Makita BFT042F Manual

Models No.
Description
PRODUCT
CONCEPTION AND MAIN APPLICATIONS
Specification
Standard equipment
Optional accessories
P 1/13
TECHNICAL INFORMATION
BFT042F
Cordless Screwdriver 12V
Model BFT042F has been developed as a sister model of BFT040F,
featuring rotational speed higher than the current model:
BFT042F/1,200 min-1, BFT040F/950 min-1
Battery BH1220C
Battery BH1233C
Fast charger DC18RA
Charger DC24SA (for North America only)
Charger DC24SC (for all countries except North America)
Auto refresh adapter ADP03
Protectors (red/ blue/ yellow/ clear)
Torque adjust tool
Grip base (for Grip 37)
Grip 37 (Side grip)
242 (9-1/2)
251 (9-7/8)
with BH1220C
with BH1233C
Dimensions: mm (")
Width (W)
Height (H)
Length (L) 200 (7-7/8)
71 (2-13/16)
L
H
W
BFT042F
Model
Specifications
No load speed: rpm= min-1 1,200
15/ 22
with DC18RA
150
1.5*1/ 1.7*2
(3.3*1/ 3.7*2)
Battery
Driving shank: mm (")
Net weight: kg (lbs)
LED Job light
Torque adjustment
Torque range:
N.m (in.lbs)
1 - 4 (8.9 - 35)
1 - 3.5 (8.9 - 30)
Hard joint
Soft joint
Yes
Yes
Hex 6.35 (1/4)
Electric brake
Soft start Yes
Reverse switch Yes
Yes
Cell
Charging time: min.
Voltage: V
Capacity: Ah
Ni-MH
12
2.0/ 3.3
Max output: W
*1 with 2.0Ah battery BH1220C, *2 with 3.3Ah battery BH1233C
No, but the following item(s) will be supplied with the machine if required:
Torque adjust tool
Protector

P 2/13
[1] NECESSARY REPAIRING TOOLS
CAUTION: Remove the battery from the machine for safety before repair/ maintenance,
in accordance with the instruction manual!
Repair
1R004 Retaining ring S pliers ST-2 Removing/installing Ring spring 11
1R035
1R036
Bearing setting plate 15.2 Installing Ball bearing 6801LLB and Ring 12
Removing Ball bearing 6801LLB and Ring 12 from Spindle
Removing Steel balls
Removing Retaining R-21
Assembling Spindle section to Clutch case
Assembling Spindle section to Clutch case
Bearing setting plate 17.2
1R237 Round bar for arbor 8-100
1R269 Bearing extractor
1R288 Screwdriver magnetizer
1R291 Retaining ring S and R pliers
Removing/installing Ring spring 10 from/on Spindle M
Assembling Torx countersunk head screw M5x10 to Spindle
Removing Torx countersunk head screw M5x10 from Spindle
1R145 L type Torx wrench set
1R219 Torx wrench shaft 7-23N.m
1R220 Ratchet head 9.5 (1R219)
1R222 Socket adapter (1R219)
765027-4 Torque adjust tool
Disassembling *Clutch section
1R314 Torx bit VT-25
Assembling Torx countersunk head screw M5x10 to Spindle
1R311 Retaining ring pliers with long bent nails
Code No. Description Use for
*Note: Clutch section is described as "Clutch assembly D" in the Parts list.
[2] LUBRICATION and ADHESIVE APPLICATION
Apply the following lubricants to protect parts and product from unusual abrasion (Fig. 1):
Sealing lubricant No.101 to the portions designated with the gray triangle
Makita grease N. No.2 to the portions designated with the black triangle
Apply ThreeBond 1303 or Loctite 603 to the portions designated with the black arrow. (Fig. 1)
LUBRICATION
Fig. 1
Item No. Description Lubricant Portion to lubricate
ADHESIVE APPLICATION
Item No. Description Portion to apply adhesive
Torx countersunk head screw M5x10
Inner threaded portion for Torx countersunk head screw M5x10
: Makita grease N. No.2
: ThreeBond 1303 or Loctite 603
: Sealing lubricant No.101
Makita grease
N. No.2
Sealing lubricant
No.101
Flat washer 7
Compression spring 19D
Cam D
35
34
38
40
Ball bearing
6805LLB
Gear case
Lock washer
Motor bracket
44
50
47
48
49
Spindle Threaded portion for engaging with Lock nut M12
Whole surface
Whole surface
Whole surface
Steel ball 5.0 (3 pcs)
Steel ball 4 (3 pcs)
Steel ball 3 (13 pcs)
35
34
Spindle
34
38
40
Cam C
Carrier complete A
Spur gear 13 (3 pcs)
Spur gear 20 complete C
Spur gear 15 (3 pcs)
Internal gear 47
44
50
47
48
49
Teeth portion
Teeth portion
Teeth portion that engages with and
Teeth portion and three shaft pins for
Three shaft pins for 47
47 49
49

