Makita GA5020C User manual

PRODUCT
P 1/10
TECHNICAL INFORMATION
Model No.
Description
CONCEPT AND MAIN APPLICATIONS
Specification
Standard equipment
Note: The standard equipment for the tool shown above may differ from country to country.
GA5020C/GA6020C, GA5021C/GA6021C
Angle Grinders 125mm (5") /150mm (6")
These four models have been developed as the most advanced models of
our GA5010 series, featuring a variety of value-adding functions as follows:
*Electronic control including;
Constant speed control, Soft start, Electronic current limiter,
Anti-restart function, LED power light
*Super Joint System (SJS)
GA5020C/GA6020C use Single-finger trigger while GA5021C/GA6021C
use Large type trigger.
Lock nut wrench 35 .............. 1
Lock nut wrench 28 .............. 1
Depressed center wheel ......... 1 (125-36 for GA5020C and GA5021C, 150-36 for GA6020 and GA6021C)
Side grip (soft grip) ............... 1
Toolless wheel cover ............. 1 (if required)
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)
GA5020C GA6020C GA5021C GA6021C
125 (5) 150 (6)
Australia: 2.0 (6.6), Other countries: 2.5 (8.2)
2.5 (5.5)
10,000 9,000
125 (5) 150 (6)
10,000 9,000
Double insulation
22.23 (7/8)
Super Joint System (SJS) Yes
Constant speed control Yes
LED power light Yes
Soft start Yes
Electronic current limiter Yes
Anti-restart function Yes
120
110 14 1,450
---
1,000 2,20050/60
6.9 1,450 1,000 2,60050/60
6.6 1,450 1,000 2,60050/60
6.4 1,450 1,000 2,60050/60
12.5 1,000 2,20050/60
220
230
240
Optional accessories
Anti-vibration grip, Dust cover attachment, Loop handle, Toolless wheel cover
GA5020C, GA5021C: Accessories for 125mm angle grinder
GA6020C, GA6021C: Accessories for 150mm angle grinder
Switch trigger
Electronic
control
Single-finger Large type
Dimensions: mm (")
Width (W)
Height (H)
Length (L)
Model No. GA5020C
GA5021C
GA6020C
GA6021C
390 (15-3/8)
139 (5-1/2) 169 (6-5/8)
120 (4-3/4)
L
H
W
GA5021C/GA6021C
GA5020C/GA6020C
Continuous Rating (W)
Voltage (V) Cycle (Hz) Input Output Max. Output (W)
120 ---12.5 1,000 2,20050/60
Current (A)
(The image above is GA5020C/GA6020C.)

P 2/10
Repair
[2] LUBRICATION
Lubricate the parts below in order to protect parts and product from unusual abrasion.
Put approx. 15g of Makita grease SG No.0 in the gear room of Gear housing.
Apply Makita Grease SG No.0 to the portions designated with the mark of . (Fig. 1)
[3] DISASSEMBLY/ASSEMBLY
[1] NECESSARY REPAIRING TOOLS
[3] -1. Armature, Small spiral bevel gear*2, Ball bearing 6000DDW
DISASSEMBLING
Fig. 2
Pan head screw
M5x18 (4pcs)
Tapping screw
5x25 (4pcs)
1) After removing Carbon brush, separate Gear housing
together with Armature from Motor housing complete
by unscrewing four M5x18 Pan head screws. (Fig. 2)
2) Separate Bearing box from Gear housing by unscrewing
four 5x25 Tapping screws. (Fig. 2)
CAUTION: Unplug the machine and remove the wheel and the wheel cover from the machine
for safety before repair/ maintenance in accordance with the instruction manual!
Code No.
1R004
Description
Retaining ring pliers ST-2
[1R291 can be used instead of 1R004.] Removal/installation of Ring spring 7
1R005 Retaining ring pliers RT-2N Removing Retaining ring R-30
Removing Large spiral bevel gear*1
1R045 Gear extractor (large)
1R346 Center attachment for 1R045
Removal/installation of Hex nut M7
Disassembling Shaft lock section
1R039 Armature holder 41.5 [one set required]
1R268 Spring pin extractor M3
1R269 Bearing extractor
Removing Lock sleeve and Lock spring 16--- Adjustable wrench
Removal/installation of Hex nut M7--- Wrench 11
Disassembling Shaft lock section1R350 Ring 60
Use for
Fig. 1
Large spiral bevel gear
Outside surface
Lock spring 1639
Surface that contacts Large spiral bevel gear
Spindle49
Item No. Description Portion to lubricate
39
49
Bearing box
Motor housing
complete
Gear housing
Removing Ball bearing 696ZZ
*1: Different spiral bevel gears are used by different models
as follows:
GA5020C and GA5021C/ Spiral bevel gear 35B
GA6020C and GA6021C/ Spiral bevel gear 38
*2: Different spiral bevel gears are used by different models
as follows:
GA5020C and GA5021C/ Spiral bevel gear 11
GA6020C and GA6021C/ Spiral bevel gear 11A

