Hitachi F20a Manual

							MODEL    F 20A
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1 -
1. NOTES ON DISASSEMBLY AND REASSEMBLY
As notes concerning usage are presented in the Handling Manual,
notes on disassembly, assembly and repair are presented here.
The bottom surfaces of the front and rear bases must be kept
level and parallel at all times. The power source cord must be un-
plugged from the electric outlet during all disassembly, assembly and
repair procedures.
1-1. Set Gauge Adjustment
In addition to the items presented in the Handling Manual,
supplementary explanations are presented here.
Blade height adjustment gener-
ally means to set the tip of the
blade at the same surface of the
rear base. With this planer,
as shown in Fig. 2, a cartridge
type setting gauge is utilized.
With this type, the blade and
the blade metal are fixed at
Size L, which is previously
set on the setting gauge, and, as
shown in Fig. 1, the tip of the
blade is set at the location of
Size L prepared in the cutter
block. Taking the proper
L size means that the blade
Blade HolderCutter Block
Holder Spring
Face A
Blade
Front BaseRear Base
Blade
Metal
Fig. 1
L
BladeScrew
Minute
Adjusting
ScrewBlade MetalSet Gauge Face A
Fig. 2 
						

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can be at the same surface as the rear base.
However the L sizes in Fig. 1 and Fig. 2 are checked for
accuracy before the shipment, the L size in Fig. 2 has possi-
bility to differ from the L size in Fig . 1. For this reason, it is
necessary to ask customers to double check the L sizes in Fig. 1
and Fig. 2. The first time the customer removes the blade
holder and the L size in Fig. 2 must be checked to confirm that
it coincides with the L size in Fig. 1. The setting gauge should
be adjusted with the minute adjusting screw, as shown in Fig. 2,
if the L size in Fig. 2 does not coincide with the L size in
Fig. 1.
1-2. Disassembly (circled numbers denote the item number in the
Parts List)
A. Removing Armature 
12, Cutter Block 16 and
End Bracket 
28
1. First unscrew M4 plus head machine tapping screw 48
(2 pcs.), and remove tail cover 52.
2. Remove brush cap 
59 and carbon brush 58. Unscrew
M4 plus head machine tapping screws 
53 (2 pcs.), and
bearing Cover 
27.
3. Unscrew M4 plus head machine tapping screws 
29
(5 pcs.), which fix end bracket 28 to housing 1, and 
						

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armature 12 and cutter block 16 are extracted
together with end bracket 
28, by lightly pounding the
shaft of armature 
12 and the end of spindle cutter
block 
16 with a wooden hammer, the fitting the handle
of a box spanner, or some similar instrument.
B. Removing the Stator
1. After removing the stator, the handle cover is removed
by unscrewing M4 plus head machine tapping screws 
29.
(4 pcs.).
2. Then, cut the connector (of the lead wire from cord 
43,
condenser 
41, and stator 4) as close to the base as
possible.
3. After unhooking the CB terminal of stator 
4 which is
hooked on the CB tube, M4 x 55 plus head machine
screws 
8 (2 pcs.) which fix stator 4 on housing 1 are
removed. Stator 
4 can be removed by setting the
contact face with end bracket 
28 of housing 1 down-
ward, and tapping the surface lightly with a wooden
hammer.
C. Removing Pulley (A) 
54 and Pulley (B) 55
1. Remove belt cover 57 from end bracket 28 by unscrew-
ing M4 plus head machine tapping screw (1 pc.). 
						

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2. Pulley (A) 54 and pulley (B) 55 are screwed (right
hand screw and left hand screw respectively) on the
armature shaft and the cutter spindle. Pulley (A) 
54
is removed by setting a spanner on the pulley, holding
armature 
12 firm with a vise, and rotating the spanner
in the clockwise direction.
3. Pulley (B) 
55 is removed by setting a spanner on the
pulley, holding the cutter block firm with a vise, and
rotating the spanner in the counterclockwise direction.
It is thick rag to prevent injury to fingers and hands.
D. Removing Front Base 
32 and Rear Base 50
Front base 32 is removed by rotating knob 36 in the
counterclockwise direction. Rear base 
50 is removed by
unscrewing M4 plus head machine tapping screws 
48
(4 pcs.) which are screwed on the housing.
1-3. Reassembly
The reassembly procedure is the reverse of the disassembly
procedure. It is necessary to feed lubrication oil (Shell Machine
Oil No. 68) at the fitting point with the housing when fitting a new
(spare) front base.
1-4. Insulation test
After overhaul, measurement of insulation resistance and
insulation testing must be accomplished.