Makita M1901B Operating instructions

M1901B
REPAIR MANUAL
Power Planer
OFFICIAL USE
For ASC

P 2 / 11
Repair
[1] NECESSARY REPAIRING TOOLS
Code No. Description Use for
1R045 Removing Spindle from Motor bracket
1R269 Removing Retaining ring S-7 from Spindle
GEAR EXTRACTOR (LARGE)
BEARING EXTRACTOR
[2] LUBRICATION
Item No. Description
Front base Screw hole accepting screw of Knob 44 a little
a littlesurface of Drum portion
Main frame complete
Amount
Symbol of
lubricant
Portion to lubricate
Apply lubricant VG100 to the parts designated with black triangle.
CAUTION: Repair the machine in accordance with “Instruction manual” or “Safety instructions”.
32
(32)
(a)
(b)
(a)
(b)
Knob 44
Screw portion
Flat washer 10
Rubber packing
Index
[1] NECESSARY REPAIRING TOOLS P 2
[2] LUBRICATION
[3] DISASSEMBLY/ASSEMBLY P 3
[3]-1. Poly V-belt 4-241
[3]-2. Armature P 4 - 5
[3]-3. Drum P 6 - 7
[3]-4. Front base, Base (rear side) P 8
[3]-5. Foot P 9
Circuit diagram P 10
Wiring diagram P 11

P 3 / 11
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -1. Poly V-belt 4-241
DISASSEMBLING
ASSEMBLING
(1) Disassemble Belt cover.
Remove Belt cover and then remove Poly V-belt 4-241 as illustrated in Fig. 2 in case of replacing the Poly V- belt only.
In case of replacing Armature, Ball bearings or Drum, remove the Poly V-belt as illustrated in Fig. 2A.
Cut Poly V-belt 4-241.
Fig. 2 Fig. 2A
Poly V-belt 4-241
Poly V-belt 4-241
Screwdriver
Bracket complete V Pulley 4-20L
1. Engage all V-shaped ribs of Poly V-belt 4-241
with the grooves of V-pulley 4-20L (small one).
And engage some of V-shaped ribs of the same
of the Poly V-belt with the groove of V-pulley
4-37 (large one).
2. Turn V-pulley 4-37 (large one), while pressing
the V-belt toward Bracket complete, until all
V-shaped ribs of Poly V-belt 4-241 with the grooves
of V-pulley 4-37 (large one). Now, Poly V-belt and
both of V-pulleys engage each other.
Poly V-belt 4-241
V-Pulley 4-20L
Poly V-belt 4-241 Poly V-belt 4-241
V-Pulley 4-20L
V-Pulley 4-37
Bracket complete
V-pulley 4-37
Poly V-belt 4-241
< Note >
Be careful,not to push so deep that
Poly V-belt 4-241 rubs against
Bracket complete.
Poly V-belt 4-241
V-pulley 4-37
(1) Mount Poly V-belt 4-241 as illustrated in Fig. 3.
Fig. 3
1. Insert screwdriver under Poly V-belt 4-241.
2. Lever up the Poly V-belt with the screwdriver,
while turning any of two V-pulleys.
Now, Poly V-belt 4-241 is removed.

P 4 / 11
Fig. 4
Fig. 5
Fig. 6
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -2. Armature
DISASSEMBLING
(1) In case of replacing Armature, remove Poly V-belt 4-241 as illustrated in Fig. 2A.
(2) Remove Carbon brush as shown in Fig. 4.
(3) For disassembling Armature, separate Bracket complete from Main frame, as illustrated in Fig. 5.
(4) Remove V pulley 4-20L by turning it clockwise as shown in Fig. 6 below.
1. Remove Nozzle by unscrewing M4x22 Pan head
screw.
2. Remove Brush holder cap and Carbon brush.
Nozzle
M4x22 Pan head screw
Carbon brush
Brush
holder cap
Brush holder cap
Bracket
Double ended philips bit
Bracket
4x18 Tapping screw
1. Unscrew six 4x18 Tapping screws
with which Bracket complete is
secured to Main frame. 2. Separate entirely Bracket complete, Armature and
Drum, by striking Main frame with plastic hammer.
Main frame
Armature
Main frame
Drum
Preset F/R Change lever
to F mode to turn the
V pulley 4-20L clockwise.
Grip Armature with groved
hand, to protect hand against
injury.
Turn clockwise
for removing.
12
3
6
9
V pulley 4-20L
Bit adapter
assembly
Bit adapter assembly
1/2” (12.7mm) asquare
Fit this side to the square
portion of V pulley 4-20L
Square portion of V pulley 4-20L

