Most machines have a specific thread path for bobbin winding that's separate from the normal sewing path. If the thread isn't routed correctly, the bobbin won't wind properly.

• Make sure the thread is coming off the spool smoothly and is routed through the bobbin winding thread guide
• Check your manual if you're unsure of the correct winding path for your machine - it's easy to miss a guide

As the thread winds, it should pass through or around a small tension disc. This controls how tightly the thread winds onto the bobbin — if the thread bypasses it, the bobbin will wind loosely and cause tension problems when sewing.

• Check the thread is correctly seated in the bobbin winding tension disc before winding
• Refer to your manual to confirm where the disc is on your machine if you can't locate it

If the bobbin isn't fully engaged on the winding pin, it will spin without picking up the thread properly.

• Push the bobbin firmly onto the bobbin winding pin
• Slide or click it into the winding position — most machines require the pin to be pushed to one side to engage the winding mechanism
• The machine shouldn't sew while the bobbin winder is engaged - if it does, the bobbin isn't in the correct position

Starting the wind correctly makes a big difference to how evenly the bobbin fills.

• Pass the thread through the small hole in the top of the bobbin from the inside out
• Hold the thread tail as you begin winding - this anchors it and starts a clean, even wind
• After a few wraps you can let go of the tail and allow the machine to wind on its own

Winding too fast can result in an uneven or loosely wound bobbin.

• Wind at a moderate, steady speed rather than full speed
• The thread should layer evenly from side to side as it fills — if it's piling up in one spot, stop and recheck the thread path

Using the wrong bobbin or a damaged one is a surprisingly common cause of winding problems.

• Make sure you're using the correct bobbin for your specific machine - bobbins are not universal and the wrong type won't wind or sit correctly
• Inspect the bobbin for any cracks, chips or warping and replace it if you find any damage

If the bobbin spins freely but thread won't wind onto it, the small rubber ring on the bobbin winder spindle is likely worn. This ring creates the friction needed to drive the bobbin round — when it wears down it can't grip properly.

• Inspect the rubber ring on the bobbin winder for signs of wear, flattening or cracking
• Replacement rings are inexpensive and widely available - this is a common wear part
• If you're not sure how to replace it, get in touch and we can advise