Sears 358.356090-3.7/20" Chainsaw User Manual


 
TYPES OF CUTTING .....
Ae 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,
m
Toavoid 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.
PROCEDURE
Practice cutting a few smalt logs using the follow-
ing technique to get the '_eel" 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-
tleTrigger.
...........................................o.r..by.#ontactinga, fore!gn.obje_ in_the_wood__...........................),....Begin cutting with the spur against the log.
This results in a reversal of the chain force used Figure 26,
to cut wood and causes the saw to move inthe op-
posite direction of chain rotation, resulting in loss
of control and possible serious personal injury.:'.
'e Pushback:
--occurs when the chain on top of the bar, is sud-
deftly stopped When the top of the bar is used for
cutting.
.... drives the saw straigl_t back toward the operator,
poss!bly causingloss of saw control.
To avoid Pushback:
a. Be extremely aware of situations or
obstructions that may cause material to stop
or pinchthe top ofthe chain.
....b. Do not cut more than one log at atime.
c. Do not twist the saw as the bar is withdrawn
=" from an under-cut_
c. Keep the engine at full throttle the entire
time you are cutting.
d. Allow the chain to Cutforyou; exert onlylight
downward pressure. If you force the cut, dam-
age tothe bar, chain oreng_ne 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 oh the saw at the end
of the cut to avoid Iosing controlwhen the cut
iscomplete.
g. Stop the engine before setting the saw
down after cutting.
e Pull-in:
R occurs when the chain on the bottom of the bar
is suddenly stopped.
-- occurs when thespike orsaw housing is not held
securely against the tree or limband/or when the
cut isnotbegun atfull throttle.
-'pu!!s the. saw forward, :and could cause the ==
operator to lose control.
=• •:
BEGIN CUTTING WITH THE
PUR AGAINST LOG.
Figure 26
B. TREE FELLING TECHNIQUES ....
. PLAN YOUR SAWING OPERATION CARE-
FULLY IN ADVANCE
a. Clear the work area. You needa clear area all
around the tree where you can have:secure
footing. '=: _
b. Studythe natural conditions that can cause
thetree to fall in a particular direction:
1 :) The WIND direction and speed
2.) The LEAN of thetree :
3.) WEIGHTED with BRANCHESon one side
4.) Surrounding TREES and OBSTACLES
c. Look for decay and r0t. Ifthe trunk is rotted,
itcould snap and falltoward the operator.
d. Check for broken or dead branches which
Could fall on you while cutting.
e: Make sure there is enough room for the tree
to fall. Maintaining a distance of 21/2 tree
lengths from the nearest person or other ob-
jects. Engine noise may drown out warning
carl.
f. Remove dirt, stones, loose bark, nails,
staples, and wire from the tree =where cuts
are to be made.
g. Plan to stand on the up-hill side when cut-
ting on a slope.
h. Plan a clear retreat path to the rear and
diagonal to the line of fall. Figure27.
14