” for large-scale equipment and earthwork
operations, while the demand for cost-efficient laser systems is
seeing growth when applied to smaller machines such as skid-steers,
backhoes, and mini excavators.
Due to an ability to
easily upgrade from simple to more complex laser systems, many prospective
machine control market participants take a first step with laser
guidance as an introduction to full-out machine automation. “The
reason why laser tools are a great steppingstone for smaller contractors
is that the instrumentation can be used independent of machine control,”
says Harry Ward, executive vice president of Outsource Inc., a Virginia-based
CADD consulting firm. Projects conducive to using lasers without
machine automation, he says, include placing pads, performing formwork,
setting foundations or footings, achieving depth control for sub-base
excavation, and conducting finish grade work.
Ward cites three main
types of laser use in construction. The first is a simple laser-based
display system in which a laser receiver is mounted on the front
of the machine on top of an electric mast. It provides information
for the operator to make manual adjustments to the cutting edge,
thus speeding up grading operations. The second use involves laser-based
grade control, which adds proportional valve controls to the machine’s
hydraulics, allowing it to be an automatic system. The third level
of laser use is complete 3D grade control augmented by laser technology.
The decision to invest
in laser use, says Ward, is easier when one looks toward “scalable”
technologies, or those that are easy to upgrade. Scalable technology
is the concept of building systems (hardware, software, and firmware)
that allow users to add features and grow new capabilities in the
future without sacrificing the initial investment—one which
Ward says can be recouped rather quickly with continued expenses
for laser use being manageable. He adds that display systems, which
range from $1,000 to $5,000, can be moved from machine to machine,
making them a flexible and viable choice.
“For most, cost
is the driving force,” says Fred Rogers, machine automation
and sales director for Leica Geosystems. He says that the cost to
automate the elevation or lift of a dozer could range from $4,500
all the way up to $20,000. On the other hand, he stresses, for most
3D GPSs, costs could start at around $75,000 and run up to well
over $100,000. Rogers adds that most Leica Geosystems laser machine
automation systems can be upgraded to 3D.
Regardless of cost issues,
the big benefits of even the most entry-level laser products are
readily seen in areas such as labor cost savings, finished grading
accuracy, rough grading efficiency, overall production levels, and
safety.
Lasers and Small Machines
Bobcat Marketing Manager Lance Mathern says that using a laser-guided
system with compact equipment can eliminate the need for an onsite
survey crew to continuously check the grade. It also reduces labor
needs and costs, enabling workers to complete other projects and
improve overall production levels.
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PHOTO: CASE |
Mathern points to concrete
and asphalt flatwork as the most common application for compact
equipment combined with laser-guided attachments. “Tasks may
include curb and gutter work, new roads, driveways, commercial parking
lots, or specialty projects such as repairing or building tennis
courts. Also, the attachment and loader’s compact design enables
efficient work inside of structures, such as grading a new concrete
slab for an existing building,” says Mathern.
Bobcat manufactures two
attachments for use with a laser-guided system: the box blade and
the grader attachment, which are both approved for use with select
Bobcat skid-steer loaders, compact track loaders, and all-wheel
steer loaders, Mathern says. For finish grading accuracy, the laser-guided
Bobcat blade attachment has a grade accuracy of plus or minus 0.25
inches. The laser system moves the blade up or down to keep the
base material exactly on grade. Without the laser-guided system,
the operator can utilize the box blade attachment to fill in low
spots, and push or carry materials to prepare the surface for final
grade. The operator controls the box blade attachment with switches
mounted on the loader’s steering levers for fingertip control
of the blade raise-and-lower function, explains Mathern.
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PHOTO: CASE |
Wade Peska of Sioux Falls,
SD–based Peska Construction has multiple Bobcat loaders and
three laser-guided grader attachments. “The time and labor
you save far outweighs the cost. We know what it costs to have two
extra men standing around with a check rod,” he says. Peska
Construction initiated its laser use in 1995, a decision that’s
helped the company land projects for major retailers such as Home
Depot and Wal-Mart. “We need tight tolerances for indoor flatwork.
The typical Wal-Mart is 150,000 to 200,000 square feet. So if we
were to lose one-eighth to one-quarter inch of concrete material,
that’s a pretty big deal. By using a laser-guided system, the
tolerance tightens considerably, which saves big on the yield that
we get out of our product. It usually works out to be a 3% to 4%
waste factor for that one-eighth inch of material. So when we look
at that over the span of 1 million to 2 million square feet, the
cost of laser-guided equipment is virtually next to nothing,”
he says.
Another Bobcat customer
reports an overall increase in production levels. Colin and Basil
Rissolo of Stratford, CT, use their laser-guided grader attachment
and skid-steer loader to build and repair tennis courts. The Rissolos
say that with the laser system, they can grade a tennis court in
just two days—a job that took nearly eight days in past years,
when the company used a motor grader. Its 8-foot blade had to be
manually controlled to follow stakes and string lines to achieve
the desired base and finished grade. Due to the increased accuracy
of laser-guided grading, the company can produce a flatter, more
uniform surface for the courts.
Laser technology is also
used on tennis courts in southern California and bike paths in Minnesota,
says Topcon Regional Sales Manager Bill Painter, who points to the
use of small LeeBoy paving machines equipped with electrical and
hydraulic interfaces that integrate with Topcon’s laser systems.
Also on the sports-related
front is Denis Griffiths and Associates, a Georgia-based design-build
golf course architect that accesses Topcon machine control to laser-grade
critical areas. The system includes a System Five paver control
panel, an LS-B4B receiver, and an RLH-2SA laser transmitter, all
of which operate a proportional valve that controls a single-function
box blade. The result is a laser package that is ideal for a variety
of precision grading tasks.
