Detailed Elna 624DSE, 614DE, 604E, 644 and 634 Overlock Sewing Machine Technical Reference - Instruction Manual & Maintenance Guide 1998

elna 600 Series Operators Manual - 1998 Edition

This technical documentation provides the foundational operational and maintenance protocols for the elna 600 series overlock machines, ensuring high-fidelity stitching and mechanical longevity. A critical maintenance requirement involves locking the moving blade with an Allen screwdriver through a specific needle plate hole when processing extra heavy fabrics; failure to properly manage this setting can lead to blade deflection or needle breakage during high-torque operations.

Machine Architecture & Series Applicability

Updated 600 Series Generations

• Model 644: Successor to Model 624 (featuring the advanced tilt-up needle clamp).
• Model 634: Successor to Model 614.

Technical Series Designations

• Model 624DSE: Features include a safety device, tension release lever, 2-thread converter, and waste tray.
• Model 614DE: Standard differential feed and cutting width adjustments.
• Model 604E: Entry-tier 600 series technical configuration.

Operational Advantages & Accuracy

• Precision Stitching Control: Integrated differential feed slides (Models 624/614) prevent puckering on extensible knits and waving on lightweight sheers.
• Enhanced Safety Protocols: Machine operation is automatically inhibited when the front door is open (Model 624), mitigating the risk of injury from moving internal components.
• Tool-Less Conversions: The instant rolled/narrow hem device allows for rapid transition between stitch types without requiring needle plate or presser foot hardware changes.

Document Metadata

• Print Number: 396162-02 (Part No. 11517)
• Total Pages: 31 Pages
• Publication Date: December 1998 (Revision of November 1994)

Factory Benchmarks & Calibration Data

Stitch formation is governed by precise tension settings and mechanical alignments. Balanced tension requires needle threads to lie on the top side of the fabric while locking with the lower looper thread exactly on the fabric edge. Needle systems are restricted to ELx705 or 130/705H (15x1) variants to maintain timing synchronization with the upper and lower loopers.

Diagnostic Schematics & Maintenance Visualization

Technical illustrations provide exploded views of the front door assembly, side cover internals, and threading routes. Color-coded paths (Blue, Red, Yellow, Green) designate the exact sequence for upper looper, lower looper, and dual-needle threading, which is essential for preventing skipped stitches and thread breakage.

Table of Contents

• Preparation: Thread Guide Pole, Cone Holders, and Extension Discs
• Threading: Upper/Lower Looper and Needle Threading Sequences
• Adjustments: Thread Tensions, Stitch Length, and Differential Feed
• Utility Stitches: 3/4-Thread Overlock, Rolled Hem, and Flatlock
• Operational Applications: Turning Corners and Curved Edges
• Maintenance: Cleaning, Lubrication, and Blade Replacement
• Troubleshooting: Minor Disorders and Mechanical Corrections

Operational Limits & Specifications

• Maximum Lamp Input: 15 Watts.
• Moving Blade Clearance: 0.5 mm to 1.0 mm below the fixed blade surface upon replacement.
• Stitch Length Range: 0.5 mm to 4.0 mm.
• Differential Feed Ratio: 0.5 (for sheers) to 2.0 (for stretch knits).
• Lubrication Requirement: Specific high-speed sewing machine oil applied to the needle bar and looper drive points after periods of storage or heavy utilization.

FAQ

Does this manual provide the correct specifications for both the Elna 634 and 644 series machines? Yes, this documentation explicitly defines the 600 series update, instructing users to substitute model numbers 634 for 614 and 644 for 624. It covers these models along with the 624DSE, 614DE, and 604E variants, ensuring all technical data and operational instructions are applicable to these updated generations.

What is the specific factory calibration required for the moving blade after replacement? When installing a new moving blade, the manual specifies a critical clearance setting. The edge of the new moving blade must be positioned approximately 0.5 mm to 1.0 mm below the surface of the fixed blade. This precise alignment is necessary to maintain clean cutting performance and prevent mechanical jamming.

How does the manual describe the system for preventing fabric puckering on stretch materials? The manual details a specialized Differential Feed system equipped with two independent feed dogs. By adjusting the differential feed control slide to a higher number (up to 2.0), the front feed dog moves the fabric faster than the rear dog. This specific mechanical action prevents knitted or stretch fabrics from puckering or waving during high-speed sewing.

What specialized procedure is required for sewing extra heavy fabrics? To handle high-torque demands and prevent needle breakage, the manual instructs users to lock the moving blade. This is achieved by inserting a 1.5mm Allen screwdriver through the specific needle plate hole marked "e" to tighten screw "c." Once the heavy-duty task is complete, the screw must be loosened slightly to unlock the blade for normal operation.

Can I find specific technical navigation aids like color-coded threading diagrams in this digital version? Yes, the manual contains high-utility threading schematics that use a specific four-color system: Blue for the left needle, Red for the right needle, Yellow for the upper looper, and Green for the lower looper. These diagrams are essential for troubleshooting skipped stitches and can be easily searched or printed for use at the workstation.