P 5 / 11
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -2. Armature
ASSEMBLING
DISASSEMBLING
(5) Separate Armature from Bracket complete, and remove Ball bearings as shown in Fig. 7.
Bracket complete
Bracket complete
Ball bearing
606ZZ
Ball bearing
606ZZ
Insulation washer
Insulation washer
1R045
Claw
Armature
Armature
Insulation
washer
1. Firmly gripping Bracket complete with 1R045, separate Armature from Bracket complete.
Drum
V pulley 4-20L
Fig. 7
Fig. 8
2. The gap between Insulation washer and
Ball bearing 606ZZ is too tight to engage
claw of 1R269. So, fixing claw of 1R269
with Water pump pliers firmly,
remove Ball bearing 606ZZ.
Ball bearing 606ZZ
Water pump pliers
1R269
Claw
Ball bearing 6000ZZ
Assembling can be made by taking reverse step of Disassembling. Refer to Fig. 7,Fig. 6,Fig. 5,Fig. 4.
3. Remove Ball bearing 6000ZZ with 1R269.
Turn counter
clockwise
for tightening.
12
3
6
9
V pulley 4-20L
Bracket complete
< Note >
Enough to tighten V pulley 4-20L
to proper level in this step.
V pulley 4-20L is tightened
automatically to firm level
by rotation of Armature.
Armature
Pay attention to Fig. 8, when assembling V pulley 4-20L.
Grip Drum with groved hand,
to protect hand against injury.

P 6 / 11
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -3. Drum
DISASSEMBLING
Fig. 9
Fig. 10
(1) Remove Poly V-belt 4-241. See Fig. 2A.
(2) Separate Bracket complete section from Main frame. See Fig. 4,Fig. 5.
(3) Separate Drum from Bracket complete as shown in Fig. 9.
Double ended Philips bit
Bit adapter assembly
1/2” (12.7mm) square
Fit this side to the square
portion of V pulley 4-37
Square portion of V pulley 4-37
Grip Drum with groved hand,
to protect hand against injury.
Turn counter clockwise
for removing.
1. Make the tip of claw shape, because
of too tight space between Ball
bearing 608ZZ and Drum to engage
the claws.
12
3
6
9
Bit adapter
assembly
V pulley 4-37
Preset F/R Change lever to
R mode to turn V pulley 4-37
counter clockwise.
Drum V pulley 4-37
Ball bearing 6000ZZ
Vise
Drum
Ball bearing 608ZZ
3. Remove Ball bearing 6000ZZ
with 1R269.
2. Fixing the legs of 1R269
with vise, disassemble Ball
bearing 608ZZ using the 1R269
with remodeled claws.
1R269
1R269
1R269
Ball bearing 608ZZ
Ball bearing 6000ZZ
(4) Disassemble Ball bearings from Drum as shown in Fig. 10.