P 3/10
Repair
[3] -1. Armature, Small spiral bevel gear, Ball bearing 6000DDW (cont.)
DISASSEMBLING
ASSEMBLING
Fig. 8
Ball bearing 6000DDW
1) Mount Ball bearing 6000DDW on Armature by hand, then insert
into the bearing installation hole of Gear housing, (Fig. 8)
Then pull off Armature.
2) Put Flat washer 22 on Ball bearing 6000DDW, and fasten them
with Retaining ring R-30 using 1R005.
3) Then do the reverse of the disassembling steps.
1R269
Ball bearing 608DDW
3) Attach one set of 1R039 to vise, then fix Armature in 1R039.
Remove Hex nut M7 from the drive-end of Armature shaft by turning it counterclockwise with Wrench 11. (Fig. 3)
4) Hold Small spiral bevel gear by hand, then pull off Armature from Gear housing. (Fig. 4)
Note: If it is difficult to pull off Armature by hand, do the following steps.
1. Lubricate the gear and Armature shaft with spray lubricant.
2. Wrap the gear with cloth to protect the gear teeth.
3. Using water pump pliers or the like, firmly grip the gear wrapped with cloth, then turn the gear.
5) In order to remove Ball bearing 6000DDW from Gear housing,
first remove Retaining ring R-30 using 1R005, then remove
Flat washer 20 from Gear housing. (Fig. 5)
6) Reassemble Armature to Gear housing, then the spiral bevel gear
to Armature shaft. Tighten Hex nut M7 provisionally by turning
clockwise. (Refer to Figs. 4, 3)
7) By tapping the end surface of Gear housing with plastic hammer,
Ball bearing 6000DDW can be removed together with Armature.
(Fig. 6)
8) Remove Ball bearing 608DDW from Armature using 1R269. (Fig. 7)
Small spiral bevel gear
Fig. 3 Fig. 4
Hex nut M7 Small spiral bevel gear
Gear housing
Wrench 11
1R039
Fig. 6 Fig. 7
Hex nut M7
Ball bearing 600DDW
Ball bearing 6000DDW
Fig. 5
Retaining rig R-30
Flat washer 22
Ball bearing 6000DDW
Hex nut M7
Small spiral bevel gear