P 3/13
[3] DISASSEMBLY/ASSEMBLY
[3] -1. Bit Holder Section
Repair
Bit holder section can be disassembled from Spindle M
as illustrated in Fig. 2 by removing Ring spring 10
from the groove of Spindle M using 1R291 or the like.
1) Disassemble Bit holder section from Spindle M. (Refer to [3] -1. Bit Holder Section.)
2) Remove Ring 38G from Clutch case by unscrewing (+) Pan head screw M4x4 (silver), then remove Clutch case cover
from Clutch case by unscrewing Pan head screw M4x8 (black).
Switch lever and Compression spring 2 can now be removed. (Fig. 3)
3) Remove Clutch case from Housing by unscrewing four M4x22 (+) Pan head screws.
Clutch section (= Clutch assembly D) can now be removed from Housing. (Fig. 4)
Note: Be careful not to lose Compression spring 5 located in Clutch section. (Fig. 5)
4) Remove Retaining ring R-21 that holds Spindle section in place on Clutch case using 1R311. (Fig. 6)
5) Remove Spindle section from Clutch case by tapping the end surface of Clutch case with plastic hammer. (Fig. 7)
Fig. 5 Fig. 6 Fig. 7
[3] -2. Spindle Section
Clutch case
Compression spring 5
Clutch section
Spindle section
Fig. 3
(+) Pan head screw
M4x4 (silver)
Ring 38G
Clutch case cover
Clutch case
DISASSEMBLING
DISASSEMBLING
Steel ball 3 (2 pcs)
Compression spring 13
Flat washer 11
Spindle M
Sleeve
Ring spring 10
Fig. 2
groove
Pan head screw M4x8 (black)
Switch lever
Compression spring 2
Fig. 4
(+) Pan head screw M4x22 (4 pcs)
Clutch case
Clutch section
(= Clutch assembly D)
Housing
Retaining ring R-21
1R311
Clutch case
Switch unit

P 4/13
[3] DISASSEMBLY/ASSEMBLY
[3] -2. Spindle Section
Repair
Ring 12
Ball bearing
6801LLB
1R269
Ring spring 11
1R004
Fig. 8 Fig. 9
Ring 12
Ball bearing
6801LLB
Spindle M
Fig. 10
Fig. 12
6) Remove Ring spring 11 using 1R004. (Fig. 8)
7) Remove Ball bearing 6801LLB using 1R269. (Fig. 9)
8) Remove the other Ball bearing 6801LLB together with Ring 12 using 1R269. (Fig. 10)
1) Assemble Spindle section using 1R035, arbor press and 1R004. (Figs. 11, 12)
Note: Ring spring 11 is deformed in the disassembling step.
Be sure to use new Ring spring 11 when assembling Spindle section. (Fig. 12)
2) Assemble Spindle section to Clutch case using 1R237, 1R036, arbor press and 1R311. (Fig. 13, 14)
Ball bearing
6801LLB
Fig. 11
1R035
Spindle M
Ball bearing
6801LLB
Fig. 14
1R311
Retaining ring R-21
Fit Retaining ring 21 exactly
in this inner groove to hold
Spindle section securely.
Fig. 13
1R237
Clutch case
Spindle section
DISASSEMBLING
ASSEMBLING
1R269
arbor press
Ring spring 11
1R004
Note:
Be sure to use
new one.
arbor press
1R036

