Hitachi G 10SF3 Manual

POWER TOOLS
TECHNICAL DATA
AND
SERVICE MANUAL
DISC GRINDER
G 10SF3
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No. E243 Aug. 2001
G
MODEL
G 10SF3

REMARK:
Throughout this TECHNICAL DATA AND SERVICE MANUAL, a symbol(s)
is(are) used in the place of company name(s) and model name(s) of our
competitor(s). The symbol(s) utilized here is(are) as follows:
Symbols Utilized
Competitors
Company Name Model Name
MAKITA 9523NB
C

Page
CONTENTS
1. PRODUCT NAME ...........................................................................................................................1
2. MARKETING OBJECTIVE .............................................................................................................1
3. APPLICATIONS ..............................................................................................................................1
4. SELLING POINTS ..........................................................................................................................1
5. SPECIFICATIONS ..........................................................................................................................3
6. COMPARISONS WITH SIMILAR PRODUCTS ..............................................................................4
6-1. Specification Comparisons ............................................................................................................ 4
6-2. Comparisons in Torque vs. Rotation Speed and Stator Coil Temperature Rise ............................ 5
7. PRECAUTIONS IN SALES PROMOTION .....................................................................................6
7-1. Handling Instructions ..................................................................................................................... 6
7-2. Caution Plate (For China only) ...................................................................................................... 6
7-3. Precautions on Usage ................................................................................................................... 6
8. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY ............................................................7
8-1. Disassembly .................................................................................................................................. 7
8-2. Reassembly ................................................................................................................................... 9
8-3. Lubrication Points and Types of Lubricant .................................................................................... 11
8-4. Tightening Torque ......................................................................................................................... 11
8-5. Wiring Diagram ............................................................................................................................. 11
8-6. Insulation Tests ............................................................................................................................ 12
8-7. No-load Current Value ................................................................................................................. 12
9. STANDARD REPAIR TIME (UNIT) SCHEDULES .......................................................................13
Assembly Diagram for G 10SF3

--- 1 ---
1. PRODUCT NAME
Hitachi Disc Grinder, Model G 10SF3 [100 mm (4")]
2. MARKETING OBJECTIVE
The current Model G 10SF2 has been favorably accepted in the compact disc grinder market in China. However,
recent Chinese market is fiercely competitive due to a price war. To address the severe situation, we have
developed a new disc grinder Model G 10SF3 that is comprised of parts manufactured in China. The Model
G 10SF3 is more powerful than the current Model G 10SF2 thanks to the improved cooling efficiency of the motor.
The components of the Model G 10SF3 are the same as those of the Model G 10SF2 except the enclosure and
the wiring components.
3. APPLICATIONS
Removal of casting fin and finishing of various types of steel, bronze, aluminum, and other metallic materials
and castings
Grinding of welded sections, or sections cut by acetylene torch
Grinding of slate, brick, marble and similar materials
4. SELLING POINTS
High power input: 560 W
(G 10SF2 and C: 540 W)
New vaned dust seal efficiently
prevents dust from entering the ball
bearing on the commutator side.
Easy-to-use snap switch
Excellent wear resistance of armature coil:
2 times higher than the Model G 10SF2
1.7 times higher than C

--- 2 ---
Excellent wear resistance of armature coil
Wear resistance of the armature coil is greatly increased thanks to the smaller air vent to minimize sucking
dust and fine gravel into the machine.
G 10SF3
(Comparison of wear resistance of armature coils when dust and fine gravel are sucked into the machines)
(Comparison of air vents near the commutator)
Smaller air vent is
provided near the
commutator. Two air vents are provided
near the commutator.
G 10SF2
100
40
100
G10SF3
G10SF2
50
C
10 13.5
0
60

--- 3 ---
Depressed
center
wheel
5. SPECIFICATIONS
4,300 m/min (14,100 ft/min, 72 m/s)
Dimensions
Model
Item
O.D. 100 mm (4") x Thickness 4 mm (5/32")
x I.D. 16 mm (5/8")
Offset amount: 4 mm (5/32")
Max. peripheral speed
G 10SF3
AC single phase 50 or 60 Hz
Power source
Snap switch
1.4 kg (3.09 lbs.)
2.4 kg (5.3 lbs.)
Corrugated cardboard box
No-load speed
Type of motor
Enclosure
Type of switch
Weight Net: *1
Gross:
Packaging
Standard accessories*2Depressed center wheel [Outer dia.100 mm (4") ] .................1
Wrench ...................................................................................1
Voltage, current and power input
12,000/min
AC single phase commutator motor
Housing tail cover
Gear cover
Inner cover packing gland
Glassfiber reinforced polycarbonate resin (Green)
Aluminum alloy die casting (Metallic silver)
Aluminum alloy die casting
Voltage (V)
Current (A)
Power input (W)
220
560
2.7
*1: Net weight excludes cord, depressed center wheel, wheel nut, wheel washer and wheel guard.
*2: Standard accessories are subject to change without prior notice.

