Jonsered 625 Chainsaw User Manual


 
22 – English
SAFETY INSTRUCTIONS
C Clearing the trunk and preparing your retreat
Remove any branches that
are in the way. To do this it is
best to work from the top
down and keep the trunk
between you and the chain
saw. Never limb above
shoulder height.
Remove any undergrowth
from the base of the tree and
check the area for obstacles
(stones, branches, holes, etc.)
so that you have a clear path
of retreat when the tree starts
to fall. Your path of retreat
should be roughly 135
degrees behind the intended
felling direction.
D Felling
Felling is done using three cuts. First you make the
DIRECTIONAL CUTS, which consist of the TOP CUT and the
BOTTOM CUT; followed by the FELLING CUT. By placing
these cuts correctly you can control the felling direction very
accurately.
DIRECTIONAL CUT
To make the DIRECTIONAL
CUT you begin with the TOP
CUT. Stand to the right of the
tree and cut downwards at an
angle.
Next make the BOTTOM CUT
so that it finishes at the end of
the TOP CUT.
The directional cut should run
1/4 of the diameter through
the trunk and the angle
between the TOP CUT and
BOTTOM CUT should be 45°.
The line where the two cuts
meet is called the
DIRECTIONAL CUT LINE.
This line should be perfectly
horizontal and at right angles
(90°) to the chosen felling
direction.
FELLING CUT
The felling cut is made from the opposite side of the tree and it
must be perfectly horizontal. Stand on the left side of the tree
and cut with the bottom edge of the bar.
Make the FELLING CUT
about 3-5 cm (1.5-2 inches)
above the flat section of the
DIRECTIONAL CUT.
Set the spike bumper in
behind the breaking strip (if
one is fitted).Use full throttle
and bring the bar and chain
slowly into the tree. Make sure
the tree does not start to
move in the opposite direction
to your intended felling
direction. Drive a WEDGE or
BREAKING BAR into the cut
as soon as it is deep enough.
Finish the FELLING CUT
parallel with the
DIRECTIONAL CUT LINE so
that the distance between
them is at least at least 1/10
of the trunk diameter. The
uncut section of the trunk is
called the BREAKING STRIP.
The BREAKING STRIP act as
hinges that control the felling
direction of the falling tree.
All control over the felling
direction is lost if the BREA-
KING STRIP is too narrow or
if the directional cut and felling
cut are badly placed.
When the felling cut and
directional cut are complete
the tree should start to fall
under its own weight or with
the aid of a FELLING WEDGE
or BREAKING BAR.