The Janome 634D Mylock is a professional-grade 3/4 thread serger with differential feed, built-in rolled hem capability, color-coded threading system, easy tension dials, free arm capability, and built-in thread cutter. It features adjustable stitch length (1-4mm) and width (3-7mm), maximum speed of 1300 stitches per minute, and includes accessories like tweezers, screwdrivers, and lint brush. Below are key sections for safety, features, setup, operation, maintenance, and troubleshooting.
Key components: Color-coded threading system, Differential feed mechanism, Free arm, Built-in rolled hem, Stitch length/width controls, Built-in thread cutter.
| Feature | Description |
|---|---|
| Differential Feed | Prevents fabric stretching or puckering |
| Rolled Hem | Creates narrow, professional hems |
| Color-coded Threading | Simplifies threading process |
| Free Arm | For sewing cuffs and tubular items |
| Stitch Length Control | Adjustable from 1-4mm |
| Stitch Width Control | Adjustable from 3-7mm |
| Built-in Thread Cutter | Convenient thread trimming |
| Tension Dials | Easy adjustment for perfect stitches |
| LED Light | Illuminates work area |
| Accessory Storage | Built-in compartment for tools |
Unpack and inspect all contents. Place on stable surface.
WARNING! Machine is heavy; lift with care. Ensure stable work surface before operation.
Power on machine; follow threading sequence.
CAUTION! Keep fingers away from moving needles. Always use foot control.
Main controls: Power switch, Stitch length dial, Stitch width dial, Differential feed dial, Tension dials (4), Rolled hem lever.
Adjustment Points: Upper looper tension, Lower looper tension, Needle thread tensions, Presser foot pressure, Knife position.
Stitch Selection: 3-thread overlook (narrow/wide), 4-thread safety stitch, Rolled hem (2-thread/3-thread). Differential Feed: Adjust for different fabric types (stretchy to non-stretchy).
Follow color-coded threading path for each thread.
Tip: Always thread with presser foot raised to open tension discs.
Supports multiple stitch types for various applications.
WARNING! Always test stitch on fabric scrap before sewing project.
Regular maintenance ensures optimal performance.
CAUTION! Unplug machine before cleaning or maintenance.
Standard accessories included with machine.
| Accessory | Purpose |
|---|---|
| Tweezers | Threading assistance |
| Screwdrivers | Adjustments and maintenance |
| Lint Brush | Cleaning loopers and feed dogs |
| Oil Bottle | Machine lubrication |
| Spare Needles | Replacement needles |
| Spool Caps | Thread spool management |
Janome 634D Mylock comes with limited warranty covering manufacturing defects. Warranty period: 25 years for mechanical parts, 2 years for electronic components, 1 year for labor. Registration required within 30 days of purchase. For warranty service, contact authorized Janome dealer with proof of purchase.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Thread breaking | Incorrect tension/threading | Re-thread following color codes; adjust tension |
| Uneven stitches | Differential feed setting | Adjust differential feed ratio; check fabric type |
| Fabric puckering | Tension too tight | Loosen tension dials; test on scrap fabric |
| Loops on fabric | Looper timing | Check looper threading; adjust looper tension |
| Machine jams | Thread buildup | Clean loopers and feed dogs; re-thread properly |
Service: Contact authorized Janome service center for technical issues.
Support: 1-800-631-0183; www.janome.com