Baby Lock BL9 Troubleshooting guide

SERVICING MANUAL
&
PARTS LIST
(MODEL BL9)
BABYLOCK

CONTENTS
TROUBLESHOOTING............................................................................................... 1–3
SERVICE ACCESS
FACE COVER / BELT COVER .................................................................................. 4
BASE PLATE ............................................................................................................. 5
FRONT COVER ......................................................................................................... 6
REAR COVER ........................................................................................................... 7
MECHANICAL ADJUSTMENT
TOP TENSION ........................................................................................................... 8
BOBBIN TENSION..................................................................................................... 9
PRESSER BAR HEIGHT AND ALIGNMENT ............................................................ 10
NEEDLE SWING........................................................................................................ 11
NEEDLE DROP ......................................................................................................... 12
CLEARANCE BETWEEN NEEDLE AND HOOK (ADJUSTMENT METHOD NO. 1) 13
CLEARANCE BETWEEN NEEDLE AND HOOK (ADJUSTMENT METHOD NO. 2) 14
FEED DOG HEIGHT ................................................................................................. 15
NEEDLE BAR HEIGHT .............................................................................................. 16
NEEDLE TIMING TO SHUTTLE ................................................................................ 17
BUTTONHOLE FEED BALANCE .............................................................................. 18
FEED BALANCE ON STRETCH STITCH ................................................................. 19
BARTACK FEED OF BUTTONHOLE ........................................................................ 20
DISENGAGEMENT OF CAM FOLLOWER ............................................................... 21
MOTOR BELT TENSION ........................................................................................... 22
WIRING .................................................................................................................. 23
PARTS LIST .................................................................................................. 24-41

1
MODEL BL9
TROUBLESHOOTING
PROBLEM CAUSE REMEDY REFERENCE
1. Skipping 1. Needle is not inserted Insert the needle properly.
stitches properly.
2. Needle is bent or worn. Change the needle.
3. Incorrectly threaded Rethread.
4. Needle or thread are Use the recommended sewing
inappropriate for fabric being needle and thread.
sewn.
5. Sewing on stretch fabric Use A #11 blue tip needle.
6. Inappropriate needle bar See mechanical adjustment P. 16
height “Needle bar height.”
7. Inappropriate needle to hook See mechanical adjustment P. 17
timing “Needle timing to shuttle.”
8. Inappropriate needle to hook See mechanical adjustment P. 13, 14
clearance “Clearance between needle and
hook.”
2. Fabric not 1. Incorrect feed dog height See mechanical adjustment P. 15
moving “Feed dog height.”
2. Thread on bottom side of Make sure to bring both needle
fabric is jammed up. and bobbin thread under the foot
when starting sewing.
3. Feed dog teeth are worn. Change the feed dog.

2
MODEL BL9
PROBLEM CAUSE REMEDY REFERENCE
3. Breaking 1. Initial sewing speed is too fast. Start with medium speed.
upper thread
2. Thread path is incorrect. Use the proper thread path.
3. Needle is bent or dull. Replace with a new needle.
4. Upper thread tension is Adjust upper thread tension P. 8
too strong. correctly.
5. Needle size is inappropriate Use appropriate needle and
for fabric. thread for fabric in use.
6. Needle eye is worn. Change the needle.
7. Needle hole in needle plate is Repair the hole or replace the
worn or burred. needle plate.
4. Breaking 1. Incorrectly thread bobbin case. Thread bobbin case correctly.
bobbin thread
2. Too much thread is around on Adjust the position of stopper.
the bobbin.
3. Lint is stuck inside the hook Clean the hook race.
race.
4. Thread quality is too low. Change to a high quality sewing
thread.
5. Thread is jamming around the Clear out the jamming thread.
bobbin.
6. Bobbin thread tension is too Adjust bobbin thread tension P. 9
strong. correctly.
5. NEEDLE 1. Needle is hitting the needle See mechanical adjustment P. 12
BREAKS plate. “Needle drop .”
2. Needle is bent or worn. Change the needle.
3. Needle is hitting the hook race. See mechanical adjustment P. 13, 14
“Clearance between needle and
hook .”
4. The fabric moves while the See mechanical adjustment P. 11
needle is piercing it, or the “Needle swing.”
needle zigzags while in fabric.
5. Fabric is being pulled too Guide the fabric gently while
strongly while sewing. sewing.

