bobbin tension issues

[whitewater]

3 words...

Read The Manual

 

[Gilligan]

thanks Moose, I am oiling it up. here's my steps. grab a new bobbin, put it in a clean case, check tension reading, adjust as needed. trying to be in the 180-200 range on my meter. Put the bobbin in, start sewing. sews, trims, looks great....half way through the design it all goes to f...pull out the bobbin, check the tension and it dropped to under 100... all 3 machines are doing it. Thing is, it will sew perfect for a shirt or two then go wonky for an hour. I'll try slowing them down and see if that helps.

Gilly... who doesn't...?

...The card attached would say...

[mooseman]

Homer
you mentioned you bought all new bobbin cases for all your machines. I would focus on them as either they are rubbing on something and heating up or they may just be junk. Go back to ONE of your old bobbin cases and try that relative to the new case.
There is no real reason for the actual tension to change unless something mechanical is happening, heat, loose screw, etc.
PS someone who had a ton more embroidery experience than me told me a long time ago..when you change stuff change one thing at a time , take time to understand the result and go from there. If you change a bunch of stuff you will have no idea WTF happened wrong or right.
If all else fails this guy is pretty good and local, $50.00 to get him there as I recall. He serviced my machines about a year ago, nice job, knows his stuff.  http://www.doctorcarlsewandvac.com/
mooseman

[Prōdigium]

PS someone who had a ton more embroidery experience than me told me a long time ago..when you change stuff change one thing at a time , take time to understand the result and go from there. If you change a bunch of stuff you will have no idea WTF happened wrong or right.

That has something to do with embroidery, but with EVERYTHING in life.....Start turning all the screws in life like a madman and quickly you will find things go out of control. Learned this lesson long ago working as an auto tech.

As a person who knows next to nothing about embroidery and often has a hard time spelling it, I would say your on target. Go back to what you know works, make controlled steps to ascertain the problem.

[Homer]

thanks, that's exactly what I do. I am keeping a log on all our changes on each machine to see what happens. I'm going in today to see if I can nail this down. thanks for the help guys.

[JBLUE]

Sh!tty bobbin cases will do this from time to time as well. When they get warm the spring softens which is backwards from what you would think. Then it cools back down and works fine.

[Itsa Little CrOoked]

Jay, I can't imagine how this could be your problem....but it might be worth mentioning. It's mostly a word of encouragement, I guess.

Once a couple of years ago, I DID HAVE an issue with a single rotary hook on 1 (one) head of my 4 head Tajima. I had previously been setting radically different UPPER AND LOWER tensions on that particular head to match the results of the other heads. The bobbin tensions were repeatedly measured on a TOWA gauge and the cheapo stick guage for upper tensions, and NEVER EVER would work the same as the other heads.

Turns out, it was a rotary hook the whole time. I still can barely believe it.... I replaced that hook and BOOM! The problem vanished instantly. (It just can't be, but I assure you....It was!) I had been scratching my head and posting to embroidery forums and Tajima user groups for a long period of time, but never got an answer until someone finally suggested replacing the rotary hook on that head. I thought what the heck. I may as well "cast my net on the other side of the boat". I'm still in a state of disbelief that the hook could have been the problem.

The rotary hook doesn't sound like your issue, except to say, don't be afraid to think outside the box. It's just a machine, no magic is involved. It's possible you are missing something basic. Dunno what, but you'll figure this out.

[mk162]

I really want to know what is causing this.  It just seems crazy

[Admiral]

It seems you are doing something wrong with the bobbin then.  Like the springs are dirty or you aren't threading them right.

that's why I use the magnetic ones 

It has been fine for the past, ohhh 4 years....then few weeks ago it married it's cousin or some damn thing. I don't freakin know. maybe I am.

Magnetic core or magnetic side?

I threw out the magnetic side ones right after we tried those...

[Doug B]

  I threw out the magnetic core ones. I also foung out just today that there
was a LOT of lint built up in the bobbin cases. The whole machine is running
much better after cleaning.

[mk162]

I didn't know magnetic side ones existed.  We use the Filtec MagnaGildes.  I doubt we will go back to paper sided.  Too much dust and lint buildup form the cardboard.

[Homer]

I might have this fixed.

I tried mag sided and mag core. I have 2 or 3 boxes of madeira magnetic sided bobbins of anyone wants them. piece 'sh*t they are.

I have a towa M-1 gauge, it reads in Nm from 100-400. From what I have found online, it should read 180-220 for the tension. had them running great on saturday, fire up this morning a, put it in my gauge and it was reading off the charts, over 400. put it in the machine and a little tweaking, them bastards have been running nonstop for 2 hours now.

the only thing that changed was going from mag core to sided bobbins, and then 2 days later going right back to mag core.  that's when it all started. So now I need to find a different gauge I guess.

[inkman996]

I might have this fixed.

I tried mag sided and mag core. I have 2 or 3 boxes of madeira magnetic sided bobbins of anyone wants them. piece 'sh*t they are.

I have a towa M-1 gauge, it reads in Nm from 100-400. From what I have found online, it should read 180-220 for the tension. had them running great on saturday, fire up this morning a, put it in my gauge and it was reading off the charts, over 400. put it in the machine and a little tweaking, them bastards have been running nonstop for 2 hours now.

the only thing that changed was going from mag core to sided bobbins, and then 2 days later going right back to mag core.  that's when it all started. So now I need to find a different gauge I guess.

Never used a gauge never will. Any good operator will be able to do the drop test and have the tension perfect just from feel and knowledge of how the machine likes to run. Don't know about your tech but every tech ever in our shop says the same thing, stay away from the gauges, learn the feel for your self and you are good to go. Some shops by the guage and end up chasing a tension that they think is supposed to work but it simply won't on their particular machine.

[Doug B]

  I have used a gauge. I think it was on a Tuesday. They are not indicative of the
way tension should be on every machine. I use both L and M bobbins on two different
machines. I have NEVER been able to set tension "by the book" and have it work
flawlessly.

[Homer]

well now you tell me, thanks guys  ...I just assumed that was the correct way to go about it. I want anyone walking up to the machine to have the same settings. I guess it doesn't work that way. great! another variable. 

so you're saying I should take the gauge to the range? excellent.