Akai M-9 - DRIVING OF CAPSTAN; DRIVING OF PINCH WHEEL; RECORDING AND PLAYBACK

DRIVING OF CAPSTAN
Figure 1.
(A) Motor
(B) Driving Belt (flat belt)
(C) Capstan
(D) Flywheel
High-speed rotation of Motor (A) is reduced by Driv-
ing Belt (B) and transmitted to Capstan (C), which is
connected with flywheel with ample inertia. This
enables the rated rotation to be attained by absorbing
| minor rotation distortion of motor itself.
Capstan Rotation: 3
Fig. 1 606 R.P.M. at 7-1/2" (19 cm) per sec.
303 R.P.M. at 3-3/4" (9.5 cm) per sec.
151.5 R.P.M. at 1-7/8" (4.75 cm) per sec.
Motor Rotation:
3,000 to 1,500 R.P.M. at 50 cps.
3,600 to 1,800 R.P.M. at 60 cps.
DRIVING OF PINCH WHEEL
Put tape between rotating capstan and pinch wheel,
and push the pinch wheel against the capstan. This
will transport the tape at rated speed. The appro-
priate pressure of pinch wheel is between 1,000 and
1,150 grams at the tape speed of 7-1/2” (19 cm)
per second.
RECORDING AND PLAYBACF.
Turn the RECORD/PLAYBACK KNOB(A)to*‘PLAY”
position, and pinch wheel presses against capstan to
move tape at the rated speed. At the same tirne, Idler
(b)moves between Motor Bushing (C) and the Take-Up
7 Reel Spindle (D) to transmit the motor rotation to(D)
Braked Rotation E e so that the tape is moved and wound on the take-up
reel,
The Take-up Reel Spindle Base is made up of two
plastic rollers (1 and 2) with a clutch felt inbetween.
The Idler is rotating the plastic roller (2) underneath.
Therefore, the tape-winding friction is adjusted by the
slipping of the felt to maintain the rated winding of
the tape. On the other hand, the Supply Red Spindle
(H) has a Brake Roller (E) hung on the Plastic Roller
(4) underneath, which provides approptite back
tension by the clutch felt slipping to the ro:ation of
the Pulley (3) above.
To prevent accidental erasure, the Record Imterlock
Button (F) must be depressed before the RECORD/
PLAYBACK KNOB can be moved to the “REC” posi-
tion. The Safety device (G) is depressed to operate
the recording mechanism.
(See Figure 2)