Help...bottom thread tension problem

[TimberWolf]

My bottom thread tension, all of a sudden, is looking like crap! This is on my Juki 241 flat machine.

I tried adjusting the bobbin tension slightly, but no change. Thread size is 138, same as I have been using for years. The photo shows the bad stitches on the top sample. The bottom sample was from a piece I had sewn a few days ago and is how it should look. How can I correct this? Any ideas? Thanks,

Tim

[wolvenstien]

you thought about using a hammer on it? Usually works for me.... Other than the bobbin tension, I have no clue... you loosen the top tension? tighten the botton, looen the top and see what that gets you?

Glad to see you around.... you havent been posting for a while....

[william]

Thread might be catching in the bobbin, Might need to re tread the bobbin.

[JohnsCustomLeather]

Try turning your bobbin so the thread comes off the other way.

You may have it in upside down.

John

[bcurrier]

It actually looks more like a top tension problem. While the general rule is to look to bottom tension for a problem on the bottom, top tension for a problem on the top, I don't see any indication of top thread takeup - at all - on the sample you provided, nor does the bottom thread look ramrod tight. In fact, the latter looks loose on the right side of the photo.

Bill

[Luke Hatley]

this has happened to me before. completly re -thread the machine,

re wind a bobbin and start all over.

from the photo it looks to me like, top tension needs to be

tighter or bobbin tension need to be losen up so the top thread can pull the

bottom thread up into the leathers.... it can be confusion some times.

[Art]

Hi Tim,

When problems show up suddenly, it is usually something simple. Take all thread out of the machine, clean and oil it. Blow out to bobbin case and race and re-oil it, use an inspection mirror and light and just check everything. Follow each thread path and make sure there is nothing to hang up on, this includes burrs and sharp edges. Put a new needle in the machine and re thread it. Try and thread the same way you did before. Pay attention to the way the thread is coming off the spool as this can change tension drastically. Now when you have everything clean and smooth, sew off and adjust tension as you would normally. If you see top on the bottom increase top tension, if you see bobbin thread on the top decrease top tension. If top tension is too loose when you get the lock right, you will need to increase the bobbin tension some, but do this as a last resort.

It doesn't take more than 15 min to 30 min to clean, reset, and inspect the whole machine. In the canvas trade they run with the same thread like forever and never do anything (including oil) except change bobbins (mostly pre-filled). The machine starts acting funny and they go bonkers and start adjusting without thinking and then I get a call. Generally, all I do is what I said above, strip it, inspect it, oil it, new needle, new bobbin, check timing (rarely a problem, about 10% of the time), re-thread, sew off and adjust. ZigZag machines for sails are more of a problem as there is more to go wrong, but the upholstery and leather trades rarely have those machines or problems.

When something goes wrong, just go back to the basics.

Art

My bottom thread tension, all of a sudden, is looking like crap! This is on my Juki 241 flat machine.

I tried adjusting the bobbin tension slightly, but no change. Thread size is 138, same as I have been using for years. The photo shows the bad stitches on the top sample. The bottom sample was from a piece I had sewn a few days ago and is how it should look. How can I correct this? Any ideas? Thanks,

Tim

[TimberWolf]

Thanks for the replies. I think I found the reason...it is the new thread I am using. No tension tweeking combinations helped, so I got to thinking maybe it is the thread and not the machine. Sure enough, I had a little thread left on a cone from my usual supplier, so I filled the bobbin and used the old thread on top as well. Perfect looking stitches! I just stated using this other brand of 138 this morning, and that is where the problems began.Visually, the new thread looks fine, but for some reason it doesn't perform well at all in my Juki. Just placed an order for more 138 from my old supplier. This new thread can go into the round file.

Tim

Edited February 1, 2008 by TimberWolf

[bcurrier]

Out of curiosity, what were both the old and new threads? I'm amazed that swapping out one for another in the same size caused such a dramatic tension problem.

Bill

[TimberWolf]

Bill, The new thread came from "The Thread Exchage". There was a post on the forum a while back, so I thought I would try them. My usual supplier is Southen Textile Group, out of Chattanooga Tn. http://www.stgroup.org

The main reason I tried the new supplier was because they had small cones of 138 in colors.

I called Thread Exchange, and Bob was very nice about the problem and offered a refund, but had no idea why it doesn't sew well in my Juki.

Tim

[Art]

Hi Tim,

In my machines, Eddington always has more drag than Coats. Black and Burgandy have more drag than white. I lube everything in the bigger sizes (207 up) which seems to even the field a little. Nobody likes to throw a $20 spool of thread. All thread is definitely not the same so adjusting is necessary. The big users buy in lots so it's not a problem for them. Even the sizes are just general suggestions, and often the colors are too. Wait till you go to an auction and there are 20 or 30 spools of thread in a lot and you can't resist so you buy it for $4, none of it is labeled and it all sews differently. I've narrowed my stock down somewhat, White, Brown or shades thereof. Black, natural/straw and linen are about it in Linhanyl nylon for up to 138 and Coats poly for 207 to 512. The Linhanyl is a buy right now from Artisan for $12 a pound, Coats almost always is $18-$20. The Linhanyl and Coats are pretty tight layed, I keep the Eddington because it is wound a little looser and is better for reproduction work if I don't use the linen on the Campbell.

Art

Bill, The new thread came from "The Thread Exchage". There was a post on the forum a while back, so I thought I would try them. My usual supplier is Southen Textile Group, out of Chattanooga Tn. http://www.stgroup.org

The main reason I tried the new supplier was because they had small cones of 138 in colors.

I called Thread Exchange, and Bob was very nice about the problem and offered a refund, but had no idea why it doesn't sew well in my Juki.

Tim

[TimberWolf]

Art, Thanks for the post. Before I figured out the whole problem was the thread itself, I was ready to call my service guy to come look at the Juki. Think I will stay with the same brand I have been using for years. I don't have the patience to experiment and tweek the settings to accomodate new thread. Surprising that just a different brand of thread can do that to a machine.

Tim

[Art]

Hi Tim,

That's not the only thing. If you buy from a repackager (they buy thread on the monstrous spools and split it down to pound or fractional pound sizes), it makes a difference how they wind it on the spool, I have seen cases where simply turning the spool over made all the difference in sewing (it stopped a kinking problem). Some folks pay the thread off the spool like a home sewing machine and it actually makes a difference which side it comes off. This all comes from how the spool was put up.

Art

Art, Thanks for the post. Before I figured out the whole problem was the thread itself, I was ready to call my service guy to come look at the Juki. Think I will stay with the same brand I have been using for years. I don't have the patience to experiment and tweek the settings to accomodate new thread. Surprising that just a different brand of thread can do that to a machine.

Tim

[esantoro]

I've been wondering about this same thing about the direction of winding bobbins when I wind with a power drill.

On another note, I recently got some Eddington in from Campbell Boswoth. I like it a lot. Very nice chestnut, the very color I had wanted and very nice texture. I would even say the texture looks a tad more natural than that of Coats.

It also seems that Eddington is easier to get than coats and in a larger range of colors. Black and White also seem to be economically priced quite often.

Ed