Makita Maktec MT920 Manual

Model No.
Description
PRODUCT
CONCEPT AND MAIN APPLICATIONS
P 1 /5
Specification
Standard equipment
Optional accessories
Note: The standard equipment for the tool shown above may differ by country.
MT920
Finishing Sander
Model MT920 has been developed as the first maktec palm sander, featuring:
Slim grip for easy horizontal and overhead applications
Industrial performance and durability at less expense
H
W
Dimensions: mm (")
Width (W)
Height (H)
Length (L) 110 (4-5/16)
112 (4-3/8)
133 (5-1/4)
Continuous Rating (W)
Voltage (V) Cycle (Hz) Input Output
25
Max. Output (W)
110
220
240
1.7
0.9
0.8
50/60
50/60
50/60
180
180
180
50
50
50
Current (A)
25
25
Pad size: mm (") 112 x 102 (4-3/8 x 4)
Double insulation
Net weight: kg (lbs)
Power supply cord: m (ft)
Abrasive paper size: mm (") 114 x 140 (4-1/2 x 5-1/2)
Yes
2.0 (6.6)
0.9 (2.0)
Orbits per minute: min.-1= opm 14,000
Strokes per minute: min.-1= spm 28,000
Abrasive paper 114-60 ....................... 2 pcs
Abrasive paper 114-100 ..................... 2 pcs
Abrasive paper 114-150 ..................... 2 pcs
Abrasive paper 114-60
Abrasive paper 114-80
Abrasive paper 114-100
Abrasive paper 114-150
L
TECHNICAL INFORMATION

P 2 /5
[2] LUBRICATION
[3] DISASSEMBLY/ASSEMBLY
[Armature]
Lubrication is not required for this product because no gear is used for transmission.
1) Remove Base and Fan 65 from Armature as illustrated in Figs. 1, 2, 3.
[1] NECESSARY REPAIRING TOOLS
CAUTION: Unplug the machine for safety before repair/ maintenance,
in accordance with the instruction manual!
1R027 Bearing setting pipe 18-10.2 Removing Armature from Bearing box
Removing Ball bearings from Armature1R269 Bearing extractor
Repair
Locking Fan 65 with a slotted screwdriver or the like,
remove M4x10 +Countersunk head screw and Flat washer 6.
Fan 65 and Base can now
be removed from Armature.
Remove Pad complete by unscrewing four
M4x10 +Pan head screws.
Remove Top cover by unscrewing three
M4x20 Pan head screws, then disconnect
Carbon brush from Armature commutator.
Flat washer 6
Fan 65
Fan 65
Fig. 1 Fig. 2
Fig. 3
Base
Ball bearing 6001ZZ
DISASSEMBLING
DescriptionCode No. Use for
Pan head screw
M4x20 (3 pcs)
+ Pan head screw
M4x10 (4 pcs)
Pad complete
Top cover
Carbon brush
(with Brush holder) +Countersunk head screw
M4x10

P 3 /5
[3] DISASSEMBLY/ASSEMBLY
[Armature] (cont.)
2) Remove four 4x18 Tapping screws. Disassemble Armature from Motor housing together with Bearing box by
tapping the end surface of Motor housing with plastic hammer as illustrated in Fig. 4.
3) Disassemble Armature from Bearing box using 1R027 and arbor press. (Fig. 5)
4) Remove Ball bearing 606ZZ from the commutator-end of Armature shaft using 1R269 and adjustable pliers, (Fig. 6)
Note: Be sure to firmly grasp the claws of 1R269 with adjustable pliers because the space between Insulation washer
and Ball bearing 606ZZ is so tight that Ball bearing 606ZZ cannot be securely grasped with the claws of 1R269.
5) Remove Ball bearing 629ZZ from the drive-end of Armature shaft using 1R269 and adjustable pliers in the same way
as described above in 4). (Fig. 7)
Important: Before attaching 1R269 to Ball bearing 629ZZ, be sure to fasten M4x10 +Countersunk head screw to
the drive-end of Armature shaft in order not to damage to the threads inside Armature shaft.
Repair
Bearing box
Armature
1R027
Fig. 5
Fig. 6 Fig. 7
Tapping screw
bind 4x18 (4 pcs) Bearing box Armature
Motor housing
Fig. 4
Ball bearing 629ZZ
Washer 9
Ball bearing 606ZZ
Insulation washer
DISASSEMBLING
1R269
adjustable pliers
+Countersunk head
screw M4x10

P 4 /5
[3] DISASSEMBLY/ASSEMBLY
[Armature]
Repair
Do the reverse of the disassembling steps.
Note: Washer 9 is not reversible when assembled to
the drive-end of Armature shaft.
Be sure to place its convex side on Fan 65 side
as illustrated in Fig. 8.
ASSEMBLING
Ball bearing 629ZZ
Washer 9
Fan 65
Convex side
Bearing box
drive-end of
Armature shaft
Fig. 8

Circuit diagram
Wiring diagram
P 5 /5
Terminal block
Noise suppressor*
Fig. 9
Fig. 10
Field
Switch
Power supply cord
Color index of lead wires' sheath
Black
White
*Noise suppressor is not used
for some countries.
Brown for some countries
Blue for some countries
opening 1
Noise suppressor (if used)
Terminal block
Power supply cord
Switch
Brush
holder
Strain relief
Lead wire holder 1
Lead wire holders 2, 3
groove
space 1
space 2
Route Lead wires as illustrated in Fig. 10.
1 4 Field lead wire (black):
Route through the opening 1/opening 2 of
Motor housing, then connect to Brush holder.
Note: Be sure to fix with Lead wire holder 1/
Lead wire holder 6.
2 Field lead wire (white):
Route through the opening 1 of Motor housing,
then connect to Switch.
Note: Be sure to fix with Lead wire holders 2, 3.
3 Lead wire of Noise suppressor (white):
Connect to Switch.
Note: Be sure to fix with Lead wire holders 4, 5.
5 Field lead wire (white):
Route through the opening 2 of Motor housing,
then connect to Terminal block.
6 Lead wire (white) of Noise suppressor:
Connect to Terminal block.
7 Lead wire (white or blue) of Power supply cord:
Connect to Terminal block.
8 Lead wire (black or brown) of Power supply cord:
Connect to Switch.
Note: Be sure to route through the groove of Motor housing.
Note: Put slack portions of Lead wires in spaces 1 and 2.
2
4
1
3
7
8
6
opening 2
Lead wire holders 4, 5
Lead wire holder 6
5
[Motor housing viewed from top]
Brush holder Brush holder