Use and Care Manual

SRM-225I OPERATION

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Reaction Forces

Push or Pull - Kickback or 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

dibrection of the force depends on the side of the blade

eing 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.

Kickout

Kickout is also a reactive force caused by resistance to

cutting, but the direction of blade thrust is lateral (to the left or right of the

blade), instead of forward or back toward the operator. In most cases, Push,

Pull, and Kickout can be reduced or eliminated by: