ELNA 320, 340 Service Manual

SERVICE MANUAL

MODEL: 320

CONTENTS

SERVICE ACCESS (1) FACE PLATE................................................................................................ 1

SERVICE ACCESS (2) BASE COVER.............................................................................................. 2

SERVICE ACCESS (3) FRONT COVER ........................................................................................... 3

SERVICE ACCESS (4) REAR COVER ............................................................................................. 4

MECHANICAL ADJUSTMENT .......................................................................................................... 5

ADJUSTING PRESSR FOOT HEIGHT AND ALIGNMENT............................................................... 6

ADJUSTING NEEDLE SWING..........................................................................................................7

ADJUSTING NEEDLE DROP POSITION ......................................................................................... 8

ADJUSTING NEEDLE TO HOOK TIMING ........................................................................................ 9

ADJUSTING NEEDLE BAR HEIGHT .............................................................................................. 10

ADJUSTING CLEARANECE BETWEEN NEEDLE AND HOOK POINT......................................... 11

ADJUSTING BACKLASH BETWEEN HOOK DRIVE GEAR AND LOWER SHAFT GEAR............ 12

ADJUSTING FEED DOG HEIGHT .................................................................................................. 13

ADJUSTING FEED BALANCE ........................................................................................................ 14

ADJUSTING BUTTONHOLE FEED BALANCE............................................................................... 15

ADJUSTING BUTTONHOLE ZERO FEED ..................................................................................... 16

MECHANICAL ADJUSTMENT ........................................................................................................ 17

REPLACING MOTOR AND ADJUSTING MOTOR BELT TENSION ............................................... 18

REPLACING AND ADJUSTING THREADER ................................................................................. 19

PARTSLIST................................................................................................................................ 20~41

1

Service Access (1)

FACE PLATE

<TO REMOVE>

Remove the cap and setscrew. Remove the face plate.

<TO ATTACH>

Attach the face plate with the setscrew. Attach the cap.

Setscrew

Face plate

Cap

2

Service Access (2)

BASE COVER

<TO REMOVE>

1 Loosen setscrews.

2. Take the base cover out.

<TO ATTACH>

3 Follow the above procedure in reverse.

Setscrew

Setscrew

Setscrew

Base cover

Setscrew

Setscrew

Setscrew

Feed dog drop le­ver

3

Service Access (3)

FRONT COVER

<TO REMOVE>

1 Remove the face cover and the base cover (see page 1, 2).
2 Remove dials (A), (B).
3 Loosen setscrews (A), (B), (C).
4 Unhook the tabs and remove the front cover.

<TO ATTACH>

5 Reverse the procedure above.

Dial (A)

Dial (B)

Tab

Setscrew(A)

(B)

Front cover

Tab

Setscrew (C)

Tab

4

Rear cover

(C)

(B)

(D)

Setscrew (A)

(B)

Presser lifter

(1)

(2)

(3)

Service access (4)

Rear cover

<TO REMOVE>

1 Remove the face cover and front cover (see page 1~3).

2 Remove setscrews (A), (B), (C) and (D).

Lower the presser foot.
Remove the rear cover from the part (1), (2) to (3) in order.

<TO ATTACH>

3 Mount the rear cover in reverse procedure of the removing.

5

Mechanical adjustment

TOP TENSION
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 Remove the face cover. (See page 4.)
2 Set the pattern selector dial at " ".
3 Open the shuttle cover.
4Remove 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 setscrews (A).
7 Adjust the height of the needle bar by moving the needle bar upward or downward
without turning it.
8 Tighten the setscrew (A).
9 Attach the shuttle race ring.

C

E

D

B

6

Presser foot lifter

Setscrew A

6 mm

Presser foot alignment

Presser foot should
be parallel to the feed
dog slots.

Adjusting Presser Foot Height and Alignment

The distance between the bottom of the presser foot in up position and the needle plate
should be 6.0 mm.

<TO ADJUST>

1 Remove the face plate (see page 1) and needle.
2 Lower the feed dog below the needle plate. Place a block 6 mm thick under the presser foot
and lower

the presser foot lifter.
3 Loosen the setscrew (A). Raise the presser foot lifter and tighten the setscrew (A) firmly.
4 Attach the needle and face plate.

NOTE:

Make sure that the presser foot should be parallel to the feed dog slots (B) in the needle plate.

Presser foot height

Presser foot

Needle plate

Feed dog

7

Adjusting Needle Swing

If the needle swing when it is still in the fabric, correct it as follows.

<TO ADJUST>

1 Remove the front cover (see page 3).

2 Select the zigzag stitch ( ) and set the stitch width dial at 5.

3 Loosen the setscrews on the worm.

4 While holding the worm as not to rotate, turn the handwheel to adjust the needle bar swing

so that the needle starts to swing 2 - 3 mm above the needle plate in the right outflow.
5 Tighten the setscrews on the worm securely.
6 Attach the front cover.

NOTE:

The upper shaft should turn smoothly without an excessive backlash between the worm
and gear.

