Singer 7285Q User manual

Page 1/38
Original issue
May, 2014
Service Manual
7285Q
Model
Original issue: May 2014
Jaguar International Corporation

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Original issue
May, 2014
Service Manual
7285Q
Model
INDEX
1. Disassembling of covers
2. Adjustment of feed dog height
3. Needle bar height
4. Needle threader height
5. Presser foot height and direction
6. Needle position at zigzag stitching
7. Clearance between needle and shuttle
8. Needle timing to feed dog
9. Needle timing to shuttle hook
10. Adjustment of thread tension
11. Tension of timing belt
12. Motor belt tension
13. Retaining bracket for bobbin case
14. Origin point positioning of zigzag bight
15. Stitch length
16. Needle stop at highest position
17. Electronic component area
*AC Power board
*CPU /switch board
18. Wiring diagram
19. Part list for feed control unit
20. Helpful messages (Supplement)*

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May, 2014
Service Manual
7285Q
Model
1. Disassembling of covers
(1) Face cover side
(2) Bottom cover side
A
B
Remove screwA.
Remove screw B.
Loosen five screws.

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1. Disassembling of covers –continued--
(3) Back cover side
Remove two self-tapping screws.
Remove two screws.
Remove self-tapping screw.

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Service Manual
7285Q
Model
1. Disassembling of covers –continued--
(4) Front cover side
A
Push up front cover to open inserting
small screw driver between front and
back covers.
Loosen screw A.
Open back and front covers.

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Service Manual
7285Q
Model
1. Disassembling of covers–continued--
.
Pull out front cover.
Open mating portion of front and back
covers using small screw driver.
Push back cover by small screw driver.
Force front cover open by small screw driver.

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May, 2014
Service Manual
7285Q
Model
1. Disassembling of covers –continued--
Force front cover open by small screw driver.
Lift up front cover as below.

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2. Adjustment of feed dog height
Checking:
1. Move feed dog to its highest position by turning hand wheel.
Check to see if feed dog height is as illustrated below.
Adjustment:
1. Remove needle plate. Loosen nut with wrench.
2. Adjust height by turning screw as illustrated. Tighten nut securely after adjustment.
0.9 – 1.1 mm

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Service Manual
7285Q
Model
3. Needle bar height
Note: Make this checking before checking “Needle timing to shuttle” and
”Feed-dog timing (vertical motion)”.
Checking:
1. Select straight stitch at center needle position.
2. Remove presser foot and needle plate, and then remove bobbin case.
3. Replace needle with special needle gauge (L=29 mm).
4. Lower the needle gauge to its lowest position by turning hand wheel by hand.
Check to see if the bottom of the needle gauge aligns with shuttle race pushing
the needle lightly as shown by arrow mark.
Adjustment:
1. Remove face cover.
2. Loosen screw (A) of needle bar clamp using hex screw driver
and adjust the height of needle bar.
Lowest position of
Needle
Needle position
at center
A
Needle gauge L =29 mm
Shuttle race

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Service Manual
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Model
3. Needle bar height –continued--
3. Tighten the screw (A) securely after adjustment. Replace needle gauge with
normal needle #90/14.
4. Check to see if needle threader operates correctly and there is not interference in
vertical movement of needle bar.

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May, 2014
Service Manual
7285Q
Model
4. Needle threader height
1. Use needle Singer 90/14.
2. Select straight stitch at center needle position.
3. Raise needle to its highest position by turning hand wheel toward you.
4. Lowering needle threader lever, check and see if hook is inserted into needle hole.
Adjustment
1. Remove face cover.
2. Turning hand wheel by hand, raise needle bar (A) to its highest position.
3. Loosen screw (B) of threader stopper.
4. Insert hook into the upper side of needle-hole moving the needle threader bar
(C).
5. While holding the above situation, tighten the screw (B) attaching the stopper
pin (D) onto threader stopper (E).
6. The direction of screw (B) on threader stopper (E) should be facing toward
you so that it may not hit the needle support bracket.
＊Insert the hook into the upper side of needle hole at all times as the smaller
needle size, the shorter needle hole.
A
B
Insert the hook into the
upper side of needle hole.
90/1
80/1
70/9
Hook
D
B
A
C
E

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Service Manual
7285Q
Model
4. Needle threader height --continued--
7. If the direction of insert hook is deviated from correct position, adjust the hook
position with the small screw driver in the accessory.
8. Recheck that the needle threader works correctly.
Needle hole
Hook

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Service Manual
7285Q
Model
5. Presser foot height and direction
Checking
1. Lower the feed dog below the needle plate.
2. Raise the presser foot lever.
3. Check and see if clearance between the needle plate and the presser foot is about
5.6 mm.
Adjustment
1. Remove the face cover, and raise the presser foot lever.
2. Loosen the screw (A) and adjust the presser foot height moving the presser bar.
3. Tighten the screw securely after checking the presser foot is parallel with the holes for
feed dog on the needle plate.
5.6 mm
A
A

