Maintenance; Cleaning The Chain Saw; Sharpening The Saw Chain - Makita UC3541A Instruction Manual

Fig.25
− Cut a scarf: The scarf determines the direction in
which the tree will fall, and guides it. It is made on
the side towards which the tree is to fall. Cut the
scarf as close to the ground as possible. First
make the horizontal cut to a depth of 1/5 -1/3 of
the trunk diameter. Do not make the scarf too
large. Then make the diagonal cut.
− Cut any corrections to the scarf across its entire
width.
Fig.26
− Make the back cut a little higher than the base cut
of the scarf. The back cut must be exactly
horizontal. Leave approximately 1/10 of the trunk
diameter between the back cut and the scarf.
The wood fibers in the uncut trunk portion act as a
hinge. Do not cut right through the fibers under
any circumstances, as the tree will otherwise fall
unchecked. Insert wedges into the back cut in time.
− Only plastic or aluminum wedges may be used to
keep the back cut open. The use of iron wedges is
prohibited.
− Stand to the side of the falling tree. Keep an area
clear to the rear of the falling tree up to an angle of
45 ° either side of the tree axis (refer to the " felling
area " figure). Pay attention to falling branches.
− An escape path should be planned and cleared as
necessary before cuts are started. The escape
path should extend back and diagonally to the rear
of the expected line of fall as illustrated in figure.
Fig.27

MAINTENANCE

CAUTION:
Always be sure that the tool is switched off and
•
unplugged before attempting to perform inspection
or maintenance.
Always wear gloves
•
inspection or maintenance.
Never use gasoline, benzine, thinner, alcohol or
•
the like. Discoloration, deformation or cracks may
result.
Carry out the maintenance work described below at
regular intervals. Warranty claims will be accepted only
if these operations have been performed regularly and
properly.
Only maintenance work described in this instruction
manual may be performed by the user. Any other work
must be carried out by MAKITA authorized service
centers.

Cleaning the chain saw

Clean the saw regularly with a clean rag. The handles,
in particular, must be kept free of oil.
when performing any
Checking the plastic housing
Carry out regular visual inspections of all parts of the housing.
If any parts are damaged, have them repaired immediately
and properly in MAKITA authorized service centers.

Sharpening the saw chain

CAUTION:
Always withdraw the mains plug and wear safety
•
gloves when performing work on the saw chain.
Fig.28
Sharpen the saw chain when:
− Mealy sawdust is produced when damp wood is cut;
− The chain penetrates the wood with difficulty, even
when heavy pressure is applied;
− The cutting edge is obviously damaged;
− The saw pulls to the left or right in the wood. The
reason for this behavior is uneven sharpening of
the saw chain, or damage to one side only.
Sharpen the saw chain frequently, but remove only
a little material each time.
Two or three strokes with a file are usually sufficient for
routine resharpening. When the saw chain has been
resharpened several times, have it sharpened in
MAKITA authorized service center.
Sharpening criteria:
− All cutter length must be equal. Cutters of differing
length prevent the chain from running smoothly,
and may cause the chain to break.
− Do not sharpen the chain once a minimum cutter
length of 3 mm has been reached. A new chain
must then be fitted.
− The chip thickness is determined by the distance
between the depth gauge (round nose) and the
cutting edge.
− The best cutting results are obtained with following
distance between cutting edge and depth gauge.
Chain blade 90PX: 0.5 mm
Chain blade 91PX: 0.65 mm
Fig.29
WARNING:
An excessive distance increases the risk of kick-back.
•
− The sharpening angle of 30 ° must be the same on
all cutters. Differences in angle cause the chain to
run roughly and unevenly, accelerate wear, and
lead to chain breaks.
− The side plate angle of the cutter is determined by
the depth of penetration of the round file. If the
specified file is used properly, the correct side
plate angle is produced automatically.
− Side plate angle for each saw chain are as follows:
Chain blade 90PX: 75 °
Chain blade 91PX: 80 °
Fig.30
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