Upper shaft

Setscrew

Worm

Needle plate

2 to 3mm

Backlash in­creases

Backlash
decreases

Note:

Make sure the worm does not
move sideways when turning the
handwheel, otherwise the
backlash will change.

8

Adjusting Needle Drop Position

The clearance between the needle and side edges of the needle hole should be 0.2
mm or more when the maximum width zigzag stitch ( ) is selecte. And the neddle
should drop in the center of the needle hole when the straight stitch is selected.

<TO ADJUST>

1 Remove the face plate (see page 1).
2 Select the straight stitch ( ) and set the stitch width dial at 5.
3 Loosen the setscrew.
4 Move the needle bar supporter so that the needle drops in the center of the needle hole.
5 Tighten the setscrew.
6 Select the zigzag stitch ( ) and set the stitch width dial at 5.0 to check the clearance

between needle and side edges of the needle hole.

7 Attach the face plate.

A

B

Setscrew

Needle hole

A=B

Needle bar supporter

9

Adjusting Needle to Hook Timing

The amount of ascending travel of the needle in the maximum width
zigzag stitch ( ) from the right lowest to where the hook point meets
the right side of the needle position should be 1.4 to 2.0 mm.

<TO ADJUST>

1 Select the maximum width zigzag stitch ( ) and set the stitch width dial at 5.
2 Remove the base cover (see page 2).
3 Remove the needle plate and bobbin holder.
4 Loosen the setscrews on the lower shaft gear.
5 Turn the handwheel toward you to bring the needle to the right lowest position. Then

raise the needle 1.7mm from the lowest position.
6 While holding the handwheel as not to move the needle bar, rotate the hook race until

the hook point meets the right side of the needle.
7 Tighten the setscrews.
8 Attach the bobbin holder and needle plate.
9 Attach the base cover.

NOTE:

Before performing this adjustment, be sure to check the needle bar height.

Needle plate

Bobbin holder

Lower shaft gear

Setscrews
(2 off)

1.4 - 2.0 mm

Lowest position
of the needle

Hook point meets the right
side of the needle.

Needle in right position

Setscrew

10

Adjusting Needle Bar Height

The standard distance between the upper edge of the needle eye and the upper surface
of the hook race should be in the range of 3.0 - 3.6 mm when the hook point meets the
right side of the needle in its ascending travel from the right lowest position of the
maximum width zigzag stitch ( ).

<TO ADJUST>

1 Select the zigzag stitch ( ) and set the stitch width dial at 5, then bring the needle to the

right lowest position.

2 Remove the face plate (see page 1).
3 Remove the needle plate and bobbin holder.
4 Turn the handwheel toward you until the hook point meets the right side of the needle.
5 Loosen the setscrew and move the needle bar up or down to adjust the needle bar height.

NOTE: Be careful not to rotate the needle bar.

6 Tighten the setscrew.
7 Attach the bobbin holder, needle plate and face plate.

NOTE:

Before performing this adjustment, check the needle to hook timing.

Setscrew

Needle

Alignment

3.0 - 3.6mm

Upper edge of
needle eye

Hook race unit

Needle plate

Bobbin holder

Upper surface of hook race

Setscrew

11

Adjusting Clearance between Needle and Hook Point

The standard clearance between the needle and hook point should be -0.10 to +0.05 mm.

<TO ADJUST>

1 Select the zigzag stitch ( ) and set the stitch dial at 5.
2 Remove the base cover (see page 2). Remove the needle plate and bobbin holder.
3 Replace the needle with the test pin. Loosen the setscrews (B) and (C). Slightly loosen

the setscrew (A).
4 Turn the handwheel toward you to bring the hook point behind the test pin.
5 Adjust the clearance to -0.1 to +0.05 mm by moving the hook base plate up or down.
6 Tighten the setscrews (A), (B) and (C) securely.
7 Check the backlash of the hook drive gear and lower shaft gear.

NOTE:
Adjust the backlash if necessary (see page 12).
8 Attach the base cover.
9 Replace the test pin with the needle. Attach the bobbin holder and needle plate.

Needle plate

Bobbin holder

Test pin

Hook point

Setscrew (A)

Setscrew (B)

Setscrew (C)

–0.1 to +0.05mm

Setscrew

Hook base palte

12

Adjusting Backlash between Hook Drive Gear

and Lower Shaft Gear

The rotary play should be 0.8 mm or less when the hook point is within the span of the feed
dog, and the
gears should turn smoothly.

<TO ADJUST>
1 Remove the base cover (see page 2).
2 Loosen the setscrews.
3 If the play is too big, turn the lower shaft bushing in the direction (B).

If the gear engagement is too tight, turn the lower shaft bushing in the direction (A).

4 Tighten the setscrews and attach the base cover.

NOTE:

Be sure to check and adjust the needle to hook timing and feed dog height if necessary, after
performing this adjustment.

A

B

A

B

Span of feed dog

Hook point

Check rotary play.

Lower shaft bushing

Hook drive gear

Lower shaft bushing

Lower shaft gear

13

Adjusting Feed Dog Height

The distance between the lowered presser foot and needle plate should be 0.75 to 0.85 mm
when the feed dog is in its highest position.

