Cutting Techniques - sunjoe SWJ700E Manual Del Operador

7. Allow the chain to cut for you; exert only light downward
pressure. If you force the cut, damage to the bar, chain, or
unit can result.
8. Do not put the pressure on the saw at the end of the cut.
9. Always cut with both feet on solid ground to prevent being
pulled off balance.
10. Do not cut above chest height, as a saw held higher is
difficult to control against kickback force.

Cutting Techniques

Before felling or delimbing for the first time, practice sawing
logs on the ground or on trestles, so that you can get familiar
with the machine and the most suitable sawing techniques.
When felling a tree, keep everyone a safe distance from the
cutting area. During felling operation, the safest distance
should be at lease twice the height of the largest trees in the
felling area. If the tree makes any contact with utility line, the
utility company should be notified immediately.
m
WARNING!
Always hold the machine with both hands
when sawing.
m
WARNING!
Stop the motor immediately if the chain
stops during sawing. Beware of kickback, which can occur if
the bar contacts an obstacle.
• Felling a tree
i) When bucking and felling are performed by two or more
people at the same time, the felling operation should be
separated from the bucking operation by a distance of at
least twice the height of the tree being felled. Trees should
not be felled in a manner that would endanger any person,
strike any utility line or cause any property damage.
m
WARNING!
Check the tree for damaged or dead
branches that could hit you during the felling.
ii) The chain saw operator should stay on the uphill side of
the terrain, as the tree is likely to roll or slide downhill after
it is felled.
iii) An escape path should be planned and cleared as
necessary before cuts are started. The escape path should
extend back and diagonally to the rear of the expected line
of fall as illustrated (Fig. 16).
Fig. 16
iv) Before felling is started, consider the natural lean of the
tree, the location of larger branches and the wind direction
to help you judge which way the tree will fall.
m
WARNING!
Do not fell trees in the period of high wind
or heave precipitation. Wait to do your cutting until the hazard
has ended.
m
WARNING!
Do not cut down trees that have an
extreme lean or large trees that have rotten limbs, loose bark,
or hollow trunks. Have these trees pushed or dragged down
with heavy equipment, and then cut up.
v) Remove dirt, stones, loose bark, nails, staples, and wire
from the tree.
• Notching undercut
Make the notch 1/3 the diameter of the tree, perpendicular to
the direction of the fall as illustrated (Fig. 17).
Fig. 17
Make the lower horizontal notching cut first.
This will help to avoid pinching either the saw chain or the
guide bar when the second notch is made.
• Felling back cut
i) Make the felling back cut at least 2 in. (50 mm) higher than
the horizontal notching cut as illustrated (Fig. 17). Keep
the felling back cut parallel to the horizontal notching cut.
Strategically position the felling back cut so that enough
wood is left to act as a hinge. The hinge wood keeps the
tree from twisting and falling in the wrong direction. Do not
cut through the hinge.
ii) As the felling gets close to the hinge, the tree should begin
to fall. If there is any chance that the tree may not fall in
the desired direction or it may rock back and bind the saw
chain, stop cutting before the felling back cut is complete
and use wedges of wood, plastic, or aluminium to open
the cut and drop the tree along the desired line of fall.
iii) When the tree begins to fall, remove the chain saw from
the cut, stop the motor, put the chain saw down, then use
the retreat path planned. Be alert for overhead limbs falling
and watch your footing.
14