Maktec MT902 Manual

Specification
Standard equipment
Dimensions: mm (")
Width (W)
Height (H)
Length (L)
Model No. MT902 MT903
466 (18-3/8)
200 (7-7/8) 250 (9-7/8)
138 (5-7/16)
Note: The standard equipment for the tool shown above may vary by country.
Models MT902 and MT903 have been developed as the aesthetic
change models of maktec angle grinders MT900 and MT901.
Feature the same advantages the current models as follows:
Anti-dust, heavy-duty 2,000W motor
Industrial performance and durability at less expense
High dust-proof construction
Rear handle with anti-slip surface for more control
Machined spiral bevel gear for durability and long
service life of the machine
Lock nut wrench ................ 1 pc.
Side grip ............................. 1 pc.
Model No.
No load speed: min.-1 = rpm
Diameter
Hole diameter
Wheel size: mm (")
Protection against electric shock
Power supply cord: m (ft)
Net weight*: kg (lbs)
MT902 MT903
180 (7) 230 (9)
2.0 (6.6)
5.4 (12.0) 5.7 (12.6)
8,500 6,600
Double insulation
22.23 (7/8)
Continuous Rating (W)
Voltage (V) Cycle (Hz) Input Output Max. Output (W)
120
110 15 1,650
---
1,100 2,70050/60
9.6 2,000 1,400 3,00050/60
8.8 2,000 1,400 3,00050/60
15 1,100 2,70050/60
220
9.2 2,000 1,400 3,00050/60230
240
Current (A)
Optional accessories
MT902: Accessories for 180mm angle grinder
MT903: Accessories for 230mm angle grinder
*Weight according to EPTA-Procedure 01/2003, with Side grip, Wheel cover, Inner flange, Lock nut
Model No.
Description
MT902, MT903
Angle Grinders 180mm (7")/ 230mm (9")
CONCEPT AND MAIN APPLICATIONS
L
H
W
P 1/ 9
PRODUCT
TECHNICAL INFORMATION

P 2/ 9
Repair
CAUTION: Repair the machine in accordance with “Instruction manual” or “Safety instructions”.
[1] NECESSARY REPAIRING TOOLS
[2] LUBRICATIONS
[3] DIFFERENCE OF GEARS BETWEEN MT902 AND MT903
[4] DISASSEMBLY/ASSEMBLY
[4]-1. Small spiral bevel gear, Armature, Ball bearings 6301ZZ and 6200ZZ
Code No. Description Use for
1R004 Retaining ring pliers ST-2 disassembling/ assembling Ring spring 15
disassembling/ assembling Retaining ring R-421R005 Retaining ring pliers RT-2N
1R027 Bearing setting pipe 18-10.2 disassembling Large spiral bevel gear from Spindle
1R269 Bearing extractor (small) removing Ball bearings
1R286
Model No. Small spiral bevel gear
(Gear on Armature shaft)
Large spiral bevel gear
(Gear on Spindle)
Round bar for Arbor disassembling large Spiral bevel gear from Spindle
Apply approx. 70g of Makita grease N No.1 to Gear room.
Refer to the following gears. They are not interchangeable.
DISASSEMBLING
MT902
MT903
Number of teeth: 16
Spiral bevel gear 16
Spiral bevel gear 12
Spiral bevel gear 53B
Spiral bevel gear 53A
Number of teeth: 12
28mm
22mm
grooved
not grooved
1. Remove Brush holder caps and
Carbon brushes from Motor
housing.
(1) Disassemble Gear housing complete and Bearing box. (Fig. 1)
2. Remove Gear housing complete together
with Armature from Motor housing by
unscrewing four 5x35 Tapping screws.
3. Remove Bearing box section
by unscrewing four 5x35
Hex socket head bolts.
Fig. 1
Brush holder caps
Carbon brushes Gear housing complete
Motor housing
Armature
Bearing box
section
5x35 Tapping screw (4pcs.)
5x35 Tapping
screw (4pcs.)