<TO ADJUST>
1 Select the straight stitch ( ) and set the stitch length dial at "4".
2 Lower the presser foot. Turn the handwheel to bring the feed dog to its highest position.
3 Remove the base cover (see page 2).
4 Loosen the setscrew (A) and nut.
5 Turn the adjusting screw to set the feed dog height to 0.8 mm.
6 Tighten the nut and setscrew (A).
7 Attach the base cover.

Presser foot

0.75 to 0.85mm

Needle plate

Feed dog

To raise

To lower

Adjusting screw

Nut

Setscrew (A)

14

Adjusting Feed Balance

The forward feeding (A) and backward feeding (B) should be equal when sewing stretch stitch
pattern.

<TO ADJUST>

1 Select the straight stretch stitch ( ) and set the stitch length dial at S.S.
2 Place a piece of paper under the foot. Turn the handwheel to check the needle marks.
3 If the forward feeding (A) is longer than backward feeding (B), turn the adjusting screw in the

direction (C).

4 If the forward feeding (A) is shorter than backward feeding (B), turn the adjusting screw in

the direction (D).

A

A

B

1

2

3

A

A

1

2

3

B

A

A

1

2

3B

A

B

A

B

A

B

(D) (C)

Adjusting screw

15

Adjusting Buttonhole Feed Balance

When sewing a buttonhole, the stitches on each side of the buttonhole should be the same
density.
The range of 9 to 12 stitches in the right side row against 10 stitches in the left side row is
considered acceptable.

<TO ADJUST>

1 Sew a test buttonhole and count the stitches on each side.
2 Remove the cap to access the adjusting screw.
3 If the left row is denser (A), turn the adjusting screw in the direction (C).
4 If the right row is denser (B), turn the adjusting screw in the direction (D).
5 Attach the cap.

AB

Cap

Adjusting screw

(C)

(D)

16

Adjusting Buttonhole Zero Feed

If the fabric is fed when sewing a bartack of the buttonhole, correct it as follows:

<TO ADJUST>

1 Sew a test buttonhole to check if the fabric is fed while sewing the bartacks.
2 Remove the cap to access the adjusting screw.
3 If the fabric is fed forward (A), turn the adjusting screw in the direction (C).

If the fabric is fed backward (B), turn the adjusting screw in the direction (D).

4 Attach the cap.

Bartack

Bartack

Cap

Adjusting screw

Adjusting screw

(B)

(A)

Stitch length dial

(D)

(C)

17

Mechanical Adjustment

TO CHECK:

If the material is feed forward or backward when sewing bartack on buttonhole, make an
adjustment as follows:

ADJUSTMENT PROCEDURE:

1. Set the pattern selector control at " " and the stitch length control at "4".

2. Remove the front cover. (See page 5.)

3. Place a piece of paper under the foot and turn the handwheel.

If the paper is fed forward, turn the adjusting screw in the direction of (C).

If the paper is fed backward, turn the adjusting screw in the direction of (D).

4. Attach the front cover.

FORW ARD FEEDING

BACKWARD FEEDING

(D) (C)

ADJUSTING SCREW

18

Replacing Motor and Adjusting Motor Belt Tension

<TO REPLACE THE MOTOR>
1 Remove the face plate, base cover, front cover and rear cover (see pages 1 to 4).
2 Remove the setscrews (A) and machine socket. Remove the setscrews (B) and machine

socket lid.

3 Remove the nuts and disconnect the motor cords.
4 Remove the setscrews (C) and motor.
5 To attach the motor, follow the above procedure in reverse.

<TO ADJUST THE MOTOR BELT TENSION>
1 Slightly loosen the setscrews (C).
2 While pushing the middle of the motor belt with a 300 grams load, move the motor up or

down so that the belt deflects 7 to 9 mm.

3 Tighten the setscrews (C) securely.

Setscrew (A)

Setscrew (B)

Setscrew (C)

Machine socket

Machine socket lid

7 to 9mm

300 grams load

240V

Setscrew (A)

Lamp cords

Motor cords

Nut

120V

Lamp cords

Motor cords

Nut

19

X

Replacing and Adjusting Threader

<TO REPLACE>

1 Remove the face plate (see page 1).
2 Pull the threader guard away from the threader.
3 Align the groove on the threader guide with the pin on the threader shaft and push the

threader guide up to snap it in place. (see Fig. 1).

<TO ADJUST>

1 If the hook (C) of the threader thrust or hit against the side edge of the needle eye,

loosen the setscrew (D) and adjust the lateral position of the threader plate (see Fig. 2).
2 If the hook (C) thrust against upper or lower edge of the needle eye, remove the face plate

and loosen the setscrew (F) and move the positioning base (G) up or down so that the hook

enters through the needle eye (see Fig. 3).

Hook(C)

Pin (B)

Threader guard (A)

(Fig. 3)

(Fig. 2)

(Fig. 1)

Setscrew(F)

Positioning base (G)

Threader plate (E)

View X

Setscrew (D)

Hook (C)

Hook (C)