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Service Manual
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Model
6. Needle position at zigzag stitching
Checking:
1. Select widest zigzag stitch.
2. Turn hand wheel by hand and see if needle leaves the same clearance at both right
and left end of needle plate hole.
Adjustment:
1. Loosen screw by hex screw driver and adjust needle position by turning eccentric
pin (A) using 7mm wrench.
b
a
a＝b
A
Hex screw driver
At left position
At right position

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Service Manual
7285Q
Model
7. Clearance between needle and shuttle
Make this checking before checking “Needle timing to shuttle”.
Checking:
1. Select widest zigzag stitch.
2. Remove needle plate, bobbin case and face cover.
3. Shift shuttle hook at the rear of needle by turning hand wheel.
Check to see if needle clearance to shuttle is within 0.05 to 0.15 mm.
Adjustment:
1. Turn screw (A) to either direction as illustrated and adjust needle position by moving
support shaft back and forth. To decrease clearance, turn screw counter-clockwise.
Shuttle
0.05
～
0.15
ｍｍ
0.05
～
0.15
ｍｍ
At left position
At right position
0.05
～
0.15
ｍｍ
At left position At right position
A

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7. Clearance between needle and shuttle --continued--
2. If needle clearance to shuttle at right and left position is not same, adjust position
of fulcrum for needle swing support .
Loosen bolt (A) located under bottom of support plate and adjust position of fulcrum.
3. After adjustment, tighten the bolt (B) securely.
Position of fulcrum (B)
for needle swing support .
Do not loosen this screw.
B B B
If needle touches with shuttle at left side,
adjust position of fulcrum (B) for needle
swing support to the right.
If it touches at right side, adjust position
of fulcrum (B) for needle swing support
to the left.
C
B

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May, 2014
Service Manual
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Model
8. Needle timing to feed dog
Note: After adjustment, be sure to follow “Needle timing to shuttle”.
As horizontal and vertical feed motion is unitized on this model, adjustment of feed
timing is as follows:
Checking:
1. Select straight stitch at maximum stitch length.
2. Bring needle bar to its highest position by turning hand wheel.
3. Check to see if feed dog starts to move when needle starts to go down by
turning hand wheel towards you.
Adjustment:
1. Adjust the angle of timing gear to lower shaft with 2 screws (A1 & A2) on timing gear
loosened and hex driver inserted into one of the screws by turning main shaft with hand
wheel,.
If feed-dog motion too early → Turn hand wheel towards you.
If feed-dog motion too late → Turn hand wheel away from you.
2. Tighten one of two screws temporarily and check feed-dog motion.
3. After adjustment, tighten screws (A1 & A2) securely.
Feed dog starts to move a little bit
earlier than when needle starts to
go down.
A 1
A 2

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Service Manual
7285Q
Model
9. Needle timing to shuttle hook
Check “Feed timing (vertical movement)” and “Needle height” beforehand.
Checking
1. Select widest zigzag stitch.
2. Remove needle plate. Check to see if needle is not bent.
3. Move needle to left position by turning hand wheel. Raise needle from its lowest
position slowly and check if distance is as illustrated below when point of shuttle
hook aligns with right side of needle.
Adjustment
1. Remove front cover. Loosen two screws (A & B) on gear and adjust position
of gear as illustrated below.
With one screw tightened temporarily, check to see if the distance is as illustrated
above. Adjust it by turning main shaft with hand wheel, with screws loosened and
hex driver inserted into one of the screws.
0.5 to 1.2
Needle plate
Shuttle race
point of shuttle hook
A
B

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Service Manual
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Model
9. Needle timing to shuttle hook --continued--
2．Tighten screws securely after adjustment.
Meshing condition of shuttle race gear and lower shaft gear
1. Check meshing condition of gear (A) after adjustment.
Check play of the gear at 4 positions –each 90 degree angle of 1 rotation of shuttle
race.
No play on 2 positions to save too loose condition – play on other 2 positions to
save too tight condition.
2. Adjustment of play between shuttle gear and lower shaft gear is made by turning
eccentric ball bushing (D).
*loosen screw (C) on pressing plate so that the ball bushing (D) may be turned.
*Turn the ball bushing (D) in either way by using concave portion.
*The ball bushing is to be placed with mark (F) positioned at upper side within angle of
180 degrees
3. Tighten the screw (C) securely after adjustment.
D
F
C
E

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Service Manual
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Model
10. Adjustment of thread tension
Checking:
1. Set thread tension at the center of “AUTO” position.
2. Pull thread between tension discs and check thread tension value with two twisted
Polyester #50 thread.
3. Measured value should be 40 to 50 g.
* Bobbin thread tension should be 12 to 16 g.
* For actual sewing, sew zigzag stitch and check balance of upper and lower threads.
Adjustment:
1. Raise take-up lever to its highest position by turning hand wheel by hand.
2. Set thread tension at the center of “AUTO” position. Insert your forefinger from the rear
of thread guide plate and rotate toothed plate (A) to adjust spring in either direction.
3. Viewing the toothed plate (A) from face cover side,
*Rotate it counter-clockwise when increasing thread tension.
*Rotate it clockwise when decreasing thread tension.
A
Thread tension is increased
Position of spring adjustment plate (A)