Janome MyLock 434D Manual

The Janome MyLock 434D is a professional 4-thread overlock sewing machine designed for home and light commercial use. It features differential feed, adjustable stitch length and width, built-in rolled hemming, free arm capability, color-coded threading system, built-in thread tension dials, built-in needle threader, and safety stitch capability. Below are key sections for safety, features, setup, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation & Setup 3. First-Time Operation 4. Specifications 5. Controls and Settings 6. Threading Instructions 7. Stitch Selection 8. Maintenance & Cleaning 9. Safety Information 10. Troubleshooting

Features at a Glance

Key components: 4-thread overlock capability, Differential feed system, Free arm, Built-in rolled hem, Color-coded threading guides, Built-in needle threader.

Feature	Description
Differential Feed	Prevents fabric stretching or puckering
Stitch Length Dial	Adjustable from 1-4mm
Stitch Width Dial	Adjustable from 3.5-7mm
Built-in Rolled Hem	Easy conversion for fine edge finishing
Free Arm	For sewing sleeves and hard-to-reach areas
Color-coded Threading	Simplified threading process
Built-in Needle Threader	Easy needle threading
Presser Foot Pressure	Adjustable for different fabric types
Looper Thread Tension	Independent upper and lower looper tension
Needle Thread Tension	Independent needle thread tension

Installation & Setup

Unpack and inspect contents. Place on stable sewing table.

Remove machine from packaging: Carefully lift machine from box, remove all protective materials.
Install foot controller: Connect foot controller to machine port.
Connect power: Plug power cord into machine and electrical outlet.
Install accessories: Attach standard foot, thread stands, and other accessories.
Oil machine: Apply recommended sewing machine oil to designated points.

WARNING! Machine is heavy; lift with care to avoid injury. Ensure stable surface placement.

First-Time Operation

Power on machine; follow threading sequence.

Thread machine: Follow color-coded threading guides for upper looper, lower looper, and needles.
Select stitch: Choose appropriate stitch for your fabric type.
Adjust tension: Set thread tension according to fabric and stitch type.
Test stitch: Sew on fabric scrap to verify settings.
Adjust differential feed: Set according to fabric stretch requirements.

CAUTION! Keep fingers away from moving needles and cutting blade during operation.

Specifications

Type: 4-thread overlock sewing machine
Stitch Types: 4-thread overlock, 3-thread overlock, rolled hem, flatlocking
Stitch Length: 1-4mm adjustable
Stitch Width: 3.5-7mm adjustable
Differential Feed Ratio: 0.7-2.0
Speed: Up to 1300 stitches per minute
Needles: HAx1 SP system needles, size 11/80
Thread: Standard sewing thread, woolly nylon, decorative thread
Power Requirements: 110V, 60Hz
Weight: Approximately 15.4 lbs (7 kg)

Controls and Settings

Main controls located on front and side of machine.

Front Panel: Stitch length dial, Stitch width dial, Differential feed dial, Tension dials (4), Presser foot lever, Power switch.

Stitch Length: Adjust from 1mm (short) to 4mm (long). Stitch Width: Adjust from 3.5mm (narrow) to 7mm (wide). Differential Feed: Adjust from 0.7 (gathering) to 2.0 (stretching). Thread Tension: Four independent dials for upper looper, lower looper, left needle, right needle. Presser Foot Pressure: Adjustable for light to heavy fabrics.

Threading Instructions

Follow color-coded threading system for proper operation.

Upper Looper (Blue): Thread through blue guides and tension disc.
Lower Looper (Green): Thread through green guides and tension disc.
Left Needle (Red): Thread through red guides, tension disc, and use needle threader.
Right Needle (Yellow): Thread through yellow guides, tension disc, and use needle threader.
Verify threading: Ensure all threads are properly seated in tension discs and take-up levers.

Tip: Always thread with presser foot raised to release tension discs.

Stitch Selection

Supports multiple stitch types for various sewing applications.

4-thread overlock: For strong seams on woven and knit fabrics.
3-thread overlock: For lightweight fabrics and decorative edges.
Rolled hem: For fine edge finishing on delicate fabrics.
Flatlocking: For decorative seams and joining elastic.
Gathering: Use differential feed set above 1.0.
Lettuce edge: Use differential feed set above 1.5 on stretch fabrics.

WARNING! Always test stitch on fabric scrap before sewing project.

Maintenance & Cleaning

Unplug machine before maintenance. Regular cleaning ensures optimal performance.

Daily: Remove lint from looper area and feed dogs.
Weekly: Oil machine according to lubrication points diagram.
Monthly: Clean and oil cutting blade mechanism.
As needed: Replace needles after 8 hours of sewing.

CAUTION! Use only recommended sewing machine oil. Do not use household oils.

Safety Information

Always follow safety guidelines to prevent injury and machine damage.

Disconnect power when threading, changing needles, or cleaning.
Keep fingers away from cutting blade and moving parts.
Use proper lighting to see sewing area clearly.
Do not operate with damaged power cord or foot controller.
Keep machine away from children and pets when not in use.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Thread breaking	Incorrect tension/threading	Rethread machine; adjust tension; check for burrs on needle.
Uneven stitches	Differential feed setting	Adjust differential feed; check thread tension.
Fabric not feeding	Presser foot pressure	Increase presser foot pressure; clean feed dogs.
Loops on fabric	Looper timing/tension	Adjust looper tension; check looper timing.
Machine noisy	Lack of lubrication	Oil machine according to manual; remove lint buildup.
Needle breaking	Incorrect needle/bent needle	Replace with correct needle type; check for proper installation.

Service: Contact authorized Janome service center for technical issues.

Support: 1-800-631-0183; www.janome.com