Jonsered 670 - Manual (Page 12)

12
– English
SAFETY INSTRUCTIONS
!
2 Sharpening your chain and adjusting
raker clearance
The risk of kickback is increased with a badly
sharpened chain!
A General information on sharpening cutting teeth
• Never use a blunt chain. When the chain is blunt you have to
exert more pressure to force the bar through the wood and
the cuttings will be very small. If the chain is very blunt it will
not produce any cuttings at all, just wood powder.
• A sharp chain eats its way
through the wood and
produces long, thick
cuttings.
• The cutting part of the chain
is called the CUTTING LINK
and this consists of a
CUTTING TOOTH (A) and
the RAKER LIP (B). The
cutting depth is determined
by the difference in height
between the two.
• When you sharpen a cutting tooth there are five important
factors to remember.
FILING ANGLE
CUTTING ANGLE
FILE POSITION
ROUND FILE DIAMETER
FILE DEPTH
See the ”Technical data” section for information about
sharpening your saw chain.
!
It is very difficult to sharpen a
chain correctly without the
right equipment. We
recommend you use a file
gauge. This will help you
obtain the maximum kickback
reduction and cutting
performance from your chain.
The following faults will increase the risk of
kickback considerably.
• FILE ANGLE TOO
LARGE
• CUTTING ANGLE
TOO SMALL
• FILE DIAMETER
TOO SMALL
B Sharpening cutting
teeth
To sharpen cutting teeth you
will need a ROUND FILE and
a FILE GAUGE. See the
”Technical data” section for
information on the size of file
and gauge that are
recommended for your saw
chain.
1 Check that the chain is
correctly tensioned. A
slack chain is difficult to
sharpen correctly.
2 Always file cutting teeth
from the inside face,
reducing the pressure on
the return stroke.
File all the teeth on one
side first, then turn the
saw over and file the
teeth on the other side.
3 File all the teeth to the
same length. When the
length of the cutting teeth
is reduced to 4 mm
(0,16") the chain is worn
out and should be
replaced.
B
A
1
5
min 4 mm
(0,16")