Why won’t my bobbin winder work?

Two causes cover the great majority: the spindle is not engaged properly, or the rubber drive tyre has hardened.

Check the spindle first. It has to be pushed firmly across until it clicks into the winding position. Half-engaged, the machine either does nothing or runs the needle instead. On most machines the needle bar stops moving when the winder is engaged — if the needle is still going up and down, the winder is not across.

Then the drive tyre. The winder is driven by a small rubber wheel pressed against the handwheel rim. Rubber perishes: it glazes, shrinks or goes shiny, and then it slips. Symptom is a winder that turns slowly or stops as soon as thread builds up. The tyre is a cheap replacement part on most machines and a straightforward swap.

Then the thread path. The thread must run through the bobbin winder tension guide, not straight from the spool. Without it the bobbin winds loose and slips, which feels like a winder fault.

Then the bobbin itself. A bobbin of the wrong class sits too loosely on the spindle and spins without filling. Check the class in your manual, and check the bobbin is pushed down fully with the thread tail brought up through the small hole where the design calls for it.

Then the stop lever. Many winders have an adjustable stop that halts winding at a set fullness. If it has drifted, it can stop the bobbin almost immediately.

A motor fault is last and is uncommon.