Stihl MS 150 C Instruction Manual page 16

English
Backcutting principles
Basic dimensions
C
C E
The felling notch (C) determines the
direction of fall.
The hinge (D) functions like a real hinge
to guide the tree to the ground.
Width of hinge: approx. 1/10 of the
–
trunk diameter
Never saw through the hinge while
–
felling – otherwise the tree will fall in
a direction other than the one
planned – risk of accident!
With rotten trunks, leave a wider
–
hinge
The tree is felled with the backcut (E).
Exactly horizontal
–
1/10 (min. 3 cm) of the width of the
–
hinge (D) across the bottom of the
felling notch (C)
14
The holding wood (F) or safety strip (G)
supports the tree and secures it against
premature falling.
Width of strip: approx. 1/10 to 1/5 of
–
the trunk diameter
Do not cut into the strip during the
–
backcut
With rotten trunks, leave a wider
–
strip
1/10
D
Plunge cutting
For relieving cuts during bucking
–
For wood carving
–
G
1.
Use a low kickback chain and be
N
especially cautious
1. Begin the cut by applying the lower
portion of the guide bar tip – do not
use the upper portion – risk of
kickback! Cut at full strength until
the depth of the kerf is twice the
width of the guide bar
3.
2.
2. Swing the machine slowly into the
plunge cutting position – risk of
kickback and pushback!
3. Make the plunge cut very carefully –
danger of pushback!
Where possible, use a plunge blade.
The plunge blade and the upper/lower
side of the guide bar are parallel.
During plunge cutting, the plunge bar
helps to keep the hinge parallel in form,
i.e. the same thickness at all points. To
do this, guide the plunge bar parallel to
the sink chord.
Felling wedges
Insert the felling wedge as soon as
possible, i.e. as soon as saw control
cannot be hindered. Position the felling
wedge in the backcut and drive in with
suitable tools.
Only use aluminium or plastic wedges –
do not use steel wedges. Steel wedges
can seriously damage the saw chain and
cause dangerous kickback.
Select suitable felling wedges
dependent on the trunk diameter and the
width of the kerf (analogue to backcut
(E)).
Contact the STIHL servicing dealer for
the selection of the felling wedge
(suitable length, width and height).
MS 150 C