3
MODEL BL9
PROBLEM CAUSE REMEDY REFERENCE
6. Noisy 1. Backlash between shuttle hook See mechanical adjustment P. 14
operation gear and lower shaft gear is “Clearance between needle and
too great. hook (NO. 2).”
2. Lower shaft gear is loose. Eliminate the looseness.
3. Inappropriate belt tension. See mechanical adjustment P. 22
“Motor belt tension.”
4. Upper shaft gear is loose. Eliminate the looseness.
5. Not enough oil. Oil all moving parts.
7. Deformation of 1. Inappropriate zigzag See mechanical adjustment P. 11
pattern synchronization. “Needle swing.”
2. Inappropriate disengagement See mechanical adjustment P. 21
of cam follower. “disengagement of cam follower.”
3. Upper thread tension is too Adjust upper thread tension P. 8
strong. correctly.
4. Inappropriate feed balance See mechanical adjustment P. 19
BALANCE "Feed balance on stretch stitch."

4
MODEL BL9
SERVICE ACCESS
FACE COVER
1. Remove the face cover by removing the setscrew (A).
BELT COVER
1. Loosen setscrew (B).
2. Take the belt cover out.
( B)
(B)
Belt cover
(A)
Face cover

5
MODEL BL9
SERVICE ACCESS
BASE PLATE
(To remove)
1. Loosen the setscrews (A).
2. Remove the base plate.
(To attach)
3. Mount the base plate by four setscrews.
Base plate
(A)

6
MODEL BL9
SERVICE ACCESS
FRONT COVER
(To remove)
1. Remove the face cover, and remove the belt cover (See page 4).
2. Remove dials (A) and ( B).
3. Loosen setscrews (C), (D), (E), (F), and (G) and then, remove the front cover by removing
setscrews (H), (I), AND (J).
NOTE: Remove the front cover in the order of (K).
(To attach)
4. Mount the front cover in reverse procedure of the removing.
(A)
(I)
(J)
(K)
(H)
(E)
(F)
(G)
(D)
Front cover
(C)
(B)
Cap

7
MODEL BL9
SERVICE ACCESS
REAR COVER
(To remove)
1. Remove the face cover and belt cover (See page 4).
NOTE: Pull up the spool pins.
2. Loosen setscrews (A), (B), (C) and (D) (2 pcs.), and then, remove the rear cover by removing
setscrews (E), (F), (G) and (H).
NOTE: Remove the rear cover in the order of (X) (lower part) (Y) (upper part) (Z) (presser
foot lifter part). (remove the bed cover together.)
(To attach)
3. Mount the rear cover in reverse procedure of the removing.
(A)
(B)
(C)
(F)
(E)
Rear cover
(D)
(H)
(G)
(Y)
(X)
(Z)
Cap

8
MODEL BL9
MECHANICAL ADJUSTMENT
TOP TENSION
To check:
The standard upper thread tension should be 65–95 g when pulling the thread (cotton thread #50)
in the direction of (B) with setting the tension dial at “3.” (make sure the foot should be lowered.)
If the tension is out of the standard range, adjust it as follows:
Adjustment procedure:
1. Remove the front cover unit (See page 6).
2. Turn the adjusting nut (C) in the direction of (D) when the upper thread tension is too tight.
Turn the adjusting nut (C) in the direction of (E) when the upper thread tension is too loose.
3. Attach the front cover unit.
(B)
(C)
(E)
(D)

9
MODEL BL9
MECHANICAL ADJUSTMENT
BOBBIN TENSION
To check:
Set the bobbin in the bobbin case and pass the thread (cotton #50) through the tension spring.
The bobbin thread tension should be 45–55g when pulling the thread in the direction of (B).
If the tension is out of the range, adjust it as follows:
Adjustment procedure:
1. Turn the adjusting screw (C) in the direction of (D) when the bobbin thread tension is too tight.
2. Turn the adjusting screw (C) in the direction of (E) when the bobbin thread tension is too
loose.
(B)
(E)
(D)
(C)
Cotton thread #50

