Most box blade attachments, such as the one mounted to this Bobcat T180, are equipped with laser grade control systems because they are less expensive than a 3D solution and provide a rapid return on investment.
Grade control systems are migrating to smaller machines as end users discover the economic advantages. Tight spaces, landscaping and smaller jobs often favor the use of smaller equipment and attachments vs. larger dedicated units. Consequently, suppliers of grade control technology are offering a range of solutions that vary in sophistication, capability and price.
For instance, Trimble offers a portfolio of solutions suited for box blades and other finishing/landscaping attachments. "The solutions offered range from simple indicator light systems, plumb and tilt indication, to fully automatic blade control," says Tim Baker, segment manager - site preparation.
Likewise, Leica Geosystems claims it has an installed literally hundreds of systems on box blades. These are mainly laser-based systems. "Laser-based systems are extremely simple and easy to use," says Rich Calvird, program manager for machine control. "All the operator has to do is put the system in 'automatic' mode. Laser beacon references are easy to set up and are common on today's construction and landscaping sites, so users are ready to go in minutes."
These 2D systems are well proven. "With full automatic systems available for less than $10,000, the savings in fuel, machine time and material handling usually pay for the system within a few months, and keep on generating savings for increased profit for years afterward," says Calvird.
The advent of 3D solutions promises even more capability, but at a higher price. "The 3D systems offer greater flexibility to handle complex land contours, larger sites and multiple machines working in the same general area," says Calvird. "If the job does not have the complexity or size demands needing full 3D capability, a laser system will be more cost effective."
But 3D grade control technology is starting to become more prevalent in attachment applications. "We have so many smaller contractors who are investing in the technology because it is not only user friendly, it makes sense for them to know where they are all of the time," says Bob Highfill, 3D machine control, Topcon. For example, consider its application on a box blade. "You can send a good operator out on the job and not even have another guy with him. He knows exactly where everything is and where it needs to be."
Shane Thomas Construction, Forest Hills, CA, is a small operation that has discovered the benefits of running a dual antenna Topcon GPS system in indicate mode on its Case 570 MXT skip loader with a box blade. The skip loader has a lot of advantages over a dozer or motor grader. "It is a lot cheaper," says Shane Thomas. "A new skip loader is $60,000. And because you are on tires instead of undercarriage, the operating costs are low."
However, you need to work within its capabilities. "The skip loader is not for moving bulk dirt," says Thomas. You need to be within a foot of grade. Yet, its ability to work in tight areas with a box blade attachment is a real benefit.
"I am kind of a specialist with this tractor. I will do the ridges, the valleys and all of the stuff that would take a blade time. I take away all of the technical stuff, and [the motor grader operator] just goes for square footage," says Thomas. "On a commercial parking lot, you will have a lot of flow lines. You will have a lot of valley gutters." This is where the Topcon system has proven useful. "It shows you the cutoff points for the different sections."
Thomas recalls a recent project that was over 2 million sq. ft. There was just a motor grader and a skip loader with box blade on the site. "We were averaging about 250,000 sq. ft. a [week]," he notes. "I could do 50,000 up to 75,000 sq. ft. a day. I roughed it in so fast."
The productivity with the Topcon system has been a real benefit, along with the modifications Thomas has made to the box blade. "I took the Gannon box off of it and it has a kind of screed on it like a paving machine," he explains. "When I go to do rock, it contains all of the material. I don't have windrows. I make one pass and I am done."
The results are impressive. "I have done almost 90,000 sq. ft. a day finish grading with a tractor," says Thomas. "A good blade man is supposed to do about 70,000 sq. ft."
Not having to wait for a grade checker accounts for much of the productivity gain. "If you have a super-aggressive grade setter, it would be about a wash, but those are real hard to find," says Thomas. "Then you have the overhead of a grade setter. You are paying overtime." That isn't including the cost of lathe and materials.
Roughing it in the old way also means working around stakes. "You have no stakes in the way anymore," says Thomas. This speeds up the grading process.
In addition to subcontracting for larger contractors, Shane Thomas Construction also tackles its own projects. "When I do my own jobs, I have a guy who makes all of my maps," says Thomas. "I don't have time to do that." He admits that the technology is as good as the person creating the maps. "But as far as the system, it has never let me down."
With the skip loader and GPS system, Shane Thomas Construction is well equipped to handle smaller jobs. "On most of the small parking lots we do that are under 100,000 sq. ft., I will not even bring a blade in for it," says Thomas. A dozer may be used to rough it in, but then the box scraper is used for the finish work.
