Makita UC3020A Manual De Instrucciones página 13

Checking the chain oiler (Fig. 21)
Before starting work, check the oil level in the tank, and
the oil delivery.
The oil level can be seen in the sight glass shown in the
figure.
Check the oil delivery as follows:
Start the chain saw.
With the saw running, hold the saw chain approximately
15 cm above a tree trunk or the ground. If lubrication is
adequate, the oil spray will produce a light oil trace.
Observe the wind direction, and do not expose yourself to
the oil spray unnecessarily.
CAUTION:
• If an oil trace is not formed, do not use the saw. The
lifespan of the chain will otherwise be reduced. Check
the oil level. Clean the oil feed groove and the oil feed
hole in the bar (refer to "MAINTENANCE").
WORKING WITH THE CHAIN SAW
Bucking
For bucking cuts, rest the serrated rail shown in the figure
on the wood to be cut. (Fig. 22)
With the saw chain running, saw into the wood, using the
rear handle to raise the saw and the front one to guide it.
Use the serrated rail as a pivot.
Continue the cut by applying slight pressure to the front
handle, easing the saw back slightly. Move the serrated
rail further down the timber and raise the front handle
again.
When making several cuts, switch the chain saw off
between cuts.
CAUTION:
• If the upper edge of the bar is used for cutting, the
chain saw may be deflected in your direction if the
chain becomes trapped. For this reason, cut with the
lower edge, so that the saw will be deflected away from
your body. (Fig. 23)
Cut wood under tension on the pressure side (A) first.
Then make the final cut on the tension side (B). This pre-
vents the bar from becoming trapped. (Fig. 24)
Limbing
CAUTION:
• Limbing may only be performed by trained persons. A
hazard is presented by the risk of kick-back.
When limbing, support the chain saw on the trunk if possi-
ble. Do not cut with the tip of the bar, as this presents a
risk of kickback.
Pay particular attention to branches under tension. Do not
cut unsupported branches from below.
Do not stand on the felled trunk when limbing.
Burrowing and parallel-to-grain cuts
CAUTION:
• Burrowing and parallel-to-grain cuts may only be car-
ried out by persons with special training. The possibility
of kickback presents a risk of injury.
Perform parallel-to-grain cuts at as shallow an angle as
possible. Carry out the cut as carefully as possible, as the
serrated rail cannot be used. (Fig. 25)
Felling
CAUTION:
• Felling work may only be performed by trained per-
sons. The work is hazardous.
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 addi-
tional 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;
• Loose or dry branches;
• Height of the tree;
• Natural overhang;
• Whether or not the tree is rotten.
- 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 swel-
ings. 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
scarf in time.
- Only plastic or aluminum wedges may be used to keep
the scarf 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" fig-
ure). Pay attention to falling branches.
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