To Avoid Kickback; Saw Chain Cutter Sharpness - Makita EA7300P Operator's And Safety Manual

Many factors influence the occurence and force of
the kickback reaction. The type of bar and saw chain you
use is a factor in the force of the kickback reaction.
The speed of contact at which the cutter contacts
the object.
Kickback force increase with the rate of impact.
The contact angle between the nose of the bar
and the foreign object (fig. 11).
Kickback is most pronounced in the upper quadrant
of the bar nose.
MAKITA chain types are designed to reduce kickback
forces.
The depth gauges:
Improper lowering of the depth gauges also increases
the risk of a kickback.

Saw chain cutter sharpness:

WARNING!
A dull improperly sharpened chain may increase the
risk of kickback. Always cut with a properly sharpened
chain.
Devices for reducing the risk of kickback injury
MAKITA have developed a special chain brake to reduce
the risk of kickbacks.
This chain brake increases the safety factor on the
job, e.g. when the saw suddenly bucks upwards the chain
stops rotating within a fraction of a second.
A deflection guard on the disengaging lever of the chain
brake and a scoop rear handle ensure that the operator's
hands are fully protected at all times.
Kickback tendency increases as the radius or size of
the guide bar nose increases. MAKITA have developed
guide bars with small nose radius, to reduce the kickback
tendency.
WARNING!
No chain brake prevents kickback.
These brakes are designed only to stop the chain,
if activated.
To ensure a proper operation of the chain brake, it
must be properly maintained.
Furthermore, there must be a sufficient distance
between the operator and the bar to ensure that the
chain brake has sufficient time to activate and stop
the chain before potential contact with the operator.
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To avoid kickback

The best protection from personal-injury that may
result from kickback is to avoid kickback situations:
1. Hold the chain saw firmly with both hands and
maintain a secure grip.
2. Be aware of the location of the guide bar nose at all
times.
3. Never bring the nose of the guide bar in contact with
any object.
Do not cut limbs with the nose of the guide bar. Be
especially careful with small, tough limbs, small
size brush and saplings which may easily catch the
chain.
4. Don't overreach.
5. Don't cut above shoulder height.
6. Begin cutting and continue at full throttle.
7. Cut only one log at a time.
8. Use extreme caution when reentering a previous
cut.
9. Do not attempt plunge cuts (see page 5) if you are
not experienced with these cutting techniques.
10. Be alert for shifting of the log or other forces that may
cause the cut to close and pinch the chain.
11. Maintain saw chain properly. Cut with a correctly
sharpened, properly tensioned chain at all times.
12. Stand to the side of the cutting path of the chain
saw.
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