Stitch - Bobbin Question

[Flattracker]

Hi, I'm having a bit of trouble with the machine stitches on my cylinder arm as you can see!

It starts off slow ok then the underside ends up looking like this or completely overloaded with thread. I'm stitching waxed cotton.

When I take the bobbin out, the thread has un ravelled itself inside the bobbin.

I've been trying to figure out what's causing it but not sure and don't want to start really messing about with adjustments and make things even worse if at all possible.

Any help would be great, if it's un ravelling does it mean the bobbin thread is too loose?

Thanks all.

[Flattracker]

Well not wanting it to beat me, I've been testing with a loud pink bobbin thread to see more what's happening.

This time using some calf leather, the first runs are furthest away.

You can hopefully see that the top thread is sitting up high! How do I adjust this?

The underside seems to be getting better, I backed off a little on the bobbin screw tension and also slackened off the big top adjusting screw for the walking foot.

I'm confused now though on the bobbin. Should it turn clockwise or anti-clockwise when looking at it with the cover off?

Thanks all.

[JLSleather]

That does look like no tension at all. This can be caused in any number of ways (or combinations of ways). Someone can likely help you, but it will be a big plus if you state the model of the machine you're using - and long as you're at it perhaps the thread and needle sizes.

[Flattracker]

Ah yes, it's a Wimsew W-246 Cylinder bed unison feed.

The black thread has a label IPCA Bond CB40 100% PA. I think that makes it equivalent to a US #69 size.

As for the needle, I don't know what size it is. It seemed to be stitching fine when I first got the machine but it's all going wrong at present! I did pick up a small box of Schmetz needles ranging in size 18 through to 22.

Thanks all

[BDAZ]

Try the Schmetz 18 or 19 and see if there is a difference. Make sure you are threading the machine properly. BAck off the upper tension completely and then add tension in 1/2 turn increments until the knot is centered in the material.

Hope that helps

Bob

(Former Surrey Resident)

[oltoot]

Clockwise for bobbin

[BDAZ]

On my machine the thread is wound COUNTER CLOCKWISE when inserted into the bobbin holder.

Cya!

Bob

[Flattracker]

Great! Progress!

I put the new #18 needle in, the one I took out is a Beka 130/21.

I did a test stitch run but still no real tension in the stitch.

So I turned the upper thread tension (spring) nut clockwise and did a test run and instantly I can now see on the top stitch that the pink bobbin thread has been pulled through so I can see little pink dots of thread. This is good right!? Or have I put too much tension on the top thread?

Do you think the 130/21 needle was too big for the size of thread (UK #40) US #69.

If the top stitch (needle thread) sits too high, is it adjusted by increasing the tension on the little bobbin screw?

Thanks all & Bob.

Richard

[Northmount]

Since you backed off the bottom tension compared to what it was (when it was sewing okay before), I would return it to where it was before. There needs to be some tension on the bottom. But an easy pull without any binding as you pull the thread. Then increase the top tension gradually in steps (if the knot is not being pulled up into the leather) while you are testing it. Make sure the top thread is between the tension disks.

The knot should be in the middle of the thickness of the leather. Generally, you should leave the bottom tension alone and adjust the top tension to move the knot into the middle of the leather. (Like all generalizations, when you make big changes to the material you are sewing, or sewing with, you may have to go back to the bobbin and adjust it.)

So if the knot is on the bottom of the leather, increase the top tension. If the knot is on the top, then decrease the top tension. If the thread seems loose, not pulled firmly against the leather and the knot is where it should be, then both tensions need to be increased.

For a needle/thread size chart take a look at http://www.tolindsewmach.com/thread-chart.html

There are lots of threads posted here about setting your tension. It would be worthwhile to do a search for them are see what others experiences have been and learn form them too.

Tom

[Flattracker]

Thanks man,

That's making a lot of sense.

It's late here so I'll get experimenting with tension tomorrow.

Big thanks

[Flattracker]

Just wanted to say thanks Tom. I've tamed the beast! At least for now!

It's working a treat now and more importantly now I understand what the threads are doing with your explanation, many thanks.