Ryobi CS-1840, Owner'S Operating Manual

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Chain Brake (Fig.10)
In the event of kick-back, the chain brake will be actuated
via the front finger guard. The front finger guard is pushed
forwards by the back of the hand and this causes the chain
brake to stop the chain saw, or rather the motor, within
0.15 seconds.
Releasing The Chain Brake (Fig.11)
To be able to use your chain saw again, you must release
the saw chain. First switch off the chain saw. Then push
the front finger guard back into the vertical position until
it locks in place. The chain brake is now fully functional
again.
Proper Grip On Handles (Fig.12)
Always grip both handles with the thumbs and fingers
encircling the handles. Ensure that your left hand is holding
the handle so that the thumb is underneath.
WARNING! Always start a cut next to the claw stop at the
base of the guide bar.
Using The Chain Saw (Fig.13)
1. Switch on the chain saw. Place the lowest claw on the
wood.
2. Lower the chain saw by raising the rear grip and saw
into the wood.
3. Move the chain saw back a little and place the claw
further down.
4. Be careful when sawing splintered wood as pieces of
wood may be ripped off.
Tips On Chain Saw Use
To saw up wood, please observe the safety regulations
and proceed as follows:
• The chain saw must be running before it comes into
contact with the wood.
• Make sure the wood to be sawed cannot slip. Clamp
short pieces of wood in place before sawing.
• Saw only wood or wooden objects.
• When sawing, make sure that no stones or nails are
touched as these could be thrown out and damage the
chain saw or cause serious injury.
• Avoid touching the running saw on wire fences or the
ground.
• When lopping off branches, support the chain saw as far
as possible and do not saw with the tip of the guide bar.
• Ensure you have a firm footing at all times. Watch out
for obstacles such as tree stumps; roots; ditches; and
hillocks as these could cause you to fall.
• You can avoid accidents by not sawing with the tip of the
guide bar as this may cause the saw to rear up suddenly.
This is known as kickback. Kickback is an upward and/
or backward movement of the guide bar which can occur
if the saw chain at the tip of the guide bar encounters
an obstruction. Kickback causes the saw to behave
uncontrollably. A poorly sharpened or loosely tensioned
chain increases the risk of kickback.
• Make sure your workpiece is firmly secured to stop the
workpiece slipping. Wherever possible, clamp the wood
in place before sawing. This makes it easier to operate
the chainsaw with both hands.
Top side of wood under tension: Wood will spring up
Bottom side of wood under tension: Wood will spring
downwards
Thick trunks and high tension: Tree will move suddenly
with immense force.
Both sides of trunk under tension: Tree will move
sideways.
Felling Trees (Fig. 14)
WARNING!
Felling trees is dangerous and requires
practice. If you are a beginner or inexperienced, do not try
to teach yourself but seek professional training.
• Falling trees can bring down other trees with them. The
DANGER ZONE is therefore twice the height of the tree
being felled. Therefore when logging felled trees and
felling operations are being performed simultaneously
by two or more operators, the felling operation should be
separated from the logging operation by a distance of at
least twice the height of the tree being felled.
• Trees should not be felled in a manner that would
endanger any person, strike any utility line or cause any
property damage. If the tree does make contact with
any utility line, the utility company should be notified
immediately.
• The chain saw operator should keep on the uphill side
of the terrain as the tree is likely to roll or side downhill
after it is felled.
• If the saw chain gets jammed, release it using a wooded
wedge.
WARNING! The chain saw may only be used to fell trees
which are smaller in diameter than the length of the guide
bar.
• Before felling is started consider the natural lean of
the tree, the location of larger branches and the wind
direction to judge which way the tree will fall.
• Remove dirt, stones, loose bark, nails, staples and wire
from the tree before felling cuts are to be made.
• A retreat path should be planned and cleared as
necessary before cuts are started. The retreat path
should extend back and diagonally to rear of the
expected line of fall as illustrated.
Notching Undercut (Fig. 15)
A notching undercut is a notch cut in a tree to direct the fall
of the tree.
First estimate the direction of fall, taking into account the
center of gravity of the crown and the wind direction. Saw
an under cut in the tree in the direction of fall. Make the
notch 1/3 the diameter of the tree, perpendicular to the
direction of fall.
Make the lower horizontal notching cut first, this will help
to avoid pinching of either the saw chain or the guide bar
when the second cut is being made.
Felling Back Cut (Fig. 16)
A felling back cut is the final cut in a tree felling operation,
made on the opposite side of the tree from the notching
undercut.
Make the felling back cut at least 50mm higher than the
Wood Under Tension
One must be very careful when sawing wood/trees which
are under tension as there are much dangerous involved.