Interior construction
is also a popular application. In Cedar Rapids, IA, two Mustang
skid-steer loaders are equipped with Topcon LSB-2 laser receivers.
A “smart” junction box is used to tie the transmitters
to a hydraulic valve that controls a flat blade. A Topcon RLH-2SA
laser transmitter is used to guide both machines simultaneously.
The Mustang skid-steers are used for sub-grade operations to obtain
the correct elevation and eliminate overruns in the stone base.
The stone is finish-graded with the Mustangs and Topcon’s system,
producing a surface that is ready for the concrete slab.
Roger Bryant Excavating,
a small operation located in Mason, OH, illustrates a residential
basement construction application, one that involves laying a gravel
base for preformed concrete walls. Bryant uses a Bullseye 5+ laser
receiver manufactured by Apache Technologies. Mounted on his Bobcat
skid-steer, the Bullseye product detects laser light generated by
any rotating laser transmitter and then gives him a visual indication
of which direction to move the blade or bucket to reach grade. Bryant
says the big advantage is that he can complete the entire job without
getting out of the cab once. “That’s a great timesaver.
One of my competitors still does things the old way. I’ll bet
he has to get out of his cab 50 or 60 times a day to make sure he’s
within grade,” he says.
Views From the Manufacturing
Front
Trimble is one of the leading providers of GPS technology.
Recently the company acquired Apache Technologies to extend its
laser product portfolio for handheld laser detectors and entry-level
machine displays and control systems. “Laser transmitters and
receivers have a range of features today that make them very easy
to set up and use as laser-guidance systems on compact equipment,”
says Pat Bohle, vice president of marketing and OEM sales for Trimble’s
Construction Division. Bohle says that the efficient use of laser
systems requires very little training. He stresses that anyone who
has used a laser level on the construction site can use a laser-based
display system on a compact machine. Bohle goes on to explain that
setup is easy and typically involves the following: (1) setting
up the grade laser or laser level on the job site to provide the
level or sloped plane reference; (2) transferring the elevation
reference to the machine; and (3) mounting the laser receiver on
the machine. “On a skid-steer, it’s often mounted on the
cab. On a backhoe or mini excavator, it’s usually mounted on
the boom,” says Bohle, who adds that typically a laser-based
display system does not use an onboard computer or an additional
controller. The laser receiver itself provides the visual reference
to the operator via bright LEDs and an audible beep, he says.
Bohle is quick to highlight
the Trimble CR600 Laser Receiver as a system that’s ideal when
utilized on backhoes, small excavators, and skid-steers. “It’s
used as both a handheld and a machine-mounted laser receiver—making
it a very flexible option for general contractors who do a range
of elevation work on the construction job site,” he says. “To
increase its versatility, the magnetic mount allows it to easily
attach to the cab or boom, or to be moved from machine to machine,”
he says.
Sales and Marketing Manager
Mike Bank of Apache Technologies says that the evolution of attachments
is the major impetus behind the growth of laser-guided products
on compact equipment. “As more and more attachments are developed,
more applications for laser systems arise. Additional features added
to visual indicate receivers have made them more accurate and easier
to use,” he says. Some of the newer features for excavation,
he says, include internal plumb sensors, as well as methods of compensation
for dipper angle. “For both visual and automatic grading, tilt
sensors help the contractor keep the blade level or at a preset
angle. For automatic systems, the use of fully proportional or linear
photocells combined with proportional valves allows the system to
react smoothly and precisely. Also, plug-and-play utilizing the
machine’s onboard hydraulics is another area where progress
is being made,” he says.
Bank notes that small
to midsize contractors generally make a step-by-step progression.
He explains that they start by using a laser system that consists
of a standard handheld detector and grade rod. Then they progress
to mounting lasers on machinery, first with a visual indicate system,
then eventually going automatic. “Our goal at Apache is to
re-index the entry-level point of visual indicate as well as automatic
machine control. Our systems are very flexible as they allow a contractor
to use the receiver one day on his automatically controlled push
box attachment, and use it the next day on his backhoe or excavator
as a visual indicate receiver. The ability to use laser-guided systems
every day makes them a necessary tool for even the smallest companies,”
says Bank.
Next, one of Topcon’s
latest offerings suitable for compact equipment is the LSB-3, a
visual indicate system that runs at a cost under $2,000. Topcon
Regional Sales Manager Bill Painter says the system attaches to
any piece of equipment with magnets. “There are no cables or
control boxes needed, and the unit runs on readily available C-cell
batteries. It gives the operator visual indication via signal lights
on his equipment’s cutting edge in relation to the planned
grade. The LSB-3 is designed to operate with Topcon’s RL-H3C
laser transmitter,” he says.
Another recent addition
to the laser lineup is the Economy Indicate System manufactured
by Leica Geosystems. The system allows the user to operate the sensor
and a display from the machine’s cab with a single battery
pack. The display has audio tones and visual LED indicators for
high, low, and on-grade. The company says that the system is very
universal and easy to move from machine to machine. “Laser
use increases productivity by 30% to 50%,” says Leica Machine
Automation and Sales Director Fred Rogers. “The cost and material
savings of laser guidance and control are undeniable. As technology
evolves and new ways of building are discovered, there is no doubt
that lasers will always play a part in the construction industry,”
he says.
Construction-industry
writer and frequent contributor Carol Wasson owns JCL Marketing
& Communications Inc.
GEC
- November/December 2005
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