P 5/13
[3] DISASSEMBLY/ASSEMBLY
[3] -2. Spindle Section (cont.)
Repair
2) Make sure that Compression spring 5 is located in place in Clutch section before assembling Clutch section and
Clutch case to Housing. (Fig. 5 on page 3)
3) Assemble Clutch section and Clutch case to Housing by screwing four M4x22 (+) Pan head screws. (Fig. 4 on page 3)
Then put the Lead wires of Switch unit and LED Job light in place as illustrated in Fig. D-3 on page 13.
4) Put Switch lever and Compression spring 2 in the space between Switch unit and Clutch case. (Fig. 3 on page 3)
5) Secure Clutch case cover to Clutch case with Pan head screw M4x8 (black). Then secure Ring 38G to Clutch case
with (+) Pan head screw M4x4 (silver). (Fig. 3 on page 3)
[3] -3. Clutch Section
1) Take out Clutch section. (Figs. 3, 4 on page 3)
Note: Be careful not to lose Compression spring 5. (Fig.5on page 3)
2) Insert 765027-4 into the hole of Adjust ring complete, and turn it counterclockwise to reduce the tension of
Compression spring 19D.
Lock nut M12 (left-hand threaded) can now be removed by turning it in the direction of the black arrow by hand.
(Fig. 15)
3) Remove Adjust ring complete, Flat washer 18 and Compression spring 19D from Spindle. (Fig. 16)
4) The following Steel balls can be removed as illustrated in Fig. 17:
Steel ball 3 (13 pcs), Steel ball 4 (3 pcs), Steel ball 5.0 (3 pcs)
Note: Use a screwdriver magnetized with 1R288 for easy removal of Steel balls.
It is recommended to wholly replace Clutch section (= Clutch assembly D) when it is broken.
However, if you need to replace some component part(s) of Clutch section independently, disassemble/assemble
Clutch section as described below.
Fig. 17
Flat washer 18
Compression
spring 19D
Compression
spring 19D
Adjust ring complete
Fig. 16
Cam D
Steel ball 4
(3 pcs)
Steel ball 5.0
(3 pcs)
Cam C Steel ball 3.0
(13 pcs)
Cam C
Fig. 15
Lock nut M12
Adjust ring complete
Clutch section
(=Clutch assembly D)
ASSEMBLING
DISASSEMBLING
765027-4
Lock nut M12
Spindle
Steel ball 4 (3 pcs) and Steel ball 5.0 (3 pcs)
can be removed by moving Cam D towards
the threaded end of Spindle.
After removing Steel ball 4 (3 pcs) and Steel ball 5.0 (3 pcs),
Steel ball 3 (13 pcs) can be removed by moving Cam C
towards Cam D.
Cam D

P 6/13
[3] DISASSEMBLY/ASSEMBLY
[3] -3. Clutch Section (cont.)
Repair
Fig. 18
Fig. 19
DISASSEMBLING
5) Insert short leg of hex wrench 6 into the hole of Spindle, and fix long leg of the hex wrench securely in vise.
Insert No.T25 Torx wrench of L type Torx wrench set (1R145) into the socket of Torx countersunk head screw M5x10.
Then remove the screw by turning No.T25 Torx wrench counterclockwise as illustrated to left in Fig. 18.
The following parts can now be removed from Spindle: Cam D, Cam C, Flat washer 7. (right in Fig. 18)
Torx countersunk head
screw M5x10
Hex wrench 6
No.T25 Torx wrench
6mm
Spindle
Flat washer 7Cam CCam D
Spindle Torx countersunk head
screw M5x10
Do the reverse of the disassembling steps.
Note:
When fastening Torx countersunk screw M5x10 to Spindle, do as described in Fig. 19.
Apply Sealing lubricant No.101 to all Steel balls and the Spindle's threaded portion for engaging with Lock nut M12
before assembling. (Fig. 1 on page 2) Be careful not to put the grease in the threaded hole of Spindle.
ASSEMBLING
Spindle
Torx countersunk head
screw M5x10
Clean up this threaded portion
with gasoline or kerosene to
remove oil or grease. 1R219
1R220
1R222
1R314
Fix Spindle in vise.
Then fasten Torx countersunk head screw M5x10
to the recommended torque of 8-10N.m by turning
clockwise using 1R219, 1R220, 1R222 and 1R314.
Note: Wipe away any adhesive that might ooze out.
Clean up this threaded hole
with gasoline or kerosene
to remove oil or grease from
the inner threaded portion.
Put about three drops of
ThreeBond 1303 or Loctite 603
in this threaded hole.