P 4/10
Repair
[3] -2. Large spiral bevel gear and Ball bearing 6002DDW
DISASSEMBLING
Fig. 11 Fig. 12
Fig. 9 Fig. 10
3) Remove Ring spring 7 from Spindle by levering up with slotted screwdriver while expanding the ends of the spring
a little bit with 1R004 or 1R291. (Fig. 11) Then remove Flat washer 8 and Lock washer.
4) As illustrated in Fig. 12, remove Large spiral bevel from Spindle together with Lock sleeve and Lock spring 16
using 1R045 and 1R346.
1) Separate Bearing box from Gear housing first by unscrewing four M5x18 Pan head screws then by tapping the end of
Gear housing with plastic hammer as illustrated in Fig. 9. It is not necessary to remove Carbon brushes.
2) Remove Ball bearing 6000ZZ using 1R269. (Fig. 10)
Note: The gear and the ball bearing can be replaced without disassembling the Motor section.
1R269
Ball bearing 696ZZ
Bearing box
Large spiral bevel gear
Gear housing
Bearing box
1R004
Ring spring 7 Spindle
Slotted screwdriver Bearing box
Spindle
Large spiral bevel gear
5) Hold Large spiral bevel gear securely by hand, and pull off Lock sleeve with adjustable wrench while turning it
counterclockwise. Then remove Lock spring 16 the same way as you removed Lock sleeve. (Fig. 13)
6) After removing Large spiral bevel gear, separate Bearing retainer 39 by removing three M3x6 Pan head screws. (Fig. 14)
Fig. 13
Large spiral bevel gear
Lock sleeve
Lock spring 16
1R045
1R346
Fig. 14
Pan head screw
M3x6 (3 pcs)
Bearing retainer 39

P 5/10
Repair
[3] -2. Large spiral bevel gear and Ball bearing 6002DDW (cont.)
DISASSEMBLING
Fig. 15 Fig. 16
Ball bearing
in Bearing box
7) Remove Ball bearing in Bearing box by hitting Bearing box straight down against flat surface of work-bench. (Fig. 15)
If cannot be removed, use arbor press and a round bar for arbor of an appropriate size as illustrated in Fig. 16.
Round bar for arbor
ASSEMBLING
Large spiral bevel gear
Lock spring 16
Fig. 17
Note 1: Ring spring 7 inevitably loses its elasticity when removed from Spindle. This will also happen to new one when
it is assembled to Spindle. Therefore, reuse removed Ring spring 7 if it is not damaged.
Do not forget to fasten Ring spring 7 securely to Spindle using pliers whether it is removed one or new one.
Note 2: Do as described in Fig. 17 when assembling Lock spring 16 and Lock sleeve to Large spiral bevel gear.
Do the reverse of the disassembling steps.
Put Lock spring 16 on the hole of Large spiral bevel gear,
then tap the top of the spring with plastic hammer
while gradually moving the impact point counterclockwise
until the spring does not move any further.
Put Lock sleeve over Lock spring 16, then tap the top
of the sleeve with plastic hammer as illustrated below
while gradually moving the impact point clockwise
until the sleeve does not move any further.
Lock sleeve

P 6/10
Repair
[3] -3. Shaft lock section
1) Remove Bearing box from Gear housing. (Fig.9on page 4)
2) Shoulder pin 5 can be removed from Gear housing using 1R268, 1R350 and plastic hammer as illustrated in Fig. 18.
DISASSEMBLING
Do the reverse of the disassembling steps.
Note: Do not reinstall removed Pin cap because removal of Shoulder pin 5 damages the inside surface of Pin cap.
Be sure to remove plastic dust of Pin cap from Shoulder pin 5 and to install it onto new Pin cap.
ASSEMBLING
Fig. 18
Pin cap
Gear housing
Shoulder pin 5
Compression spring 8
1R350
1R268
Pin cap
Gear housing
O ring 7
1R268
1R350

P 7/10
Circuit diagram
Field
*Noise suppressor is not used for some country.
Switch
Color index of lead wires' sheath
Fig. D-1
Black
Power supply cord
Terminal block
White
Orange
*Noise suppressor is not used for some country.Color index of lead wires' sheath
Black
White
Orange
Noise suppressor*
Pickup coil
Controller
GA5020C/ GA6020C
Fig. D-2
GA5021C/ GA6021C
black or brown
white or blue
Field
Switch
Power supply cord
Terminal block
Noise suppressor*
Pickup coil
Controller
black or brown
white or blue
red or purple or blue
Insulated connector
Insulated connector
Red

