Akai X-2000SD - Page 14

Vi. MECHANISM ADJUSTMENT
1. PINCH WHEEL ADJUSTMENT
It is important that the pinch wheel shaft be kept in
perfect alignment with the capstan shaft. Proper pinch
wheel pressure is between 1,000 and 1,150 grams when
the unit is operated at the tape speed of 7-1/2 ips. Any
deviation from this specification will result in wow and
flutter. Check pinch wheel pressure by a spring scale,
and if necessary, adjust the pinch wheel load spring.
2. TAKE-UP IDLER WHEEL ADJUSTMENT
The take-up idler wheel must be kept in perfect
alignment with the take-up reel shaft. In fast forward
operation, the idler wheel contacts the upper knurled
wheel of the take-up reel shaft assembly, and conversely
contacts the lower knurled wheel during record or play
operation. Adjust idler wheel load spring so that the
idler wheel pressure is kept between 50 and 80 grams.
The idler wheel wears rapidly if the pressure is excessive.
Slippage occurs if the pressure is less than specified.
(a) Rewind reel shaft assy.
|
(b) Take-up reel shaft assy.
reel shaft
reel table reel stopper
ree] table base plate
felt clutch
—drive shaft
rewind pulley : ee
conical sprin, =
pring metal washer
felt clutch ——retainer
GER take-up
washer <=. drive wheel
~olg--Star-shaped spring
washer —~-==—> metal washer
retainer —-2=> nylon washer
1
tne oat = <=
oilite metal mtg, plate G-~oilite metal it
star-shaped —onn . -
spring for brake | --——Paper washer coil spring
set retainer wasner
+—pulley B =5—— retainer
| ie nylon
ape —— washer
w2set sleeve
Fig. 1
3. REWIND IDLER WHEEL ADJUSTMENT
The rewind idler wheel must be kept in perfect
alignment with the rewind reel shaft. The amount of
pressure on the knurled motor bushing should be about
50 grams during rewind operation. Adjust both the idler
load spring and rewind roller.
12
4. INTERMEDIATE WHEEL ADJUSTMENT
The intermediate wheel is located between the rewind
idler wheel and the rubber ring which is used on the
upper part of the supply reel shaft assembly. In rewind
condition, it contacts these parts while simultaneously
transmitting motor torque. An adequate pressure is 50
grams. Adjust the load spring of the intermediate
wheel if the pressure is not sufficient.
5. TAKE-UP REEL SHAFT ASSEMBLY
ADJUSTMENT
Felt clutch material is attached to the bottom side of the
reel table base plate so that recording tape will not
stretch during fast forward operation due to excessive
tension. To check the amount of friction of this part,
install a 5-inch reel with a 60 m/m diameter tape, and
gently pull the end of tape upward with a spring scale.
Adjust the conical spring so that the amount of tension
at this part is kept between 400 and 500 grams. Other
felt clutch material is attached to the take-up drive
wheel. This is to provide proper slippage during record
or play operation. The procedure for checking friction
of this part is the same as the foregoing, and between
150 and 200 grams of friction provides the best results.
Adjust the star-shaped spring just under the take-up
drive wheel. When the unit is set to rewind operation,
the amount of friction of this part will decrease to from
15 to 20 grams. Check to see whether this is satisfactory.
If not, readjust the star-shaped brake spring and the
pressure of the spring retainer washer accordingly.
6. SUPPLY REEL SHAFT ASSEMBLY
ADJUSTMENT
Felt clutch material is used between the lower side of
the reel table base plate and the rewind rubber ring to
protect recording tape from excessive tension during
rewind operation. To check the amount of friction of
this part, place onto the supply reel table a 5-inch reel
with a 60 m/m diameter tape, and gently pull the end of
tape upward with spring scale. Adjust the conical spring
so that the amount of tension is kept between 400 and
500 grams. Other felt clutch material is attached to the
rewind drive wheel to provide proper slippage during
record or play operation. The procedure for checking
friction of this part is the same as the foregoing, and
between 100 and 125 grams of friction gives best results.
When the unit is set to fast forward operation, the
amount of friction will decrease to from 15 to 20 grams.
Check to see whether this is correct. If not, readjust coil
spring and spring retainer washer. (See figure 1 (a) at
left)