Ryobi RY43154 Operator's Manual page 23

 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 18.
 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 18 - 19.
 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 18 - 19.
 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 20.
 When bucking or felling with a wedge, it may
be necessary to remove the SAFE-T-TIP anti-
kickback device to allow the bar to be drawn
through the cut. After you complete the cut,
reinstall the tip 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.
WARNING:
Never cut through to the notch when making a
back cut. The hinge controls the fall of the tree,
this is the section of wood between the notch
and backcut.
OPERATION
BACK CUT
2 in.
BACK CUT
WEDGE
Page 23 — English
HINGE
2 in. OR 1/10 DIAMETER
NOTCH -
APPROX. 1/3
DIAMETER OF
TRUNK
Fig. 18
HINGE
Fig. 19
Fig. 20