Sears 358.356090-3.7/20, 358.356100-3.7/18"PS Tree Felling Techniques, Understand Reactive Forces

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

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.

mPROCEDURE

small amount		of dirt will quickly dull a Chain and		Practice cutting a few smalt logs using the follow-
thus, increase the possibility			of kickback.	ing technique	to get the '_eel" of using your		saw
2. UNDERSTAND		REACTIVE	FORCES	before you begin a major sawing operation.
				a. Accelerate	the engine to full throttle	just	be-
Pushback	and	Pull-in occur when the chain is		fore entering the cut by squeezing		the Throt-
suddenly	stopped by being		pinched, caught,	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 in the op-

c.

Keep

the engine

at full

throttle

the entire

posite

direction

of

chain

rotation,

resulting in loss

time you are cutting.

of control and possible serious

personal injury.:'.

d.

Allow the chain to Cut foryou; exert only light

'e Pushback:

downward pressure. If you force the cut, dam-

age to the bar, chain or eng_ne can result.

--occurs

when the chain

on top of the bar, is sud-

e. Release the throttle trigger as soon as the

deftly stopped When the top of the bar is used for

cut is completed, allowing the engine to idle.

cutting.

If you run the saw at full throttle without a cut-

.... drives the saw straigl_t back toward the operator,

ting load, unnecessary wear can occur to the

poss!bly causingloss of saw control.

chain, bar, and engine.

To avoid Pushback:

f.

Do not put pressure oh the saw

at the end

a.

Be

extremely

aware

of

situations

or

of the cut to avoid Iosing control when the cut

obstructions

that may cause material to stop

iscomplete.

or pinch the top of the chain.

g.

Stop

the engine

before

setting

the saw

....b.

Do not cut more than one log at a time.

down after cutting.

c.Do not twist the saw as the bar is withdrawn =" from an under-cut_

ePull-in:

R occurs when the chain on the bottom of the bar

is suddenly stopped.

--occurs when the spike orsaw housing is not held securely against the tree or limb and/or when the cut is not begun at full 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. If the trunk is rotted, itcould snap and fall toward 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.

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