Ryobi RY40502 Manuel D'utilisation page 20

tree and make sure there are no obstructions
in your planned path of retreat. Clear path of
safe retreat approximately 135° from planned
line of fall. The retreat path should extend back
and diagonally to the rear of the expected line
of fall. See Figure 13.
 Before felling is started, consider the force and
direction of the wind, the lean and balance of
the tree, and the location of large limbs. These
things influence the direction in which the tree
will fall. Do not try to fell a tree along a line
different from its natural line of fall.
 The chain saw operator should keep on the
uphill side of the terrain as the tree is likely to
roll or slide downhill after it is felled.
 Remove dirt, stones, loose bark, nails, staples,
and wire from the tree where felling cuts are to
be made.
 Notched Undercut. Cut a notch about 1/3
the diameter of the tree, perpendicular to the
direction of fall. Make the cuts of the notch so
they intersect at a right angle to the line of fall.
This notch should be cleaned out to leave a
straight line. To keep the weight of the wood
off the saw, always make the lower cut of the
notch before the upper cut. See Figure 14.
 Felling Backcut. The backcut is always made
level and horizontal, and at a minimum of 2
in. above the horizontal cut of the notch. See
Figures 14 - 15.
 Never cut through to the notch. Always leave a
band of wood between the notch and backcut
(approximately 2 in. or 1/10 the diameter of the
tree). This is called "hinge" or "hingewood." It
controls the fall of the tree and prevents slipping
or twisting or shoot-back of the tree off the
stump. See Figures 14 - 15.
 On large diameter trees, stop the back cut
before it is deep enough for the tree to either
fall or settle back on the stump. Then insert
soft wooden or plastic wedges into the cut so
they do not touch the chain. The wedges can
be driven in, little by little, to help jack the tree
over. See Figure 16.
 As tree starts to fall, stop the chain saw and put
it down immediately. Retreat along the cleared
path, but watch the action in case something
falls your way. Be alert for overhead limbs or
branches that may fall and watch your footing.
OPERATION
WARNING:
Never cut through to the notch when making a
backcut. The hinge controls the fall of the tree,
this is the section of wood between the notch
and backcut.
BUCKING
See Figures 17 - 20.
Bucking is the term used for cutting a fallen tree
to the desired log length.
 Always make sure your footing is secure and
your weight is distributed evenly on both feet.
 Cut only one log at a time.
 Support small logs on a saw horse or another
log while bucking.
 Keep a clear cutting area. Make sure that no
objects can contact the guide bar nose and
chain during cutting, this can cause kickback.
 When bucking on a slope, always stand on
the uphill side of the log. To maintain complete
control of the chain saw when cutting through
the log, release the cutting pressure near the
end of the cut without relaxing your grip on the
chain saw handles. Do not let the chain contact
the ground. After completing the cut, wait for the
saw chain to stop before you move the chain
20 - English
LOG SUPPORTED AT ONE END:
FINISHING CUT
LOG SUPPORTED AT BOTH ENDS:
LOAD
1ST CUT 1/3 DIA
FINISHING CUT
LOAD
1ST CUT
1/3 DIA
Fig. 19