Harry Bloomfield wrote:
Cicero submitted this idea :
The spool carrier for the lower spool should show a curved steel spring
with a small slot and hole in it. The spool should go into the carrier so
that the thread unwinds to the left and is inserted through the slot in
the spring.

It was.


You might also have the thread tensioner set incorrectly. Look for two 1"
diameter dished disks held together by a spring - on the left hand side
above the needle. Check that the cotton can only be pulled through this with
some friction.

I had the tension set to minimum - 0, as when turned up to 5 it broke
the thread if pulled towards the needle.


Also check which side the thread goes through the eye of the needle - your
manual should tell you the correct entry for your machine.

I assumed it went through from front to back, but I will check that
point. Thanks...


Its been a long time since I played with an old swing bobbin thing,
but the basic idea is that the thread from the top is looped round the
bottom bobbin on each swing. Now IIRC those are fairly open
mechanisms, so you should be able to see what happens when you try to
sew with no cloth in place, and from that it should be possible to
deduce where the lower bobbin thread is in the wrong place.


NT