Ryobi RY40800 Operator's Manual page 61

 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 15.
 Felling Backcut. The backcut is always made lev-
el and horizontal, and at a minimum of 2 in. above
the horizontal cut of the notch. See Figures 15 - 16.
 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 15 - 16.
 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 17.
NOTE: When bucking or felling with a wedge, it
may be necessary to remove the SAFE-T-TIP
anti-kickback nose guard to allow the bar to be
drawn through the cut. After the cut is complete,
the tip should be reinstalled immediately.
 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.
BUCKING
See Figures 18 - 21.
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.
OPERATION
®
UNDERBUCKING
21 - English
LOG SUPPORTED AT ONE END:
FINISHING CUT
LOG SUPPORTED AT BOTH ENDS:
LOAD
FINISHING CUT
OVERBUCKING
Fig. 19
LOAD
1ST CUT
1/3 DIA
1ST CUT 1/3 DIA
Fig. 20
Fig. 21