P 7/13
[3] DISASSEMBLY/ASSEMBLY
[3] -4. Motor and Gear Section
Repair
1) Remove Bit holder section, Switch lever, Clutch case and Clutch section (=Clutch assembly D) from Housing.
(Figs. 2, 3, 4 on page 3)
2) After removing Brush holder cap and Carbon brush, remove Housing (L) from Housing (R) by unscrewing
eight M3x20 Pan head screws. Then remove Switch unit from Gear section. (Fig. 20)
3) Disconnect Lead wires of Endbell complete from Switch, then lift up and remove the assembly of Gear section and
Motor section from Housing (R). Pull off Gear section from Motor section while turning Motor bracket in the direction
of the arrow. (Fig. 21)
Fig. 20
Gear section
Lead wire
of Endbell complete
Motor section
DISASSEMBLING
Plate
Motor bracket
Lens
Housing (R)
Brush holder cap
Carbon brush
Pan head screw
M3x20 (8 pcs)
Housing (L)
Gear section
Switch unit
Fig. 21
Switch

P 8/13
[3] DISASSEMBLY/ASSEMBLY
[3] -4. Motor and Gear Section (cont.)
Repair
1) Apply Makita grease N No.2 to teeth portions of all Gears and all Shaft pins portion of the Carrier complete A and
Spur gear 20 complete. (Fig. 1 on page 2)
2) Assemble Gear section as illustrated in Figs. 24, 25.
Fig. 25
Motor bracket
Lock Motor bracket in place
by turning clockwise.
ASSEMBLING
Carrier complete A
Ball bearing
6805LLB
Internal gear 47
Gear case
Shaft pins for
Spur gear 13
Spur gear 13
(3 pcs)
Spur gear 20
complete C
Spur gear 15
(3 pcs)
Fig. 24
Shaft pins for
Spur gear 15
Gear case
pliers
Lock washer
Endbell complete
Armature
Yoke unit
Fig. 23
Gear case
Lock washer
4) Remove Endbell complete from Armature, then pull Armature from Yoke unit. (Fig. 22)
5) Remove Lock washer by turning it with pliers. Gear section can now be disassembled as illustrated in Fig. 23.
Fig. 22
Disassembling Motor Section Disassembling Gear Section
Note:
Be careful not to pinch your fingers between
Armature and Yoke unit when removing/
installing Armature because Yoke unit is
a strongly magnetic body and pulls Armature
strongly.
Ball bearing
6805LLB
Spur gear 20 complete C
Spur gear 13
(3 pcs)
Carrier complete A Gear case Internal gear 47 Spur gear 15
(3 pcs)
DISASSEMBLING

P 9/13
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -4. Motor and Gear Section (cont.)
3) Assemble Motor section. (Fig. 22 on page 8)
Assemble Motor section and Gear section together while
turning Motor bracket in the direction of the arrow.
Then install Switch unit on Gear case, and connect Lead
wires of Endbell complete to Switch. (Fig. 26)
4) Put the assembly of Gear section and Motor section
in place on Housing (R), then fasten Housing (L) to
Housing (R) as illustrated to left in Fig. 22 on page 7.
Note:
Do not forget to install Plate and Lens on Housing (R).
See Figs. D-2, D-3 on pages 12, 13 for detailed
information on wiring.
ASSEMBLING
Gear section
Switch unit
ribs to hold
Switch unit
Note:
Ribs to hold Switch unit must face
the top side of the machine.
Fig. 26
Motor bracket
Housing (R)
Motor section
Lead wire
of Endbell complete

P 10/13
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -5. Switch Section
[3] -6. Replacing Switch Unit, LED Circuit, Buzzer Circuit
After removing F/R change lever, unscrew the screw that fastens
Micro switch to Reverse switch.
Micro switch can now be removed by pulling in the direction of
the gray arrow while turning it counterclockwise. (Fig. 27)
DISASSEMBLING
1) Assemble Micro switch to Reverse switch by fastening
the screw to the recommended torque of 0.29 - 0.34N.m.
2) Fitting the boss of Reverse switch in the concave portion of
F/R change lever, assemble F/R change lever to Reverse switch.
(Fig. 28)
3) Assemble Trigger switch section to Housing (R).
When removing LED circuit, Switch unit and Buzzer circuit,
disconnect Connectors by pulling them in the direction designated
with the arrow. (Fig. 29)
Note: To protect Lead wires from breaking, do not hold
Lead wires when pulling Connectors.
Refer to "Circuit Diagram" on page 11
when connecting Connectors.
Fig. 27
screw
Micro switch
Reverse switch
F/R change lever
ASSEMBLING
DISASSEMBLING
ASSEMBLING
concave portion
of F/R change lever boss of Reverse switch
Fig. 28
Controller
LED circuit
Buzzer circuit
Switch unit
Connector Connector
Connector
Fig. 29