P 3/ 9
Repair
[4] DISASSEMBLY/ASSEMBLY
[4]-2. Small spiral bevel gear, Armature, Ball bearings 6301ZZ and 6200ZZ (cont.)
DISASSEMBLING
(2) Disassemble Armature and Small spiral bevel gear. (Fig. 2)
(3) Disassemble Ball bearings 6301ZZ and 6200ZZ. (Fig. 3)
Holding M8 Hex nut with Wrench 13,
turn Armature counterclockwise by hand.
M8 Hex nut can be removed.
Wrench 13 for holding
M8 Hex nut
M8 Hex nut
Pull off Armature while holding
Small spiral bevel gear.
Small spiral bevel gear
M8 Hex nut
Armature
Fig. 2
Note: If it is difficult to pull off Armature by hand, do the following steps.
1. Lubricate Small spiral bevel gear and Armature shaft with spray lubricant.
2. Wrap the gear with cloth to protect the gear teeth.
3. By
using water pump pliers, firmly grip the gear wrapped with cloth and then turn and pull Armature.
Retaining
ring R-42
Flat
washer 20
1. Remove Retaining ring R-42
with 1R005.
2. Remove flat washer 20.
3. Assemble Armature into Gear housing
complete then set Small spiral bevel gear
and M8 Hex nut in place on Armature
shaft temporarily.
1R005
Ball bearing
6301ZZ
Ball bearing 6301ZZ
M8 Hex nut
Small spiral
bevel gear
4. Tapping end of Gear housing
complete with Plastic hammer.
Ball bearing 6301ZZ can be
removed together with Armature.
5. Remove M8 Hex nut and Small spiral bevel gear again.
Ball bearing 6301ZZ can be removed by hand.
M8 Hex nut
1R269
Ball bearing 6301ZZ Ball bearing 6200ZZ
6. Remove Ball bearing 6200ZZ with 1R269.
Small spiral bevel gear
Fig. 3

P 4/ 9
Repair
[4] DISASSEMBLY/ASSEMBLY
[4]-2. Small spiral bevel gear, Armature, Ball bearings 6301ZZ and 6200ZZ (cont.)
ASSEMBLING
(1) Armature can be also used as an assembling jig for Ball bearing 6301ZZ. (Fig. 4)
(2) Assemble Spiral bevel gear 16 or 12 and M8 Hex nut to Armature shaft. Reverse step of disassembling. (Fig. 3)
Fig. 4
2. Set Ball bearing 6301ZZ to Armature temporarily and Assemble Ball bearing
6301ZZ into Gear housing complete by using with Armature as a jig,
and then pull off Armature from Ball bearing 6301ZZ.
1. Make sure that Rubber
ring 38 is set in Bearing
box of Gear housing
complete in advance.
Rubber ring 38
Ball bearing
6301ZZ
Ball bearing
6301ZZ
3. Put Flat washer 20 on Ball bearing 6301ZZ,
and secure them with Retaining ring R-42.
Retaining
ring R-42
Flat washer 20
1R005
Ball bearing
6301ZZ
Ball bearing 6301ZZ

P 5/ 9
Repair
[4] DISASSEMBLY/ASSEMBLY
[4]-3. Large spiral bevel gear, Ball bearing 6203DDW
DISASSEMBLING
(1) No need to separated Motor housing from Gear housing complete. Separate Bearing box section from Gear housing
complete, and remove Ball bearing and Ring spring from Spindle. (Fig. 5)
(2) Disassemble Spindle. (Fig. 6)
1. Remove bearing box section
by unscrewing four M6x22
Hex socket head bolts.
2. Remove Ball bearing 6000ZZ
with 1R269.
Fig. 5
Fig. 6
Bearing box
1R027
1R027
4. Strike 1R027 carefully with Ram until
Spindle is slightly shifted as illustrated
below.
5. Remove 1R027.
6. Set 1R286 onto Spindle,
and remove Spindle by
pressing down with Arbor
press.
Ram of Arbor press
1. Put Bearing box onto Turn base of Arbor
press with its Labyrinth ring side faced
to Turn base.
Note: Labyrinth ring must not touch
Turn base.
2. Insert 1R027 over Spindle.
3. Set Ram of Arbor press to 20 mm higher
position than the top of 1R027.
Bearing box
Turn base of
Arbor press
Spindle
3. Opening Ring spring 15 with 1R004,
lift the spring up from the opposite side
of 1R004 with Slotted screwdriver
and remove the spring from Spindle.
1R269
Ball bearing
6000ZZ
Ring spring 15
Slotted
screwdriver
1R004
Large spiral bevel
gear
1R286
Note: Do not reuse Ball bearing 6203DDW when Bearing box section
is disassembled. It is inevitably damaged.
20 mm
Labyrinth ring
Large spiral
bevel gear