P 8/10
Fig. D-3
All models
Wiring diagram
[1] Motor housing
Route Field lead wires as illustrated below. (Fig. D-3)
Field lead wires
(orange, white)
Motor housing
opening
Route Field lead wires through this opening.
Pickup coil to which Sleeve is assembled
Motor housing,
viewed from [A]
rib
Pickup coil
to Controller
Sleeve
Before assembling Pickup coil to Motor housing,
route Lead wires of Pickup coil as described below:
1) Route beside the rib of Sleeve.
2) Then fix with the lead wire holder of Sleeve.
3) Make sure that Lead wires are tight.
lead wire holder
[A]

P 9/10
Wiring diagram
[2] Handle
Route Field lead wires as described below in Fig. D-4.
Fig. D-4
Terminal block
(h)(g)(a, b, c, d)
[1] Before routing Lead wires, adhere Sponge sheet
to the back of Terminal block as illustrated to right.
[2] Route the following Lead wires under Terminal block:
(a), (d), (g), (h), (k)
[3] Fix the following Lead wires with this Lead wire holder:
(a), (b), (c), (d)
[4] Fix the following Lead wires with this Lead wire holder:
(g), (h)
[5] Route the following Lead wires between the inside wall
of Handle and the rib for fixing Controller:
(e), (f); (g), (h)
[6] Put Noise suppressor in this portion if used.
[7] Put Insulated connector in this portion.
Handle
GA5020C/ GA6020C
(k)
(e, f)
Lead wires of Controller:
(a) White, to Insulated connector
(b) Black, to Terminal block
(c) Red, to Terminal block
(d) Orange, to No.1 Terminal of Switch
(e) Black, to Pickup coil
(f) White, to Pickup coil
Field lead wires:
(g) White, to Insulated connector
(h) Orange, to No.1 Terminal of Switch
Lead wires of Noise suppressor (if used):
(i) White, to Controller
(j) Black, to Controller
Relay wire:
(k) Black, from No.3 Terminal of Switch to Terminal block
Index of Lead wire
Insulated connector
[3][2]
Switch
Controller
(i, j)
Noise suppressor
(if used)
[4] [5]
[5][6][7]
rib for fixing
Controller
[1]
Terminal block
Sponge sheet

P 10/10
Wiring diagram
[2] Handle (cont.)
Route Field lead wires as described below in Fig. D-5.
Fig. D-5
Terminal block
(h)(g)(a, b, c, d)
[1] When connecting Lead wire (c) to No.4 Terminal of Switch,
insert it from the direction shown in the figure on right.
[2] Before setting Switch in place, fix the following Lead wires
with Lead wire holders under Switch:
(b), (d), (h)
[3] Put Insulated connector in this portion.
[4] Fix the following Lead wires with this Lead wire holder:
(a), (b), (c), (d)
[5] Fix the following Lead wires with this Lead wire holder:
(g), (h)
[6] Route the following Lead wires between the inside wall
of Handle and the rib for fixing Controller:
(e), (f); (g), (h)
[7] Put Noise suppressor in this portion if used.
Handle
GA5021C/ GA6021C
(k)
(e, f)
Lead wires of Controller:
(a) White, to Insulated connector
(b) Black, to No.3 Terminal of Switch
(c) Red or Purple or Blue,
to No.4 Terminal of Switch
(d) Orange, to No.2 Terminal of Switch
(e) Black, to Pickup coil
(f) White, to Pickup coil
Field lead wires:
(g) White, to Insulated connector
(h) Orange, to No.2 Terminal of Switch
Lead wires of Noise suppressor (if used):
(i) White, to Controller
(j) Black, to Controller
Relay wire:
(k) Black, from No.3 Terminal of Switch to Terminal block
Index of Lead wire
Insulated
connector
[4][3]
Switch
Controller
(i, j)
Noise suppressor
(if used)
[5] [6]
[6][7]
rib for fixing
Controller
[1]
No.4 Terminal (c)
Lead wire holders
(h)
(b), (d)
[2]