-35-
workpieces can get wedged under the parallel stop
and lead to backlash.
3.3
Backlash - Reasons and corresponding
safety instructions
A backlash is the sudden reaction of the workpiece as
a result of a hooked, clamping saw blade or an
oblique cut into the workpiece with respect to the saw
blade. It can also occur if a part of the workpiece is
jammed between the saw blade and the parallel stop
or another stationary object.
In most cases, in the event of a backlash, the
workpiece is caught by the rear part of the saw blade,
lifted off the saw bench and hurled in the direction of
the operator.
A backlash is the result of a wrong or incorrect use of
the circular saw bench. It can be prevented by taking
suitable precautions, as described below.
-
Never stand in a direct line with the saw blade.
Always hold on to the side of the saw blade on
which the stop rail is located. In the event of a
backlash, the workpiece can be hurled at high
speed onto persons standing in front of and in line
with the saw blade.
-
Never reach over or behind the saw blade to
pull or support the workpiece. Accidental
contact with the saw blade may occur, or a
backlash may cause your fingers to be pulled into
the saw blade.
-
Never hold and press the workpiece that is to
be cut off against the rotating saw blade.
Pressing the workpiece that is to be cut off against
the saw blade leads to jamming and backlash.
-
Align the stop rail parallel to the saw blade. A
non-aligned stop rail presses the workpiece
against the saw blade and creates a backlash.
-
For concealed saw cuts (e.g. seaming,
grooving or splitting using the reversal
process), use a feather board to guide the
workpiece against the bench and stop rail. With
a feather board, you can better control the
workpiece in the event of a backlash.
-
Be particularly careful when sawing in non-
visible areas of assembled workpieces. The
plunging saw blade can cut into objects that can
cause a backlash.
-
Support large boards to reduce the risk of
backlash caused by a jammed saw blade. Large
boards can bend under their own weight. Boards
must be supported wherever they project beyond
the bench surface.
-
Be
particularly
careful
when
sawing
workpieces that are twisted, knotted, warped,
or do not have a straight edge along which
they can be guided with a mitre stop or along a
stop rail. A twisted, knotted or warped workpiece
is unstable and leads to misalignment of the saw
kerf with the saw blade, jamming and backlash.
-
Never saw several workpieces stacked on top
of each other or behind each other. The saw
blade could seize one or more parts and cause a
backlash.
-
If you would like to restart a saw, the blade of
which is stuck in the workpiece, centre the saw
blade in the saw kerf so that the saw teeth are
not stuck in the workpiece. If the saw blade gets
stuck, it can lift the workpiece or cause a backlash
when the saw is restarted.
-
Keep saw blades clean, sharp and adequately
set. Never use warped saw blades or saw
blades with cracked or broken teeth. Sharp and
correctly set saw blades minimise jamming,
blocking and backlash.
3.4
Safety instructions for the operation of
circular saw benches
-
Turn off the circular saw and disconnect it from
the power supply before removing the bench
insert, changing the saw blade, adjusting the
riving knife/splitter or the protective cover of
the saw blade, and when leaving the machine
unattended. Precautions aim to prevent accidents.
-
Never let the circular saw bench run
unattended. Switch off the power tool and do
not leave it until it has come to a complete
stop. A saw running unattended poses an
uncontrolled hazard.
-
Children and adolescents must not operate this
machine. This rule does not apply to young
