Maintenance - Maktec MT903 Betriebsanleitung

Grinding and sanding operation
ALWAYS hold the tool firmly with one hand on rear han-
dle and the other on the side handle. Turn the tool on and
then apply the wheel or disc to the workpiece.
In general, keep the edge of the wheel or disc at an angle
of about 15 degrees to the workpiece surface.
During the break-in period with a new wheel, do not work
the grinder in the B direction or it will cut into the work-
piece. Once the edge of the wheel has been rounded off
by use, the wheel may be worked in both A and B direc-
tion. (Fig. 8)
Operation with wire cup brush
(optional accessory) (Fig. 9)
CAUTION:
• Check operation of brush by running tool with no load,
insuring that no one is in front of or in line with brush.
• Do not use brush that is damaged, or which is out of
balance. Use of damaged brush could increase poten-
tial for injury from contact with broken brush wires.
Unplug tool and place it upside down allowing easy
access to spindle. Remove any accessories on spindle.
Mount wire cup brush onto spindle and tighten with sup-
plied wrench. When using brush, avoid applying too
much pressure which causes over bending of wires,
leading to premature breakage.
Operation with wire wheel brush
(optional accessory) (Fig. 10)
CAUTION:
• Check operation of wire wheel brush by running tool
with no load, insuring that no one is in front of or in line
with the wire wheel brush.
• Do not use wire wheel brush that is damaged, or which
is out of balance. Use of damaged wire wheel brush
could increase potential for injury from contact with bro-
ken wires.
• ALWAYS use guard with wire wheel brushes, assuring
diameter of wheel fits inside guard. Wheel can shatter
during use and guard helps to reduce chances of per-
sonal injury.
Unplug tool and place it upside down allowing easy
access to spindle. Remove any accessories on spindle.
Thread wire wheel brush onto spindle and tighten with
the wrenches.
When using wire wheel brush, avoid applying too much
pressure which causes over bending of wires, leading to
premature breakage.
Operation with abrasive cut-off / diamond wheel
(optional accessory) (Fig. 11)
WARNING:
• When using an abrasive cut-off / diamond wheel, be
sure to use only the special wheel guard designed for
use with cut-off wheels.
• NEVER use cut-off wheel for side grinding.
• Do not "jam" the wheel or apply excessive pressure. Do
not attempt to make an excessive depth of cut. Over-
stressing the wheel increases the loading and suscepti-
bility to twisting or binding of the wheel in the cut and
the possibility of kickback, wheel breakage and over-
heating of the motor may occur.
• Do not start the cutting operation in the workpiece. Let
the wheel reach full speed and carefully enter into the
cut moving the tool forward over the workpiece surface.
The wheel may bind, walk up or kickback if the power
tool is started in the workpiece.
• During cutting operations, never change the angle of
the wheel. Placing side pressure on the cut-off wheel
(as in grinding) will cause the wheel to crack and break,
causing serious personal injury.
• A diamond wheel shall be operated perpendicular to
the material being cut.
Mount the inner flange onto the spindle. Fit the wheel/
disc on the inner flange and screw the lock nut onto the
spindle.
When installing a diamond wheel or a abrasive cut-off
wheel with its 7 mm or more thick wheel body, mount the
lock nut with its pilot circular part (protrusion) for wheel
bore facing the wheel.
For Australia and New Zealand
Installing or removing abrasive cut-off wheel /
diamond wheel (optional accessory) (Fig. 12)

MAINTENANCE

CAUTION:
• Always be sure that the tool is switched off and
unplugged before attempting to perform inspection or
maintenance.
• Never use gasoline, benzine, thinner, alcohol or the
like. Discoloration, deformation or cracks may result.
The tool and its air vents have to be kept clean. Regularly
clean the tool's air vents or whenever the vents start to
become obstructed. (Fig. 13)
Replacing carbon brushes (Fig. 14 & 15)
When the resin insulating tip inside the carbon brush is
exposed to contact the commutator, it will automatically
shut off the motor. When this occurs, both carbon
brushes should be replaced. Keep the carbon brushes
clean and free to slip in the holders. Both carbon brushes
should be replaced at the same time. Use only identical
carbon brushes.
Use a screwdriver to remove the brush holder caps. Take
out the worn carbon brushes, insert the new ones and
secure the brush holder caps.
To maintain product SAFETY and RELIABILITY, repairs,
any other maintenance or adjustment should be per-
formed by Makita Authorized Service Centers, always
using Makita replacement parts.
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