Ryobi P2108 Manuel D'utilisation page 90

will fall. Do not try to fell a tree along a line dif-
ferent 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 direc-
tion 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 Fig-
ures 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 slip-
ping 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.
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.
OPERATION
BACK CUT
BACK CUT
HINGE
22 - English
HINGE
2 in. OR 1/10 DIA
2 in.
WEDGE
NOTCH -
APPROX. 1/3
DIAMETER OF
TRUNK
Fig. 14
NOTCH
Fig. 15
Fig. 16