10
MODEL BL9
MECHANICAL ADJUSTMENT
PRESSER BAR HEIGHT AND ALIGNMENT
To check:
1. Raise the presser foot lever (A).
2. The distance between the presser foot (D) and the needle plate (E) should be 6.0 mm (0.24").
Adjustment procedure:
1. Remove the face cover (See page 4).
2. Remove the presser foot lever and loosen the screw (C) on the presser bar holder.
Adjust the distance between the presser foot (D) and the needle plate (D) to 6.0 mm (0.24").
3. Tighten the screw (C) securely.
4. Tighten the screw (B) to secure the lamp socket.
5. Attach the face cover.
NOTE: When you tighten the screw (B), make sure that both sides of the
presser foot are parallel to the feed dog slots (F) on the needle plate.
(C)
(A)
(D)
(E)
(F)
6.0 mm
(B)

11
MODEL BL9
MECHANICAL ADJUSTMENT
NEEDLE SWING
To check:
Adjust the needle swing according to the following procedure, If the needle bar starts moving
sideways while the needle is in the fabric at sewing the zigzag pattern (with maximum zigzag
width).
Adjustment procedure:
1. Set the pattern selector dial with maximum zigzag width, and remove the front cover (See
page 6).
2. Loosen two screws.
3. Adjust the needle swing by turning the handwheel, while holding the worm so as not to
rotate it, until the needle swing starts at 2–3 mm on the needle plate after the needle has
come out of the right side of the needle hole.
4. Tighten two screws.
5. Mount the front cover.
NOTE: After adjusting the needle swing, check that the upper shaft worm and gear rotate
smoothly without any backlash between them.
Upper shaft worm
Gear
Screw
(2pcs.)
2–3 mm

12
MODEL BL9
MECHANICAL ADJUSTMENT
NEEDLE DROP
To check:
When the needle swings in maximum zigzag width, the distance between both ends of the needle
hole on the needle plate and the needle drop positions should be equal.
If not, adjust as follows:
Adjustment procedure:
1. Remove the face cover (See page 4).
2. Set the pattern selector dial at maximum zigzag width.
3. Loosen the screw.
4. Turn the eccentric pin to adjust the needle drop.
5. Tighten the screw.
6. Attach the face cover.
NOTE: Check the hook timing after this adjustment.
Eccentric pin
Screw
Both clearances should be equal

13
MODEL BL9
MECHANICAL ADJUSTMENT
CLEARANCE BETWEEN NEEDLE AND HOOK (ADJUSTMENT METHOD NO. 1)
To check:
The clearance between the needle and shuttle race should be –0.05 to +0.10 mm.
If not, adjust as follows:
Adjustment procedure:
1. Remove the face cover (See page 4).
2. Set the pattern select dial at " ".
3. Loosen screw (A), and move the needle bar supporter in the direction of the arrows to get a
clearance between –0.05 to +0.10 mm.
* If clearance is too wide, move the needle bar supporter to
direction (B).
* If clearance is too narrow, move the needle bar supporter to
direction (C).
NOTE:After this adjustment, check that the clearance between the needle and needle plate is
more than 0.15 mm as shown in figure (D).if not, adjust the clearance between needle
and shuttle race by using adjustment method, above after readjust the clearance
between needle and needle plate more than 0.15 mm.
4. Attach the face cover.
Screw (A)
Direction (C)
Direction (B)
Needle bar supporter
–0.05 TO +0.10 mm
Figure (D)
Clearance between needle and
needle plate should be at least 0.15 mm

14
MODEL BL9
MECHANICAL ADJUSTMENT
CLEARANCE BETWEEN NEEDLE AND HOOK (ADJUSTMENT METHOD NO.2)
To check:
Use this adjustment method NO. 2 when method NO.1 cannot be used.
The clearance between the needle and shuttle race should be –0.05 to +0.10 mm.
Adjustment procedure:
1. Set the pattern selector dial at " ".
2. Remove the rear cover (See page 7).
3. Loosen the screw (A) on the lower shaft bushing and slide the gear about 0.5 mm to the
right to create some slack between the gears.
4. Lower the needle and loosen the two shuttle race screws (B).
Move the shuttle race unit axially either forward or backward to adjust the clearance
between the needle and the shuttle race in the range of –0.05 to +0.10 mm.
5. Set the pattern select dial at " ", turn the handwheel to check if the clearance between
the needle and inner edges of the shuttle race spring at the left and right needle drops are
equal.
If not, adjust by turning the shuttle race unit.
6. Tighten the two shuttle race screws (B).
7. Loosen the set screw on the lower shaft bushing and slide the gear back to the original
position while adjusting the backlash.
8. Tighten screw (A) firmly.
9. Attach the rear cover.
NOTE: The backlash play should be less than 0.3 mm and the lower shaft should turn
smoothly.
After the adjustment, check the hook timing.
–0.05 to
+0.10 mm
Clearance should be equal
Shuttle race
screws (B) (2 )
Lower shaft
bushing (front)
Needle
Shuttle race spring
Screw
(A)

