WORKING TECHNIQUES
24 – English
7
Take great care when you cut with the top edge of the
bar, i.e. when cutting from the underside of the object.
This is known as cutting with a pushing chain. The
chain tries to push the chain saw back towards the
user. If the saw chain is jamming, the saw may be
pushed back at you.
8
Unless the user resists this pushing force there is a
risk that the chain saw will move so far backwards that
only the kickback zone of the bar is in contact with the
tree, which can lead to a kickback.
Cutting with the bottom edge of the bar, i.e. from the
top of the object downwards, is known as cutting with
a pulling chain. In this case the chain saw pulls itself
towards the tree and the front edge of the chain saw
body rests naturally on the trunk when cutting. Cutting
with a pulling chain gives the operator better control
over the chain saw and the position of the kickback
zone.
9
Follow the instructions on sharpening and maintaining
your bar and chain. When you replace the bar and
chain use only combinations that are recommended
by us. See instructions under the headings Cutting
equipment and Technical data.
Basic cutting technique
General
•
Always use full throttle when cutting!
•
Reduce the speed to idle after every cut (running the
engine for too long at full throttle without any load, i.e.
without any resistance from the chain during cutting,
can lead to serious engine damage).
•
Cutting from above = Cutting with a pulling chain.
•
Cutting from below = Cutting with pushing chain.
Cutting with a pushing chain increases the risk of
kickback. See instructions under the heading How to
avoid kickback.
Terms
Cutting = General term for cutting through wood.
Limbing = Cutting branches off a felled tree.
Splitting = When the object you are cutting breaks off
before the cut is complete.
There are five important factors you should consider
before making a cut:
1
Make sure the cutting equipment will not jam in the
cut.
2
Make sure the object you are cutting will not split.
3
Make sure the chain will not strike the ground or any
other object during or after cutting.
4
Is there a risk of kickback?
5
Do the conditions and surrounding terrain affect how
safely you can stand and move about?
Two factors decide whether the chain will jam or the object
that you are cutting will split: the first is how the object is
supported before and after cutting, and the second is
whether it is in tension.
In most cases you can avoid these problems by cutting in
two stages; from the top and from the bottom. You need to
support the object so that it will not trap the chain or split
during cutting.
The following instructions describe how to handle the
common situations you are likely to encounter when using
a chain saw.
!
WARNING! Never use a chain saw by
holding it with one hand. A chain saw is
not safely controlled with one hand.
Always have a secure, firm grip around
the handles with both hands.
IMPORTANT! If the chain jams in the cut: stop the
engine! Don’t try to pull the chain saw free. If you do you
may be injured by the chain when the chain saw
suddenly breaks free. Use a lever to open up the cut and
free the chain saw.
Summary of Contents for CS 2152 EPA III
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