P 6/ 9
Repair
[4] DISASSEMBLY/ASSEMBLY
[4]-3. Large spiral bevel gear, Ball bearing 6203DDW (cont.)
DISASSEMBLING
ASSEMBLING
(3) Disassemble Ball bearing 6203DDW. (Fig. 7)
(1) Put fresh Ball bearing 6203DDW into Bearing box and secure the Ball bearing with Bearing retainer 50 by
screwing M5x16 Pan head screws. (Fig. 7)
(2) Assemble Spindle by pressing with Arbor press through Ball bearing and Large spiral bevel gear. (Fig. 6)
(3) Assemble Ring spring 15 and Ball bearing 6000ZZ. (Fig.5)
1. Remove Large spiral bevel gear.
2. Remove bearing retainer 50 by unscrewing
three M5x16 Tapping screws.
Fig. 7
M5x16 Pan head
screws (3pcs.)
Bearing
retainer 50
Large spiral
bevel gear
3. Remove Ball bearing 6203DDW by striking Bearing box
against Worktable.
Note 1: Cover Worktable with something soft to avoid
the damage on Bearing box before disassembling.
Ball bearing
6203DDW
Note 2: Do not re-use Ball bearing 6203DDW, because it is
already damaged when removing Spindle.
(center of Fig. 6)

P 7/ 9
Repair
[4] DISASSEMBLY/ASSEMBLY
[4]-4. Shaft lock
DISASSEMBLYING
Fig. 8 Fig. 9
Setting 1R268 to Shoulder pin 5 through the small hole on Pin
cap, and tap 1R268 with Plastic hammer.
Shoulder pin 5 comes out from Gear housing complete.
Release 1R268 from Pin cap carefully
so that Pin cap does not be slung by
Compression spring 12.
Note: Do not reuse Pin cap, removal of
Shoulder pin 5 damages the inside
surface of Pin cap, producing plastic
dust.
Shoulder pin 5
(1) Remove Bearing box section from Gear housing complete. (Fig. 1)
(2) Shaft lock mechanism can be disassembled. (Figs. 8, 9)
1R268
Pin cap
Pin cap
Compression
spring 12
Fig. 10 Fig. 11
Pin cap
Compression spring 12
(1) Be sure to use a new Pin cap for replacement and to remove all the plastic dust on Shoulder pin 5. (Fig. 10)
(2) Assemble the Parts for Shaft lock mechanism. (Fig. 11)
Plastic dust
Shoulder pin 5
Remove Plastic dust from
the constricted part of
Shoulder pin 5.
Assemble Compression spring 12 and Pin
cap by pressing them to Shoulder pin 5.
Insert Shoulder pin 5 through the hole
of Gear housing complete.
ASSEMBLING
Shoulder
pin 5
Shoulder
pin 5

Circuit diagram
P 8/ 9
Power supply cord
Switch Field
Noise
suppressor
This Lead wire is blue for
some countries.
This Lead wire is brown for
some countries.
Color index of lead wires' sheath
Black
Fig. D-1
12
34
White
Noise suppressor is not used
for some countries.

Wiring diagram
Wiring in Handle set (L)
P 9/ 9
Wiring in Motor housing on the Commutator side
Pass Field lead wires
through hooks.
Hooks
To be connected
to Switch
Field lead wires (black)
Switch
Noise Suppressor
Power supply cord
Pass the Lead wires of Power
supply cord between Ribs.
Put Noise suppressor
here if it is used.
Fix Field lead wires
(2 x black) with Lead
wire holder.
Field lead wires
(black)
Rib
Handle Set (L)
Fig. D-2
Fig. D-3