Circuit diagram
P 11/13
Color index of lead wires' sheath
Black
White
Red
Orange
Blue
Yellow
Purple
Gray
Fig. D-1
LED
circuit
Switch
unit
Buzzer
circuit
DC Motor
(Endbell)
Terminal
Controller
Indicator lamp
is built in this
Controller.
COM NO
Micro Switch
Reverse
switch
M2
S1
S2
M2
M1
Switch section
Connector
Connector
Protective tube
(heat-shrink tube)
Connector

Wiring diagram
P 12/13
1) Wiring in Housing (R)
Fig. D-2
[Routing Lead wires (black, red) of Endbell complete]
Black wire: Route beside the right side of the LED cover
portion of Controller, then connect to No. M2
terminal of Switch section.
Red wire: Route beside the left side of the LED cover
portion of Controller, connect to No. M1
terminal of Switch section. LED cover portion
Lead wire (black)
Endbell complete
Route the following seven Lead wires
of Controller between the ribs of
Switch section:
two wires (white, orange)
to Micro switch of Switch section
three wires (blue, purple, white)
to Reverse switch of Switch section
two wires (red, white)
to Buzzer circuit
Note:
Be careful not to pinch these
Lead wires between Switch section
and the inside wall of Housing.
Connector
LED circuit
Controller
Switch unit*
rib
Note: See next page for wiring of Switch unit and Switch section.
Terminal
Be sure to place Sponge
of Buzzer circuit on
Housing (L) side.
Buzzer
circuit
rib
Put the Connectors
in the space between
this line and Terminal.
Route the following four
Lead wires between the rib
and the inside wall of
Housing:
Lead wires (black, red)
of Terminal
Lead wires (white, red)
of Buzzer circuit
Place the following parts outside of Housing (R):
Connectors and Lead wires (purple, yellow)
that connect Controller with Switch unit
Connectors and Lead wires (gray, blue)
that connect Controller with LED circuit
Lead wire (red)
Switch section*
Controller

LED circuit
Controller
Switch section
Wiring diagram
P 13/13
Fig. D-3
3) Wiring on the Outside of Housing
Wiring of Lead wires (yellow, purple) that connect Switch unit with Controller
(These Lead wires are covered with a protective tube, and designated by "Wire yp" in the illustrations below.)
Wiring on the shelf portion of Housing
Wiring on Switch section
Route Wire yp:
under pin A of Housing (L),
through the groove on Clutch case,
inside pin B of Housing (L),
between the raised portion and flanged portion of
Clutch case,
inside pin C of Housing (L),
through Lead wire holder of Housing (L).
3
1
2
6
4
5
Put the following Connectors and slack portion of
Lead wires on the shelf portion of Housing:
Connectors and Lead wires (including "Wire yp")
that connect Controller with Switch unit
Connectors and Lead wires that connect Controller
with LED circuit
Note:
Be sure to put the Connectors and the slack portion
in place carefully so that they are not pinched
between Housing and Clutch case cover.
Assemble the receptacle on
each Lead wire to the terminal of
Switch section as illustrated below.
Switch unit
pin A of Housing (L)
Wire yp 1
pin B of
Housing (L)
flanged portion
of Clutch case
raised portion
Lead wire holder
Wire yp
3
2
6
4
5pin C of
Housing (L)
Switch unit
shelf portion
of Housing
LED circuit
Wire yp
from Controller
(white)
from Controller
(purple)
from Controller
(orange)
Micro switch
[Reverse switch side] [Micro switch side]
Reverse
switch side
Micro
switch side
Switch unit
Wire yp
Note: "Wire yp" must be tight between Switch unit
and Lead wire holder of Housing (L).
from Controller (blue)
from Endbell complete
(black)
from Controller (white)
from Endbell complete
(red)
Fix the Lead wires with these Lead wire holders.
receptacle