Position And Function Of The Eccentrics - ELNA 745 Service Manual

ANGULAR POSITION OF BALANCE WEIGHTS AND POSITION OF
ECCENTRICS
1. Remove: Mains lead - Back - Front cover - Machine base.
2. In case of dismantling the lower shaft or if one of the eccentrics is damaged or badly
fixed, the positions shown in page 3a, allow resetting the eccentrics approximately. These
should be adjusted correctly with each relative adjustment. Each angular position of
eccentrics as shown is based primarily on the angular positions of screw "a" of main shaft
collar. It is useful to turn handwheel by (90 ) to check the correct position of the
eccentrics. See procedure shown below.
3. Check and set screw "a" of collar "2" at the same level of the screw of needle bar timing
eccentric "1".(Fig.5) Turn the handwheel toward you and check if the screw on collar
"2" is set at the same level of eccentrc "3".(Fig.4)
4. Turn handwheel towards you and bring needle bar to its highest postion. Check if the
balance weight "A" is positioned as shown in Fig. 1.
@Note: If position of eccentrc "3" is correctly set, it is possible to see the screw of eccentric
"3" from the opening on the thread take up rotary cam when needle bar is set in its
highest position.
5. Turn handwheel towards you and chec if the eccetric "7" and the balance weight "8" are
positioned as shown in Fig. 2
6. Turn handwheel (180 ) counterclockwise and check position of balance weight "8" and
eccentric screws "6-7".(Fig.3)
7. Turn handwheel (90 ) clockwise and check position of screw on collar "2" and eccentric
screw "3".(Fig.4)
8. Turn handwheel (90 ) counterclockwise and check position of screw "a" of collar "2"
with eccentric "1-5-6".(Fig.5)
9. Turn handwheel (90 ) counterclockwise and check position of eccentric screws "1-4".
(Fig.6)
10. Turn handwheel (90 ) counterclockwise and check position of eccentric screws"4".(Fig.7)

Position and function of the eccentrics:

1) Needle bar timing
2) Main shaft collar
3) Horizontal feed eccentric
4) Upper looper timing
5) Lower looper and chain looper timing
6) Orbital motion of chain looper
7) Moving cutter and vertical feed timing
8) Balance weight
3b