as on July, 2012 - til india

The Unsung HeroCat ® Motor Grader - Part IIMotor Graders are very versatile and mostly used in building roads from start tofinish, from close tolerance to finish grading. A high percentage of Motor Gradersare used in road maintenance, repair and rebuilding work on provincial and townshiproads. In our previous issue we discussed about the relevant terms and modes ofoperation that are commonly used while operating a Motor Grader. In this article,we will share the best practices for maintenance, clearing, building city townshiptype roads. This includes smoothing, shaping the travel surface, and providingdrainage to prevent road deterioration in inclement weather.6Road Maintenance TipsThe best time to dress a road is when moisture is present:after a rain or after the road h<strong>as</strong> been sprayed by a waterwagon. Maintain straight cutting edges by trimming themwith a torch or, if wear is not severe, by dragging thecutting edges on a smooth concrete surface. Replace edgesbefore wear occurs on the bottom of the moldboard andreduces cutting edge support. Drag the surface when hardand dry, with the cutting edge near 90 degrees to thesurface. Cut to the depth of major potholes and don't fillthese holes with loose dry material, because traffic willquickly displace the loose material and the holes will reappear.Maintenance work is normally done with the centershiftlock pin in the center position, and the drawbar and circlecentered under the mainframe. For maximum machinestability, the mainframe should be straight or articulatedslightly. Articulating the rear frame toward the toe of themoldboard approximately 2 to 5 degrees (1 to 1.5 timesthe width of the tire) will frequently help reduce themachine's tendency to bounce. Start with the moldboardtop 2 inches (5.1 centimeters) ahead of the cutting edge.Then adjust to the material and conditions. Use of full reartip could cause material penetration problems and damagethe moldboard bottom or pivot area, especially if the cuttingedges are worn.Use only enough down pressure to accomplish the t<strong>as</strong>k.Excessive down pressure on a hard dry surface causesrapid cutting edge wear, requires more horsepower andfuel and reduces productivity. Sliding and tire spinningincre<strong>as</strong>e front and rear tire wear. In extreme c<strong>as</strong>es,excessive down pressure may cause the cutting edges tosplinter causing tire damage.In road maintenance, cutting edges will wear quicker inthe center than at the ends. Three section edges aresometimes used: carbide edges in the center, hardenededges at the ends. Check edge wear frequently to preventmoldboard damage..To Extend Cutting Edge Life in RoadMaintenance, Maintain a Constant TipPositionSide View of moldboard cutting edge1. FootprintThe cutting edge tip angle can affect cutting edge lifewhen maintaining roads. The tip angle should position thecutting edge at 90 degrees to the road surface. In thisposition, down pressure on the moldboard places less stresson the cutting edge and retaining bolts. The edges willhave a tendency to ride over objects possibly preventingmachine damage.The fixed tip angle presents a constant edge thickness tothe wear surface for longer life. If you change the tip angleoften in this application, the sharpened edge will wearquickly, shortening its life.