Ryobi CCW180LBC - Bucking Under Stress; Cutting Types: Overbucking and Underbucking

17
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difcult
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 18 - 19.
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 underbucking. Then
makethenishingcutbyoverbuckingtomeetthe
rst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rstcutdeeperthan1/3ofthediameter
of the log.
Give special attention to logs under stress to prevent
the bar and chain from pinching.
When bucking on a slope, always stand on the uphill
sideofthelogasshowningure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 19.
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 to push back
at you. Be prepared for this reaction and hold the
sawrmly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
balance or control of the saw.
LOAD
FINISHING CUT
1ST CUT
1/3 DIA
LOG SUPPORTED AT ONE END:
LOG SUPPORTED AT BOTH ENDS:
FINISHING CUT
1ST CUT 1/3 DIA
LOAD
Fig. 18
Fig. 19
OVERBUCKING
UNDERBUCKING
OPERATION