Emblem edging machine — Merrow MG-3U

Industrial overedge machine for the dense thread-wrapped "Merrow edge" on emblems, badges and patches. One needle, two loopers, no bobbin.

Machine and table	Sewing area
Merrow MG-3U on its table	Fabric support plate and sewing area

Good to know

• Handwheel direction: top away from you (clockwise from the wheel side).

• Oil: automatic recirculating system — keep the reservoir above E.

• Border width and stitch density are set by installed parts (feed eccentric, plate, foot) — not operator settings.

• Several cones feed the upper looper together (diagrams 78/78S) — it's not one cone per thread path.

• Keep a good border sample with the machine for comparison.

Safety

• Needle guard always fitted.

• Power off for threading, needle changes and adjustments; unplug for cleaning.

• Fingers clear of needle, loopers, cutters, belt and pulley.

• Turn the handwheel only top-away.

• Stop on binding, metal contact or jams — never force it.

Drive

VEVOR 750 W brushless servo, 220 V 50 Hz, pedal-controlled, belt drive. Motor speed 500–3,500 rpm (the head speed depends on the pulleys). Get the speed and pedal response demonstrated; keep the rotation direction as set.

Nameplate	Motor and drive
MG-3U nameplate, serial 213269, oil window	Servo motor, belt and linkage under the table

Needle and threading

• Needle (p. 10): loosen the nut just enough, insert fully against the internal stop, tighten. Don't remove the nut. Turn by hand to check clearance.

• Thread: cones upright, guides aligned above them. Follow every guide in diagram 78 or 78S (matching the installed plates).

• Tested combination: embroidery thread for needle and lower looper, Merrow thread for the upper looper.

• Loopers (p. 16, threading wire 37-318):

  1. Needle at its highest; lower-looper eye aligned with its tube. Wire through tube and eye; tail above the plate.

  2. Upper looper: bend the wire, pass through the tube in the dust shield, thread the eye.

  3. Upper thread must run straight from the tube to the eye — not wrapped round the looper.

• Lightest tension that forms a sound border; change one at a time.

How to use

1. Power off: check needle, threading, needle guard, oil above E. Clear the pedal.

2. Turn the wheel one full cycle (top away). Stop if anything touches or binds.

3. Scrap patch under the foot, foot down, start slowly.

4. Guide the edge into the border; let the feed move it. Practise curves and corners.

5. Check both sides for even coverage.

6. Finish with the demonstrated overlap; stop before removing, leave tails.

7. Switch off, brush lint, return tools.

Troubleshooting

Maintenance

• Oil: reservoir above E; MG spindle oil 46 cSt at 40 °C (p. 29). Don't overfill. If no oil flows in the bubbler, stop — running dry seizes the machine (pp. 8–9).

• Daily when used: clean lint from the drain slots around the lower-cutter support. No compressed air inside (p. 8).

• Brush lint from the feed area, behind the dust shield and round the fabric guard.

• Oil filter: clean yearly, replace after four cleanings (maintainer).

• Cutters, feed eccentric, timing: maintainers only.

• Maintenance and repairs log

Specifications

Documents and links

• Merrow Class MG / M instruction book (PDF) — page numbers above.

• Merrow Class MG / M parts book (PDF)

• MG-3U threading: diagram 78 (PDF) · diagram 78S (PDF)

• VEVOR four-button controller manual (PDF) — related model; settings up to 5,000 rpm don't apply.

• VEVOR servo product page

• Merrow: MG-3U · support and parts · threading · needles · oil troubleshooting

• Sewing machines · Open questions