Embroidery machine tension problems: how to fix them

How to read the back of your embroidery

Stitch a simple test such as a satin column letter I or H on two layers of medium cotton with stabiliser. Turn it over. With balanced embroidery tension, the bobbin thread forms a strip down the centre of the column, about a third of its width, with the upper colour visible on both sides.

If there is almost no bobbin thread on the back, the upper tension is too loose. If the back is almost all bobbin thread and it shows on the front, the upper tension is too tight or the bobbin tension too loose. Our tension balance explainer shows the same principle for normal sewing.

Symptom 1: bobbin thread showing on top

This is the most common complaint. Try these fixes in order and test after each one.

1. 1

   Check the bobbin is the right type for embroidery on your machine and inserted in the correct direction.

2. 2

   Make sure the bobbin thread is in the tension slot of the bobbin case.

3. 3

   Use a fine embroidery bobbin thread rather than normal sewing thread, unless the manual says otherwise.

4. 4

   Rethread the upper thread with the foot raised.

5. 5

   Fit a new embroidery needle, usually 75/11 for 40 weight thread.

6. 6

   If it persists, lower the upper tension one step at a time and test again.

Symptom 2: loops on the surface

Loose loops on the top of a design mean the upper thread is not under enough tension. Usually it has slipped out of the tension discs or the take-up lever. Raise the foot, rethread the entire path from the spool and check the thread is not caught on the spool cap or thread stand.

If loops appear underneath instead, building up into a tangle, that is bird nesting; see our embroidery machine bird nesting fix.

Symptom 3: thread shredding or breaking

Shredding is usually a needle problem. A worn or burred needle, a needle too small for the thread, or a needle inserted not quite fully up all cause shredding. Change the needle, try a 90/14 for metallic or thicker threads, and use a metallic or topstitch needle where recommended.

Old or poor quality thread also shreds, as does thread that twists off a spool too fast. Use a thread net on slippery spools, place spools as the manual recommends and reduce embroidery speed for metallics. Our machine embroidery thread explainer covers thread types and storage.

Note:Switch off before changing needles or removing the needle plate. Very frequent needle breaks can mean the hoop is not attached properly or the design is too dense; check both before continuing.

When to adjust the tension setting

Most computerised embroidery machines set upper tension automatically for embroidery, and some let you fine tune it on screen. Only change it once threading, needle and bobbin are right, and change it in small steps. Write down the default so you can return to it.

Bobbin case tension is set at the factory and should not normally need changing. Some machines have a separate embroidery bobbin case; check your manual before adjusting any screw. If a machine with correct threading and parts still stitches badly, have it checked by an engineer.

Prevent tension problems

Clean lint from the bobbin area after each large design, change the needle every few projects, use stabiliser suited to the fabric and hoop fabric drum tight. Read our embroidery stabiliser guide for stabiliser choices.

Machines with thread sensors and automatic tension make life easier for beginners. Compare models in our best embroidery machines for beginners guide.

See embroidery machines for beginners →

Frequently asked questions

Why does white bobbin thread show on my embroidery? Usually the upper tension is a little tight, the bobbin is the wrong type or the bobbin thread missed the tension slot. Check the bobbin first, then lower upper tension slightly.

What is the best tension setting for machine embroidery? There is no single number. Start with your machine's default for embroidery and adjust by reading the back of a satin column test.

Why does my embroidery thread keep shredding? A worn or wrong size needle is the most common cause. Fit a new embroidery needle and slow the machine for metallic thread.

Should I use the same thread in the bobbin as on top? For most designs, no. Use a fine embroidery bobbin thread, which keeps designs flat and reduces bulk.