side than on the other. To
get a more even result, try to
maintain the same working
position when ling the left
and the right sides of the
chain. That individual cutters
are faulty or that some are
missing, such as after sawing
through nails, usually has very
small effect on the function.
4. W h e n p r e c i s i o n
diminishes after a period of
fault-free sawing, it is almost
always due to wear on the
guide bar (see page 31).
Tensions in the wood can
sometimes result in similar
symptoms as faults in the
cutting equipment.
C. Tensions in the
wood
The M7 sawmill can only
saw straight. If the wood
grain twists during sawing,
precision will be lost. Tension
can cause large variations
in measurement. Broad
leaved trees have greater
tension than do evergreens,
but even the latter can have
problematic tensions. One
example is in trees that have
grown on sharp inclines. In
such cases a whole group of
logs can be hard to saw.
Tensions can also arise in
storage. If the bark and top
segment begin to dry, the
whole surface will begin to
shrink. In such a case, when
one side is trimmed, the log
may bend slightly.
I t i s e a s y t o d i s c o v e r
tension in logs that leads
to measurement errors.
Each time you pull the saw
back, you can read what is
happening in the log. As long
as the guide bar continues
to lie just above the newly
sawn surface, the log has
not bent. However, if spaces
show up between the guide
bar and the sawn surface or
if the guide bar is pressed
upwards, it is time to plan how
the next cut will go to reduce
the tensions.
When sawing from the top
towards the bottom, the wood
has a tendency to sink at the
ends pulled by its own weight.
This is especially true if there
is large root-end growth. If this
is true, then it would be best
to turn the log after passing
through the centre and saw
the rest of the material from
the other side.
Some tips for avoiding
the effects of wood
tensions.
1. Cut wood with tension
in as short lengths as possible.
By reducing the log length
to app. 2.5 m (8.2 ft) the
precision will be high even if
there is great tension in the
wood.
2. Work around the log,
sawing all sides in order.
3. Special arrangements
may be needed in order to get
29
a perfect measurement on the
last board of a long log. One
effective way is to saw the last
cuts using a recently sawn
board as support. Another
way is to use one of the
special accessories designed
for the M7 to support the
ends of long logs (articulated
support, part. no. 4500-070-
1000; adjustable log support,
part. no. 4510-720-6102). If
many logs over 5 m (16.5
ft) are to be sawn, it is best
to extend the sawmill by 2
m (6.5 ft) and one extra log
bed (F820, part. no. 4507-
010-0820) in order to obtain
additional support.
There is no limit to how far
the Logosol M7 sawmill can
be extended.
When the bar is not tted
straight
On some chainsaws the bar
tting is not level, making the
bar tilted sideways. Clean the
bar tting. Place a straight
and approx. 1 m (3.3 ft) long
board across the bar (without
the chain). Measure the dis-
tance between the upper side
of the guide rail and each end
of the board. If the bar is tilted
sideways, place thin strips of
metal (e.g. 1-3 layers of strips
from an aluminium soda can)
between the bottom plate of
the carriage and the alumi-
nium slide proles until the
board is parallel to the guide
rail. (For electric saws, read
The Handbook for Your Cut-
ting Equipment, which you
can nd on our website.)
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