P 7 / 11
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -3. Drum
ASSEMBLING
Fig. 11
< Note >
Mount V pulley 4-37 to Drum as follows. See Fig. 11.
(1) Assemble Ball bearing 608ZZ to Drum of opposite side of V pulley 4-37. And assemble Ball bearing 6000ZZ
to the same of V pulley 4-37 side. Refer to Fig. 10.
(2) Mount Drum to Bracket. And tighten V pulley 4-37 with Bit adapter. Refer to Fig. 9.
V pulley 4-37
Bracket complete
< Note >
Enough to tighten V pulley 4-37
to proper level in this step.
V pulley 4-37 is tightened
automatically to firm level
by rotation of Drum. Turn clockwise
for tightening.
12
3
6
9
Grip Drum with groved hand,
to protect hand against injury.
Bit adapter

P 8 / 11
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -4. Front base, Base (rear side)
DISASSEMBLING
Fig. 12
Fig. 13
(1) Front base section can be disassembled as shown in Fig. 12.
(2) Base (rear side) can be disassembled as shown in Fig. 13.
Base
Foot
1. Unscrew four 4x18 Tapping screws. So. Base (rear side) can be separated from Main frame complete.
2. Remove entirely Foot and Torsion spring 7.
Knob 44
Knob 44
Flat washer 10
1. Remove Knob 44 as shown below. 2. Front base can be separated
from Main frame complete.
3. Remove Scale label from
Knob 44, because the numbers
on Scale label deviates from the
actual planing depth, in case of
disassembling of Front base
and Base (rear side).
Front base Front base
Turn counter
clockwise for
unscrewing.
12
3
6
9
Compression
spring 18
Rubber packing
4x18 Tapping screw
4x18
Tapping screw
Torsion spring 7
4. From Front base, remove
Compression spring 18
and Rubber packing.
Scale label

P 9 / 11
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -4. Front base, Base (rear side)
[3] -5. Foot
ASSEMBLING, ADJUSTMENT
Fig. 14
Fig. 15
(1) Mount Foot to Base. And assemble the Base to Main frame complete. Refer to Fig. 13.
(2) Mounting Rubber packing and Compression spring 18 to Front base, assemble the Front base
to Main frame complete. Refer to Fig. 12.
(3) Adjust with Knob 44, until “0” on the Scale label correspond to the actual planing depth “0” as shown in Fig. 14.
Ruler
Front base
Knob 44
Base (rear side)
1. Apply a ruler on the surface of Base
and align Front base level by turning
Knob 44 to the same level of (rear) Base.
Now, the machine has been adjusted
to “Planning depth at 0”.
2. Stick Scale label on the Knob 44,
while aligning “0” to the Triangle
mark on the main fame.
Triangle mark
fresh Scale label
2a. If the removed Knob 44 is reused without sticking new Scale label, “0” may deviate from the
Triangle mark by 180 degrees.
Remove knob 44 again in this case, and approach to drive from the point deviating by 180 degrees
from the old approaching point. So, “0” can exactly align to the Triangle mark.
DISASSEMBLING
ASSEMBLING
Disassemble Base (rear side). So, Foot is removed together with Base as shown in Fig. 13.
Assemble Foot to Base as shown in Fig. 15.
Tail of Torsion
spring 7
long axis
short axis
Torsion spring 7
Torsion spring 7
1. Set Torsion spring 7 to long axis of Foot. 2. Put one of tail of Torsion spring 7
to Base as shown in the photograph
below.
Foot

P 10 / 11
Fig. D-1
Circuit diagram
White
Brown
Color index of lead wires' sheath
Black
Blue
< Note >
AWG: American Wire Gage
Item No.
(2)
(2)
(1)
(1)
Circuit of inside of Switch
Symbol of electrical parts
< Note >
Noise suppressor is not used for some countries.
Viewing from Fan side
AWG18
AWG18
Noise suppressor
Power supply cord
Field
AWG18
AWG18
Insulated terminal (M3.5)
Non-Insulated Spring terminal
AWG20
(2)
(1)
Switch

P 11 / 11
Fig. D-2
Wiring diagram
Keep so enough distance from Insulated terminal
of Switch, that Noise suppressor does not interferes
with setting of Switch, when Noise suppressor is used.
Noise suppressor
Switch
Insulated terminals
Field
Pass Field lead wires
through this hole to handle
section, and connect them
to Switch.