SRM-3020T OPERATION
Operating Techniques - Metal or Plastic Blade
Brushcutter blades may be used to cut and trim a wide variety of materials.
Refer to the blade selection section for determining the correct blade for the application.
Scything (3, 8, and 80 tooth weed/grass, and brush blades)
• To cut large sections of field grass and weeds swing the cutting head in a level arc, gradually feeding the blade into the material being cut. Adjust throttle speed according to your work.
• Do not swing the main pipe with arms. Turn hips to swing the blade horizontally from right to left, and cut weeds on the left side of the blade.
• Do not scythe back and forth as the grass may scatter and kickback may occur easily.
• Tilt blade left by 5 to 10 degrees so that cut grasses will push left, making progress easier.
• Move forward with each arc to cut a swath.
• Width of cutting swath depends on arc. Use a larger arc for a wider swath, or a smaller arc for a narrow swath.
Suggested cutting width is about 1.5 m (4.9 ft).
• When scything large brush up to 12.7 mm (0.5 in.) diameter from right to left, avoid cutting with highlighted section.
Reaction Forces
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The cutting attachment will continue to rotate even after the throttle is released, maintain control of the unit until it has come to a complete stop.
Blade thrust may occur when the spinning blade contacts an object that it does not immediately cut. Following proper cutting techniques will prevent blade thrust.
Blade thrust can be violent enough to cause the unit and/or operator to be propelled in any direction, and possibly lose control of the unit.
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OPERATION SRM-3020T
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Blade thrust can occur without warning if the blade snags, stalls or binds.
Blade thrust is more likely to occur in areas where it is difficult to see the material being cut.
Push or Pull - Kickout
During normal use, operating a brushcutter with a circular metal blade can produce sudden strong reaction forces that are difficult to control. Strong reaction forces can cause a loss of balance or loss of control of the equipment, resulting in serious injury to operator and bystanders.
Understanding what causes these reactive forces may help you to avoid them, and can help you to maintain control of the equipment if you experience a sudden reaction during cutting. Reactive forces occur when the force being applied by the cutting teeth of a blade meet resistance, and some of the cutting force is directed back toward the equipment. The greater the cutting force or the amount of resistance, the greater the reactive force.
Push and Pull Forces
Push and pull forces are reactive forces that push the equipment directly toward the operator, or that pull the equipment directly away from the operator. These forces are the result of cutting on the sides of the blade. The direction of the force depends on the side of the blade being used, and the direction of blade rotation at the point of contact. The reactive force is in the opposite direction of blade rotation at the contact point, regardless of where the contact is being made. These types of reactive forces are also called “Blade
Thrust.”
As shown in the illustration, a blade turning counterclockwise will cause the equipment to pull away from the operator if the point of cutting resistance is on the left side of the blade. If the point of cutting resistance is on the right side of the blade, the equipment will push back toward the operator. In both examples, the reactive force is in the opposite direction of blade rotation at the contact point where resistance occurs.
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