Skip to content
When an embroidery machine starts sewing after a trim, the upper thread should remain secure long enough for the first stitches to lock with the bobbin thread. If it repeatedly pulls out of the needle instead, the problem is usually somewhere within the trimming, tension or start-up sequence.
The good news is that most thread pull-outs can be diagnosed systematically.
In this guide, ETC's embroidery specialists explain what is happening inside the machine, which components to inspect and the order in which to check them.
What causes thread to pull out?
Thread pull-outs usually occur because the machine is not leaving or holding enough upper thread after a trim.
Several factors can contribute:
• Incorrect upper or bobbin tension
• A bent or incorrectly positioned picker
• Backtack being switched off
• Insufficient inching stitches after a trim
• Incorrect picker release timing
• A sticking or faulty picker mechanism
• Start with the simplest checks before changing machine parameters.
1. Check the thread tension
Begin by inspecting the reverse of a recently embroidered design.
A balanced stitch should show the bobbin thread running consistently through the centre, with the upper thread visible on either side. If very little bobbin thread is visible, the bobbin tension may be too tight or the upper tension may be too loose.
Perform a bobbin drop test
Remove the bobbin case and hold it by the thread. With a gentle movement, the case should drop approximately 25-40 mm.
If it does not move, the bobbin tension may be too tight. If it falls freely, it may be too loose.
Once the bobbin tension is correct, adjust the upper tension if necessary. When working with a two-part upper tension assembly, turn the small and large tension controls together so that the balance between them is maintained.
Expert tip: Change one variable at a time and sew a short test after every adjustment. This makes it much easier to identify the actual cause.
2. Inspect the picker
The picker is the fork-shaped component beside the bobbin area. After a trim, it helps position the bobbin thread so that the next stitches can form correctly.
Push the picker fully into position and use the support bracket above it as a visual reference. The picker arm should appear straight and should move without catching.
Check that:
• The arm is not bent or twisted
• It does not touch the screw or surrounding bracket
• The bobbin pigtail sits centrally between the picker's two prongs
• The picker moves freely through its full range
If the arm is touching another component, loosen its retaining screws and adjust its position carefully before retightening.
Avoid forcing the picker. If it is badly bent, damaged or difficult to move, speak to a technician before making further adjustments.
3. Confirm that automatic backtack is enabled
Backtack adds reinforcing stitches at the beginning of a section and immediately after a trim. These stitches help secure the thread before the machine returns to normal sewing speed.
Locate the embroidery parameters on your machine and check that Auto Backtack is set to All.
Menu names differ between machine models, but the setting is normally found under:
Settings - Embroidery Parameters - Auto Backtack
If your control panel uses a text-only display, look under the machine's embroidery function menu.
4. Review the inching settings
Inching stitches are the slower stitches sewn when the machine starts or resumes after a trim. They give the upper and bobbin threads time to connect securely.
If too few inching stitches are used, the upper thread may escape from the needle before the stitch has locked.
For compatible machines, useful starting values are:
• After Trim Inching Stitch: 4
• Inching Stitch: 3
• Picker Off Timing: 40
Treat these figures as diagnostic starting points rather than universal settings. Machine models and control systems vary, so check the manufacturer's instructions before changing parameters.
Increasing the picker-off timing generally leaves a longer thread tail, which can improve the connection after trimming. If the tail becomes excessively long or begins dragging across the garment, reduce the value gradually.
5. Test the picker operation
Most industrial embroidery machines include a diagnostic test for the picker.
Open the machine-test menu, select the picker test and run it several times while observing the mechanism. It should activate smoothly and return to the same position on every cycle.
Look for:
• Hesitation or sticking
• Incomplete movement
• Contact with another component
• Failure to activate
• Inconsistent positioning
If the picker does not operate at all, the solenoid or its electrical connection may require professional attention.
A practical diagnostic order
When thread repeatedly pulls out after trimming, work through the machine in this order:
1. Inspect the stitch balance.
2. Test the bobbin tension.
3. Check the upper tension.
4. Inspect the picker's position and movement.
5. Confirm that Auto Backtack is enabled.
6. Review the inching and picker-timing settings.
7. Run the picker diagnostic test.
This sequence helps you eliminate the most common causes without making unnecessary adjustments.
When to ask an expert
Stop and seek technical advice if the picker is damaged, the solenoid does not activate or the problem continues after the tension and parameter checks.
When contacting ETC, tell us:
• Your machine make and model
• Whether the problem occurs on every needle
• Whether it happens only after a trim
• Which thread and needle you are using
• Any settings you have already changed
Photographs of the stitch reverse and a short video of the trimming sequence can also help our specialists identify the cause more quickly.
Learn from ETC's embroidery specialists
ETC Supplies has supported embroidery businesses for more than 30 years. Our Help Centre brings that practical experience together in clear guides designed to help you understand your equipment, improve production and solve problems with confidence.
Products related to this guide
Troubleshooting a thread pull-out may involve checking or replacing several embroidery essentials:
• Shop polyester embroidery threads
• Shop bobbins and underthreads
• Shop embroidery needles
• Shop embroidery machine parts
Need help diagnosing a persistent thread pull-out? Contact our embroidery specialists for practical advice.