Sears 358.356090-3.7/20" - Manual (Page 14)

TYPES OF CUTTING
BASIC CUTTING TECHNIQUE
1. IMPORTANT POINTS.
a. Cut wood only. Do not cut metal, plastics,
masonry, non-wood, building materials: etc.
b. Stop the saw if the chain strikes a foreign
object. Inspect the unit and repair or replace
parts as necessary.
c. Keep the chain out of dirt and sand. Even a
small amount of dirt will quickly dull a chain and
thus, increase the possibility of kickback.
2. UNDERSTAND REACTIVE FORCES
Pushback and Pull-in occur when the chain is
suddenly stopped by being pinched, caught,
...... or by contacting a foreign object in the wood.
i This results in a reversal of the chain force used
' to cut wood and causes the saw to move in the op­
; posite direction of chain rotation, resulting in loss
; of control and possible serious personal injury.
• Pushback:
—occurs when the chain, on top of the bar, is sud­
denly stopped when the top of the bar is used for
cutting.
—drives the saw straight back toward the operator,
possibly causing loss of saw control.
To avoid Pushback:
a. Be extremely aware of situations or
obstructions that may cause material to stop
or pinch the top of the chain.
..b. Do not cut more than one log at a time.
c. Do not twist the saw as the bar is withdrawn
...... from an under-cut. ....................
• Pull-in:
■—occurs when the chain on the bottom of the bar
is suddenly stopped.
; — occurs when the spike or saw housing is not held
securely againstthetree or limb and/or when the
cut is not begun at full throttle.
; —pulls the saw forward, arid could cause the
operator to lose control.
To avoid Pull-in:
a. Always begin cutting with the engine at full
throttle and the spike against the wood.
b: Use wedges made of plastic, wood, or light
alloy (never of steel or iron) to hold the cut
open.
3. PROCEDURE
Practice cutting a few small logs using the follow­
ing technique to get the “feel” of using your saw
before you begin a major sawing operation.
a.
Accelerate the engine to full throttle Just be­
fore entering the cut by squeezing the Throt-
tie Trigger.
...... b,.. Begin cutting with the spur against the log..........
Figure 26.
c. Keep the engine at full throttle the entire
time you are cutting.
d. Allow the chain to cut for you ; exert only light
downward pressure. If you force the cut, dam­
age to the bar, chain or engine can result.
e. Release the throttle trigger as soon as the
cut is completed, allowing the engine to idle,
if you run the saw at full throttle without a cut­
ting load, unnecessary wear can occur to the
chain, bar, and engine.
f. Do not put pressure bn the saw at the end
of the cut to avoid losing control when the cut
is complete.
g. Stop the engine before setting the saw
down after cutting.
BEGIN CUTTING WITH THE
SPUR AGAINST LOG.
Figure 26
B. TREE FELLING TECHNIQUES..................
1. PLAN YOUR SAWING OPERATION CARE­
FULLY IN ADVANCE
a. Clear the work area. You need a clear area all
around the tree where you can have secure
footing.
b. Study the natural conditions that can cause
the tree to fall in a particular direction:
1. ) The WIND direction and speed
2. ) The LEAN of the tree
3. ) WEIGHTED with BRANCHES on one side
4. ) Surrounding TREES and OBSTACLES
c. Look for decay and rot. If the trunk is rotted,
it could snap and fall toward the operator.
d. Check for broken or dead branches which
couid fall on you while cutting.
e. Make sure there is enough room for the tree
to fall. Maintaining a distance of 2 V 2 tree
lengths from the nearest person or other ob­
jects. Engine noise may drown out warning
call.
f. Remove dirt, stones, loose bark, nails,
staples, and wire from the tree where cuts
aretobemade.
g. Plan to stand on the up-hill side when cut-
tingonaslope.
h. Plan a clear retreat path to the rear and
diagonal to the line of fall. Figure 27.
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