15
MODEL BL9
MECHANICAL ADJUSTMENT
FEED DOG HEIGHT
To check:
1. Lower the presser foot.
2. Turn the handwheel toward you until the needle bar comes to the feed dog above the
needle plate should be 0.75–0.90 mm.
If it is not in the range, adjust as follows.
Adjustment procedure:
1. Open the shuttle cover.
2. Lower the presser foot and turn the handwheel toward you until the feed dog comes to its
highest point.
3. Loosen the screw (A) .
4. Turn the feed lifting pin to adjust the height of feed dog (0.75–0.90 mm).
5. Tighten the screw (A).
6. Turn the handwheel toward you to recheck the height of feed dog.
Screw (A)
Feed lifting pin
0.75–0.90 mm
Needle plate

16
MODEL BL9
MECHANICAL ADJUSTMENT
NEEDLE BAR HEIGHT
To check:
When the tip of shuttle hook meets the left side of the needle in ascending travel of the
needle from its left and lowest position, The distance between the top of the needle eye and
the tip of the shuttle hook should be in the range of 2.9-3.5 mm.
Adjustment procedure:
1. Open the face cover.
2. Set the pattern selector dial at " ".
3. Open the shuttle cover.
4. Remove the shuttle race ring.
5. Turn the handwheel toward you until the tip of the shuttle hook meets the left side of the
needle.
6. Loosen the lower shaft crank arm screw (A).
7. Adjust the height of the needle bar by moving the needle bar upward or downward without
turning it.
8. Tighten the screw (A).
9. Attach the shuttle race ring.
Screw (A)
Needle bar
Tip of shuttle hook meets
left side of needle
2.9–3.5 mm

17
MODEL BL9
MECHANICAL ADJUSTMENT
NEEDLE TIMING TO SHUTTLE
To check:
The height of the needle point from its lowest point of travel should be in the range of 1.45-
1.95 mm when the tip of the shuttle hook just meets the left side of the needle at the left
needle position.
Adjustment procedure:
1. Set the pattern selector dial at “ ”.
2. Remove the base (See page 5).
3. Open the shuttle cover.
4. Remove the shuttle race ring.
5. Turn the handwheel toward you until the tip of the shuttle hook meets the left side of the
needle.
6. Loosen the lower shaft crank arm screws (A).
7. While holding the shuttle hook so it doesn't turn, turn the handwheel toward you until the
needle comes to its lowest position.
Then, further turn the handwheel to raise the needle about 1.7 mm from its lowest position.
8. Tighten the screws (A).
9. Turn the handwheel toward you to check if the height is in the range of 1.45-1.95 mm.
If it is not in this range, repeat the above procedure.
10. Attach the shuttle race ring.
11. Attach the base.
Lower shaft crank arm
Screws (A) (2)
1.45–1.95 mm
Lowest position
Lower shaft

18
MODEL BL9
MECHANICAL ADJUSTMENT
BUTTONHOLE FEED BALANCE
To check:
When sewing buttonhole, the stitches on each side of buttonhole should be the same stitch
density.
The range of 9-12 stitches in the right side row "backward feeding" against 10 stitches in the
left side row "forward feeding" is considered acceptable.
Adjustment procedure:
1. Confirm the stitches by sewing buttonholes, and remove the cap.
2. Turn the adjusting screw in the direction of (C) in case of (A) (right stitches are rough), or in
the direction of (D) in case of (B) (left stitches are rough).
3. Mount the cap.
AB
Forward feeding Backward feeding Adjusting screw
(D) (C) Cap
Notch