klem kedidelhopper wrote:

On Jan 25, 3:41*am, (Adrian
Tuddenham) wrote:
wrote:
On Jan 23, 4:51*pm, klem kedidelhopper
wrote:
*[...]
... On my wife's
machine, the needle has just started to go back up when the pointy end
of the bobbin holder goes past and snags the thread that is sticking
out the side of the neeedle.

That is the critical point (no pun!): *As the needle starts to rise it
throws out a tiny loop of slack thread which the bobbin hook is supposed
to catch. *If the hook goes past before the needle has risen, the thread
will still be tight against the side of the needle and the hook will
miss it.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)www.poppyrecords.co.uk

I think I see what you guys are talking about. I can compare another
working machine I have here to this. It is also a Singer but slightly
different. The bobbin assembly mounts on end rather than lying flat
but it seems like catching the bobbin thread should still work the
same way. Thanks a bunch. Lenny

It is the upper thread which is caught and pulled around the bobbin, not
the bobbin thread.

The principle is common to most lockstich machines, sometimes the bobbin
case is in the form of a long shuttle, which plunges bodily through the
thread loop of the needle. Sometimes the bobbin stays still in the
centre of a ring; the ring rotates or oscillates and a notch in the
outer edge acts as a hook to catch the needle thread and pull it around
the bobbin holder.

As you say, the rotating or oscillating hook ring and the bobbin can be
in the vertical or the horizontal plane, but the timing is the same.
Some layouts are easier for the manufacturer to make, some are easier to
drive and others are easier for the operator to thread-up or clean.
(I'm sure some of the more bizarre arrangments are just a way of getting
around a patent.) A continously-rotating ring causes less vibration
than an oscillating one, so that tends to be used on higher-speed
machines.

Good luck with the repair.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk