Electric Sewing Machine Repair Manual

 

1. Needle breaks when electric sewing machines sew thick material

- Analysis: Needle too thin or bent, uneven fabric thickness, excessive needle bar movement

- Solution: Use a thicker new needle, sew slower, and assist feeding manually, replace needle bar or bushing

 

2. Frequent breaks with short stitches, but not with long stitches

- Analysis: Delayed feed dog action, defective feed dogs, needle hitting rear of feed dogs

- Solution: Adjust feed cam timing, shorten stitch length, replace feed dogs

 

3. Needle breaks below needle plate

- Analysis: Needle too low, hitting the shuttle. The shuttle was not installed properly, shuttle point hit the needle. Excessive or insufficient clearance between shuttle carrier and needle. The carrier not guarding the needle.

- Solution: Adjust needle bar/needle position, reinstall shuttle, and adjust carrier clearance to the needle.

 

4. Needle breaks above needle plate

- Analysis: Excessive fabric pulling, bending needle. Loose presser foot screw, foot hitting needle. Feed cam causes the fabric to pull and break a needle. Hard object in fabric.

- Solution: Practice operation, tighten foot screw, adjust feed cam.

 

 

1. Identify cause

- Check needle condition (bent, blunt, installed correctly)

- Check threading, especially around the thread guide

- Check thread quality, consider lubricating with silicone

 

2. If the above is eliminated, check the needle and looper relationship

- Check timing - when the needle bar reaches the lowest point and just starts rising, the thread loop should start forming on the right needle. Standard timing - when the looper moves left, its tip should be 0.5-1mm above the left needle eye.

- Check clearance - right needle should have 0-0.05mm clearance to looper, left needle -0.03-0.1mm. This creates a 2-5 degree slant. When the looper starts moving right from the left dead center, its eye should be 1.5-2.5mm from the left needle. The left needle should pass through the looper with 0-0.05mm clearance.

- Check the relationship between needles and front/rear needle guards. Excessive clearance in front can cause unstable loop formation and delayed timing. Improper guard height can also cause issues. The front guard should have -0.01-0mm clearance to the needle, and be 1mm above the left needle tip when the looper passes. Adjust the rear guard for proper loop clearance without interfering with the looper. Refer to manual diagrams.

- Skipped stitches at beginning of seam - fabric thickness pushes needles back so looper passes in front. Adjust the rear guard closer to the needle backs, just touching is fine. Reduce front clearance slightly. Needles should move smoothly without breaks or jams.

- Skips from take-up lever cam - check looper thread tension and timing. Early take-up will cause issues. Cam should be adjusted so the triangle loop has proper tension when the left needle passes through.

 

 

 

1. Top and bobbin threading must be correct per the diagram. A machine won't work otherwise.

2. Needle must be threaded correctly (front to back).

3. Don't use the foot pedal and power button together.

4. Remove batteries when using the transformer.

 

 

1. The power button and foot pedal cannot be used together.

2. The rectifier and batteries cannot be used together, which will damage the machine.

3. Wrong battery polarity will reverse the machine, and prevent sewing.

4. Prolonged reverse operation damages the machine.

5. Excessively hard or thick fabrics cannot be used.

6. Use 6V 1.0A rectifier or 4 AA batteries.

 

 

1. High efficiency and specialization - modern speed can exceed 5000rpm, auto-oiling. Many specialized machines like auto-oilers, sergers, and automatic bag openers.

2. Durable and stable performance, fewer issues inconsistent production.

3. Increasing automation, simpler operation - short training for proficiency.

 

 

1. General purpose - most common, wide application in garment production. E.g. cover stitch machines, chainstitch machines, flatbed machines, stretch stitch machines.

2. Special purpose - specific processes like buttonholers, eyelet machines, and overlock machines.

3. Decorative - decorative stitches like embroiderers, and zigzag machines.

 

 

I. Cleaning

1. Read the manual thoroughly, focusing on the shuttle area.

2. Unplug power.

3. Dismantle and remove the shuttle per manual.

4. Clean the shuttle thoroughly with a soft brush and cloth.

5. Reinstall the shuttle.

6. Wipe down the machine body with a clean, slightly damp cloth.

7. Test run to ensure correct reassembly.

 

II. Oiling

- Reduces friction and noise.

- Follow the recommended oiling schedule per machine model.

- Oil ports provided, don't miss any.

- Just 1-2 drops per spot, don't overoil.

 

If you need to purchase Electric Sewing Machines, please contact us at sale@eagleco.cn.