What do you do when thread keeps breaking?
When the thread on a commercial embroidery machine keeps breaking, it’s a frustrating but common problem. The key is to approach it methodically, as there are many potential causes. Here is a step-by-step troubleshooting guide:
Step 1: Check the Basics
Re-thread the Machine: This is the most frequent cause of thread breaks. A missed tension disc, a tangled thread at the cone, or improper placement in a thread guide can all cause issues. Re-thread the entire upper thread path, from the cone to the needle.
Check the Needle: A bent, dull, or burred needle is a primary culprit. Replace the needle with a new, high-quality one of the correct size and type for your fabric. Ensure it’s inserted correctly with the scarf facing the right direction (consult your manual).
Check the Bobbin: Make sure the bobbin is wound evenly and correctly, with no over-winding or tangles. The bobbin case should be clean, with no lint or nicks. Ensure the bobbin is inserted correctly into the bobbin case.
Step 2: Address Tension Issues
Upper Thread Tension: If the top tension is too tight, it puts too much stress on the thread, causing it to snap. Loosen the upper tension slightly. You can test the tension on a piece of scrap fabric—the back of the design should show about one-third bobbin thread and two-thirds top thread.
Bobbin Tension: If the bobbin tension is too loose, it can create a bird’s nest on the back of the fabric, which can cause the top thread to break. If it’s too tight, it will pull the top thread down too hard. To check, hold the bobbin case by its thread and give it a slight bounce. It should unwind about an inch. If it unwinds too much, tighten the tension screw; if it doesn’t move, loosen it.
Hooping: Improper hooping can lead to tension issues. Make sure the fabric is taut like a drum and secured to the stabilizer, without stretching or distorting it. The hooping frame should be firm in the machine’s arm.
Step 3: Inspect the Thread and Fabric
Thread Quality: Low-quality thread can be a major source of problems. It may not be lubricated properly, or it may have slubs and inconsistencies. Invest in high-quality commercial-grade thread.
Thread Type and Size: Ensure the thread is the correct weight and type for your needle size and machine. For example, thicker threads require larger needles.
Fabric and Stabilizer: The stabilizer is a critical part of the equation. If it’s too light for the fabric and design, the fabric can move and cause thread breaks. Make sure you are using an appropriate cut-away, tear-away, or water-soluble stabilizer.
Step 4: Check for Machine and Environmental Issues
Lint and Debris: A build-up of lint and thread scraps in the thread path, needle plate, or bobbin case can snag the thread. Clean the entire machine thoroughly, especially the tension discs, thread guides, and the area around the rotary hook.
Burrs and Nicks: Inspect the thread guides, needle plate hole, and rotary hook for any small burrs or nicks. Even a tiny imperfection can fray and break the thread. Use a magnifying glass if needed. If you find one, it may need to be buffed out or the part may need to be replaced.
Machine Speed: Running the machine at too high a speed for the design can cause excessive friction and stress on the thread. Slow the machine down, especially on dense designs or with delicate thread.
Moisture and Temperature: High humidity can cause some threads to become sticky, while very dry conditions can make them brittle. Store your thread in a climate-controlled environment.
Summary Troubleshooting Checklist
Re-thread the machine completely.
Replace the needle.
Clean the bobbin case and rotary hook.
Adjust the upper and bobbin tension.
Check for proper hooping.
Switch to a different thread cone or brand.
Slow down the machine speed.
Clean the entire machine, especially the thread path.
Inspect for any nicks or burrs on machine parts.
If you have gone through all these steps and the thread is still breaking, it may be a sign of an internal timing issue or a more serious mechanical problem that requires the attention of a professional embroidery machine technician.