Ryobi RY40500 Manuel D'utilisation page 19

 When bucking on a slope, always stand on the
uphill side of the log. To maintain complete con-
trol 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
saw. Always stop the motor before moving from
tree to tree.
 Sometimes it is impossible to avoid pinching
(with just standard cutting techniques) or difficult
to predict which way a log will settle when cut.
To avoid pinching while cutting, rotate or move
the log so that the pinch is eliminated.
BUCKING LOGS UNDER STRESS
See Figures 20 - 21.
When the log is supported along its entire length,
it should be cut from the top or overbucking.
When the log is supported on one end, cut 1/3
the diameter from the underside or underbuck-
ing. Then make the finishing cut by overbucking
to meet the first cut.
As the log is being cut, it will tend to bend. The saw
can become pinched or hung in the log if you make
the first cut deeper than 1/3 of the diameter of the log.
Give special attention to logs under stress to pre-
vent the bar and chain from pinching.
When bucking on a slope, always stand on the uphill
side of the log as shown in figure 18. When "cutting
through," to maintain complete control of the chain
saw, 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 saw. Always
stop the motor before moving from tree to tree.
TYPES OF CUTTING USED
See Figure 21.
OVERBUCKING
Begin on the top side of the log with the bottom
of the saw against the log; exert light pressure
downward. Note that the saw will tend to pull
away from you.
UNDERBUCKING
Begin on the under side of the log with the top
of the saw against the log; exert light pressure
upward. During underbucking, the saw will tend
OPERATION
1
CUT LIMBS ONE AT A TIME AND LEAVE SUPPORT LIMBS
fIRST CUT
1/3 DIAMETER
fINISHING CUT
to push back at you. Be prepared for this reaction
and hold the saw firmly to maintain control.
WARNING:
Never climb into a tree to limb or prune. Do not
stand on ladders, platforms, a log, or in any
position which can cause you to lose your bal-
ance or control of the saw.
LIMBING
See Figure 22.
Limbing is removing branches from a fallen tree.
 Work slowly, keeping both hands on the chain
saw with a firm grip. Always make sure your
footing is secure and your weight is distributed
evenly on both feet.
 Leave the larger support limbs under the tree to
keep the tree off the ground while cutting.
 Limbs should be cut one at a time. Remove the
cut limbs from the work area often to help keep
the work area clean and safe.
 Branches under tension should be cut from the
bottom up to avoid binding the chain saw.
19 - English
2
UNDER TREE UNTIL LOG IS CUT
SECOND CUT
LOAD
3
4
Fig. 22
Fig. 23