--- 4 ---
HITACHI
G 10SF3
100
12,000
560
380
640
254
67
60
200
1.4
(1.5)
Snap
Maker
Model
Wheel diameter mm
No-load speed /min
Power input W
Power output W
Max. power output W
L mm
Dimensions W mm
H mm
P mm
Weight * kg
(Actual weight)
Type of switch
6. COMPARISONS WITH SIMILAR PRODUCTS
6-1. Specification Comparisons
G 10SF2
100
12,000
540
330
610
254
67
60
200
1.4
(1.5)
Snap
100
11,000
540
290
620
256
81
70
195
1.4
(1.5)
Slide
C
L
H
W
P: Perimeter
* Weight excludes cord, depressed center wheel, wheel nut, wheel washer and wheel guard.

--- 5 ---
6-2. Comparisons in Torque vs. Rotation Speed and Stator Coil Temperature Rise
Figure 1 shows comparisons of the rotation speed and the stator coil temperature rise between a competitive
model with respect to torque. Torque represents the magnitude of load, i.e., the amount of pressing force, cutting
depth and forward force in actual cutting jobs. This shows that a powerful motor is less likely to burn out because
it has both a minimum drop of rotation speed even at a greater torque and a lower stator coil temperature rise at
the same torque.
Fig. 1 Comparisons in torque vs. rotation speed and stator coil temperature rise
Figure 1 indicates the followings:
The motor speed of the Model G 10SF3 is higher than that of C at the same torque. This means that the
working efficiency of the Model G 10SF3 is superior to C (Model G 10SF2 is also superior to C).
The stator coil temperature rise of the Model G 10SF3 is lower than the Model G 10SF2 thanks to the
improved cooling mechanism and it is equivalent to that of C. This means that the Model G 10SF3 has a burn-
resistant and tenacious motor.
Load
Stator coil temp. rise (K)
2,000
0
C
4,000
6,000
8,000
12,000
10,000
0
0
600
100
200
300
400
500
Rotation speed of spindle (/min.)
X
X
X
C
Torque range
HITACHI G 10SF3
Stator coil temp. rise
X: Burn-out point
HITACHI G10SF2
HITACHI G 10SF2, G 10SF3
Rotation speed of spindle

--- 6 ---
7. PRECAUTIONS IN SALES PROMOTION
In the interest of promoting the safest and most efficient use of the Model G 10SF3 Disc Grinder by all of our
customers, it is very important that at the time of sale, the salesperson carefully ensures that the buyer seriously
recognizes the importance of the contents of the Handling Instructions, and fully understands the meaning of the
precautions listed on the Name Plate attached to each tool.
7-1. Handling Instructions
Although every effort is made in each step of design, manufacture and inspection to provide protection against
any hazards, the dangers inherent in the use of any electric tool cannot be completely eliminated. Accordingly,
general precautions and suggestions for the use of electric power tools, and specific precautions and suggestions
for the use of the disc grinders are listed in the Handling Instructions to enhance the safe, efficient use of the tool
by the customer. Salespersons must be thoroughly familiar with the contents of the Handling Instructions to be
able to offer appropriate guidance to the customer during sales promotion.
7-2. Caution Plate (For China only)
The following caution is listed on the Name Plate attached to the main body of each tool.
7-3. Precautions on Usage
Instruct the customer to pay particular attention to the two points described below.
(1) Use of the side handle (Optional accessory)
When the side handle is used, the customer must be instructed to ensure without fail that the wheel guard is
mounted in the manner so that it protects the operator's hand from coming into contact with the depressed
center wheel.
Fig.2
Side handle
Pushing button
Wheel guard
(2) Never press the pushing button while the depressed center wheel is rotating.
If the pushing button (Fig. 2) is pressed while the depressed center wheel is rotating, the spindle will stop
immediately. In such a case, there is a danger that the wheel nut may be loosened, so that the depressed
center wheel flies out unexpectedly and may cause possibly serious injury.

--- 7 ---
8. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY
Procedures and precautions for disassembly and reassembly are described below. The [Bold] numbers in the
descriptions below correspond to the item numbers in the Parts List and the exploded assembly diagram.
8-1. Disassembly
(1) Disassembly of the armature
Remove the Brush Caps [39], and take out the Carbon Brushes [40].
Loosen the four Tapping Screws D5 x 25 [1] which fix the Gear Cover Ass'y [3], and remove the Inner
Cover [8] together with the Armature 220 V [9] from the Housing [34].
(2) Disassembly of the pinion
Loosen the Special Nut M7 [4] on the Armature 220 V [9], and remove the Pinion [5].
(3) Disassembly of the stator
Remove the Armature 220 V [9] and loosen the Tapping Screw (W/Flange) D4 x 25 (Black) [48] to remove
Tail Cover (B) [47].
Loosen the Machine Screw (W/Washer) M3.5 x 6 [49] that secures the internal wire of the Cord [51] to the
Switch [50] and also the screw on the cord side of the Pillar Terminal [43]. Remove the two internal wires
from the Cord [51].
Remove the Tapping Screw (W/Flange) D4 x 40 [38] and the Tapping Screw (W/Flange) D4 x 20 (Black)
[37]. Remove Tail Cover (A) [36] then remove the Earth Terminal [44] from the Housing [34].
Disconnect the two Internal Wires [13] coming from the Brush Holder [41] from the Stator [11].
Remove the Internal Wires [12] and [14] from the Stator [11] with the Pillar Terminal [43], Noise Suppressor
[46] and Switch [50] connected.
Loosen the Hex. Hd. Tapping Screw D4 x 65 [10] securing the Stator [11]. Remove the Stator [11] from the
Housing [34].