Other X500 features include:
- A Variable Cutting System (VCS) on its four-track models so contractors can change out the drum to make 2-, 3-, or 4-ft. cuts. Roadtec also rents the VCS system.
- Forward and reverse milling so contractors can pulverize pavement
- Grade and slope controls, which are increasingly important as milling for smoothness and profile is in demand
- Two conveyors: A primary conveyor that takes the material out of the drum to the secondary conveyor; a secondary conveyor, which offers a 60-degree swing on either side, loads the material into the truck.
Irvine says that 80% of the 500 class units Roadtec sells are four-track machines, but interestingly about 90% of the largest milling machines the company sells are three-track models.
"The three-track is very popular on the large machine," Irvine says. "A lot of asphalt paving contractors who own the 500 and who aren't as familiar with milling are sold on the fact that you have to have four tracks to have more stability."
Irvine says many contractors just getting involved in milling prefer the four-track machine because they've been conditioned to think the four tracks are more stable than three.
"They don't want it to tip, and they think the four tracks will prevent that," he says. "But often a four-track machine will tip because one of the tracks is up in the air and the operator doesn't realize it. You can't do that with a three-track machine because all three tracks are always on the ground."
But he adds that contractors who use the mill on parking lots are often working on thinner asphalt pavements. "In those cases the fourth track, which provides greater flotation, is an advantage so the contractor doesn't crack the pavement.
"It's our best seller because it's a well-rounded piece of equipment," Irvine says, adding that the high horsepower enables a contractor to use it on larger jobs such as county roads and suburban streets, as well as smaller jobs such as trench milling and parking lots.
Plus, the reduced weight enables the contractor to move it more easily and without extensive permitting required by heavier pieces of equipment.
"Large contractors employ people to handle the permitting for them, but the smaller guys have to do it all themselves so any equipment that doesn't require extensive permitting is a real help to a contractor, especially to the smaller guys," Irvine says.
And Irvine says that's especially important with the X500 which, because of its weight, high horsepower, and versatility, can be used on several jobs in a day.
"So it's easy to move from job to job, and with the high horsepower you can do a variety of different jobs where the job or depth of the asphalt is big or small," he says. "It's a nice light machine that you can get a blanket permit to go wherever they want to go."
Utility mill: Volvo's MW500
Launched in the spring of this year, Volvo's MW500 utility mill has been well received by contractors, according to Patrick Wakefield, Volvo Construction Equipment's road segment manager for milling. The MW500 is a rubber-tired machine with four tires as opposed to a track unit. Its 20,062-lb. operating weight includes the optional conveyor which adjusts up, down, and up to 25 degrees to each side and features a quick disconnect. A 20-in. drum mounted in the rear of the unit mills to 8.3 in. deep, and a 158.5-gal. water tank feeds the spray bar in the drum housing, cooling, and cleaning the teeth and reducing dust.
"What the contractor is looking for in this class is maneuverability and versatility," Wakefield says. "Contractors use the MW500 a lot for patching, work on city streets, in alleys, and cutting joints in larger roadways; a lot of jobs where you need maneuverability. You can get a good tight radius with this machine."
Wakefield says the MW500's turning radius of just under 8 in. enables the mill to cut around manhole covers and other obstacles, so it's often used behind half-lane milling machines to reduce the amount of handwork, such as jack hammering, that might otherwise be required. When flush cutting is required the unit's right rear support leg and wheel can be swiveled inboard, allowing the MW500 to get closer to curbs and walls.