The accuracy of the box blade with the GPS system has proven more than adequate for Shane Thomas Construction. It is within half of a tenth of a foot. "That is within any tolerance that I have seen," says Thomas. It also saves valuable time during finish grading since you're not moving the material twice. "Your finish time is cut in half."
The price of entry for 3D systems can be intimidating. "The initial investment is pretty high," Thomas admits.
But you have to take into account the grade setter you may be currently employing. If this person isn't bogged down with staking, he or she can be utilized elsewhere. "You can free up a grade setter to do other tasks," says Thomas. "I have one there, usually running other equipment. You eliminate the staking."
It's also not necessary to immediately run out and purchase a system. "You can rent the systems, too. That's what I did," recalls Thomas. "I rented it a bunch of times, and [Topcon] gave me a good deal on the one that I am running."
If you don't need to grade complex 3D profiles, 2D laser-based systems promise a rapid return. "When grade control systems for box blades and other landscaping tools are implemented, it eliminates the 'guessing' factor in terms of where finished grade is. [This increases] the efficiency and productivity of the skilled and unskilled operator, machine and process," says Baker.
"As these systems put the grade information on the machine with the operator, the time and cost of a grade checker is greatly reduced," he adds. "With the time, material and man-hour savings, it is conceivable to cover the costs of a new system on the first job."
Swapping between equipment
Unlike a production-based finishing tool such as a motor grader, the ability to move grade control systems around is important with attachments to maximize utilization. "For towed implements, quick and easy attachment to the tractor is a major consideration for cabling and hydraulic fittings," says Calvird. "Compact panel and sensor designs are needed to make moving from machine to machine simple."
According to Highfill, the Topcon GPS system can be easily swapped between different grading tools, so it is always on the proper tool for the given application. And once the system has been purchased for your production machines, it doesn't require much additional investment to be adapted to attachments.
"You have the versatility of swapping the control box, antenna and receiver. It is very simple," he says. "You can take a system off a dozer or a motor grader and put it on the box blade."
For example, you might use a GPS grade control system on a dozer for bulk earthmoving, then move it to a motor grader for finish work. "Then you swap that onto the box blade to be able to do the corners of a parking lot or for sub grade," says Highfill. "After the job is done, you can do landscaping in between the curbs or in the median of a freeway."
Shane Thomas Construction takes advantage of the portability of these systems. "I have taken it off [the box blade] and put it on my backhoe," says Thomas. "I put it on my dozer to rough in."
This eliminates any wasted time spent checking progress while rough grading. "You think you have it good, then you have to get off [the machine] and check it, especially if you are a small guy like me," says Thomas. "With the Topcon system, I just put it on there, dial in the section and I am done."
Ease of setup
Thomas says setup of the GPS grade control system is easy. Once it is hooked up, you simply need to calibrate it. "Basically, all you do is turn on the system," he says. "Then you have your grade setter set a benchmark."
For instance, Shane Thomas Construction often uses a manhole as a reference point. The elevation is painted on the manhole, then the box blade is lowered onto this known point and calibrated. "It takes about three minutes," says Thomas. "You dial it in, then just push a button."
A 2D laser-based systems offers even simpler setup and operation. Laser machine controls are typically used for these applications. "Although there are 3D systems that could be used for these applications and machines, the laser-based systems provide contractors with an economical and easy to set up and use solution for smaller machines," says Baker. "Rotating laser transmitters using hand-held receivers have been on construction jobsites since the '70s, so any possible drawbacks are understood and controlled."
The complexity of the 2D system hardware really depends on the chosen system. "Operator-controlled or 'display' systems use a machine-mounted laser receiver with red lights directing the user from above and below, and green on-grade lights directing the user as to which direction to move the blade or bucket to grade," says Baker. "These display systems are easily moved from machine to machine for a variety of applications. This is especially important for compact machines, which are used for both finish grading and general utility."
Automatic grade control systems take a little more initial setup. "Automatic blade control systems are currently more integrated than display systems and are a more challenging installation," says Baker. "The advent and implementation of EH (Electro-Hydraulics) is potentially enabling quicker and simpler installations."
Whether you chose a 3D or 2D solution, indicate lights or full automation, grade control can turn your attachment into a smarter tool. "Some of the key benefits," says Baker, "include consistently controlling materials at each level of elevation; managing costs better; reducing passes to grade and reducing/eliminating rework; and improving cost and time savings, which directly impact the bottom line."