Maintenance - Makita BUC250 Bedienungsanleitung

Observe local regulations if you wish to fell a tree.
Fig.26
− Before starting felling work, ensure that:
(1) Only persons involved in the felling operation
are in the vicinity;
(2) Any person involved has an unhindered path
of retreat through a range of approximately
45 ° either side of the felling axis. Consider
the additional risk of tripping over electrical
cables;
(3) The base of the trunk is free of foreign
objects, roots and ranches;
(4) No persons or objects are present over a
distance of 2 1/2 tree lengths in the direction
in which the tree will fall.
− Consider the following with respect to each tree:
Direction of lean;
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Loose or dry branches;
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Height of the tree;
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Natural overhang;
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Whether or not the tree is rotten.
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− Consider the wind speed and direction. Do not
carry out felling work if the wind is gusting strongly.
− Trimming of root swellings: Begin with the largest
swellings. Make the vertical cut first, then the
horizontal cut.
Fig.27
− 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.28
− 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.
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Fig.29
Carrying tool
Fig.30
Always remove the battery cartridge from the tool and
overlap the guide bar with the scabbard before carrying
the tool. Also cover the battery cartridge with the battery
cover.

MAINTENANCE

CAUTION:
Always be sure that the tool is switched off and the
•
battery cartridge is removed before attempting to
perform inspection or maintenance.
Always wear gloves
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inspection or maintenance.
Never use gasoline, benzine, thinner, alcohol or
•
the like. Discoloration, deformation or cracks may
result.
Sharpening the saw chain
CAUTION:
Always remove the battery cartridge and wear
•
safety gloves when performing work on the saw
chain.
Fig.31
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 behaviour 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 a
MAKITA specialist repair shop.
File and file guiding
− Use a special round file (optional accessory) for
saw chains, with a diameter of 4 mm, to sharpen
the chain. Normal round files are not suitable.
13
when performing any