Tension Problems With Seiko Sth-8Bld-3

[KelseyR89]

I just bought my first machine and am having a horrific time trying to get the tension right. My machine is a Seiko STH-8BLD-3 and there is shockingly little information online and hardly any YouTube videos for it, so I'm kind of out of luck! I basically just cannot get the stinkin' tension right, no matter what I do. I can get it to a certain point, but regardless of if I tighten just the top, or just the bobbing, or a combination of both it doesn't matter - the little loop/knot on the back side never improves past a certain point.

I initially adjusted the bobbin tension to the tightness they recommended - tight enough so when you hold the thread the bobbin doesn't fall. I left the top tension alone so it was loose, then when I realized that wasn't going to work I tried JUST tightening the top tension, three little notches at a time, and it would improve but only to a certain point. I did that until the top tension was quite tight, when that didn't work I loosened the top tension all the way and tried tightening the bobbin, then repeated slowly increasing the top tension. That only got me to a certain point as well, so this time I loosened the bobbin to recommended tightness and then REALLY tightened the top tension, still no improvement past a certain point. It's ALWAYS the bottom stitch that isn't correct. I can reduce the size/looseness of the knot/loop on the bottom stitch, but no matter what I do it only gets better to a certain point and then nothing I do improves it any more! So frustrating.

I attached some pictures because in all the other posts I've read about tension that seems to be helpful. The first 2 pictures are of stitching on dyed leather I took the store that sold me the machine so I know what it could/should look like! And the weird thing is the front stitch when I sew it isn't near as straight as when it was at the store! Does that have to do with the tension as well?

Thanks in advance for any advice, I would love to get this machine all figured out so I can start working on larger products!!

[Northmount]

If the needle is too small, the top tension can't pull the knot up in thick hard leather. Try a larger needle versus your thread size. Also try lubricated thread.

Tom

[Ferg]

Change your routing of the thread after the post on top of machine. From right to left through the top hole, left to right in middle hole,(don't wrap thread around this),the right to left through the bottom hole.

I don't know how you have your thread coming off this three hole piece for sure, this is the way it should be. From the bottom of the three holes go over the top of the adjusting discs, pull the thread between the discs and out the right side of same then down under the bottom adjuster, between the discs up on left side. When you pull the thread up to go into the top "Uptake" make sure the thread hooks over the little pointed piece on the back disc.

The remainder of your thread route looks okay.

After doing this do not change any tension before trying to sew. If the thread is still pulled out to the bottom you need to loosen the tension screw on the bobbin. One/eighth of a turn each time before testing again. If you need to do this more than 3 or 4 times you have your top tension messed up or the wrong "Bee Hive" spring on your top adjuster.

ferg

Edited August 21, 2015 by 50 years leather

[KelseyR89]

If the needle is too small, the top tension can't pull the knot up in thick hard leather. Try a larger needle versus your thread size. Also try lubricated thread.

Tom

I was wondering if that maybe was the problem. The needle(s) it came with are the ones that the store gave me, so I'm assuming they're the correct size but that might be worth checking out. Thanks!

[Northmount]

See this chart http://www.tolindsewmach.com/thread-chart.html

Tom

[KelseyR89]

Change your routing of the thread after the post on top of machine. From right to left through the top hole, left to right in middle hole,(don't wrap thread around this),the right to left through the bottom hole.

I don't know how you have your thread coming off this three hole piece for sure, this is the way it should be. From the bottom of the three holes go over the top of the adjusting discs, pull the thread between the discs and out the right side of same then down under the bottom adjuster, between the discs up on left side. When you pull the thread up to go into the top "Uptake" make sure the thread hooks over the little pointed piece on the back disc.

The remainder of your thread route looks okay.

After doing this do not change any tension before trying to sew. If the thread is still pulled out to the bottom you need to loosen the tension screw on the bobbin. One/eighth of a turn each time before testing again. If you need to do this more than 3 or 4 times you have your top tension messed up or the wrong "Bee Hive" spring on your top adjuster.

ferg

Hi Ferg!

Thanks for the input. I went ahead and threaded it like you suggested, but it almost seemed like the top tension was too tight. After I was done sewing I had to pull extremely hard to get the thread to come out enough where I could cut the 2 threads, so hard I was worried I might break the needle! I kept it how you suggested though and played around with the bobbin tension, and then the top tension just because I'm so flabbergasted as to what is going on, and nothing seemed to change any way I tried it :/ Something has to be wrong with the machine, I swear! I've spent so many hours trying to get that dang tension figured out and once I get the lower stitch to a certain point nothing I do improves it further.

Guess I might have to call the store and have them come take a look at it because I'm convinced nothing I do will help! But thanks again for the advice

See this chart http://www.tolindsewmach.com/thread-chart.html

Tom

Oooo, thank you! That's nice to have

[Darren Brosowski]

Don't panic.

Once you master tensions all will be good.

Have you gone back to the shop that sold it to you?

[LumpenDoodle2]

If it was me, this is what I would do (assuming it sewed well before you bought it).

With the presser foot up, and the tension disks open, you should be able to pull the thread though the needle. The tension can be enough to cause deflection to the needle, but it should pull through.

Try loosening off the tension disks slightly to combat the thread being too tight when tension is off. Reset bobbin tension so that it just holds its own weight (plenty youtube vids re bobbin tension, a sewing machine is a sewing machine so almost any vid will do). Basically take everything back to the beginning.

Use some heavy material like canvas just to allow you to set up the tensions. Most of your adjustment should be for the top tension. If the machine sews the canvas well, then try some soft leather, if it sews that well, then use the leather you want to sew. This will allow you to get used to how changing the tension (and material) affects the stitch.

If you start to then hit problems, then a small adjustment should be all you need. Try one small adjustment at a time, then reset everything if it doesn't work. This shouldn't take too long as you've already set it up sewing the canvas, and you know it sews. If that makes no difference then you can try a different size needle, or lubricate the thread, or check the spring.

Before I changed springs etc, though, i'd get in touch with the seller, and get advice from them.

Just to add, it's surprising how a change to how you thread the machine affects the tension. I had problems with 'nesting' on the back of my stitch, and couldn't work out why. Then

I saw it, the thread had looped around the top post. The fix was that simple, once I saw it.

Edited September 2, 2015 by LumpenDoodle2

[HanniL]

Hi Kelsey,

Just wondering if you found out what the issue was for your machine?   As I am in the exact same predicament with the same machine. I just want to create to get my mind off things but the tension is driving me mad.

 

Cheers

Hanni
Australia