miriam

Did anybody say anything about not getting the top thread between the disks... Kinda basic but I've done it...

Mickey2

There's 7 pages in the thread, and I haven't the chance to go through it all until later. I struggle a bit with tension and going from fine threads and needle to heavy duty; all within what I call normal range, up to top-stitch thread thickness. Are there clever ways to fine tune bobbin tension and upper tension for the different threads?

Sammie1

Me too!


I adjusted the foot pressure. I hadn't moved it since I got it and was surprised at how much I had to back it off. I'm not certain if there's a trick to making sure the foot pressure is right, but I backed the pressure off quite a few turns and it solved my other problem with not being able to sew on a curve without puckering. Not sure what fabric would require so much pressure? My test fabric was two layers of muslin.

Thanks!

ArchaicArcane

I'm pretty sure that I came up with that when I was teaching someone to use their machine so your google-fu didn't fail you.. Basically, with a properly formed well tensioned stitch, the thread should recess in and you should just see the top of the opposite side's stitch, like looking down at a bald headed man's head. If the head is furry, you might want to change threads to something less linty!! Some people think that the stitch is wrong because they can see the bobbin thread on the top or the top thread on the bottom - it's not really, depending on where you see it. When you use 2 different colored threads especially, you will see the stitch in the top thread, then a dot of the bottom thread, the stitch, the dot. The dot is the bald headed man. If it's not sticking up so you can feel it - railroad tracks - then it's OK.

This comes back to what I said several pages back. This is why I don't recommend "un-threading and re-threading" I'm fairly sure something was mis-threaded but we can't prove it because during the act of changing threads, we didn't examine the current thread path that was causing issues. Like Miriam mentions, if a tensioner is threaded wrong - i.e. thread behind the disks instead of between them - it would behave like this. Likewise, if something was snagged in the bobbincase or hook area, the bobbin thread would have been way too tight.

When I run into trouble like this, I examine the thread path - I don't re-thread, I find where the problem is. When I find it, I fix that part and test again. That helps me know where a problem is likely to recur and what I need to keep an eye on.

For example, some of the early Pfaff QE4 machines had a problem with the take up lever un-threading. If this were one of those machines, you've probably go mad re-threading all the time. I know I would. If though, we examine the thread path and found the thread out of the take up lever, we'd know it was a spot to keep an eye on, or (as in that case) it was a reason to take the machine back and have the "update" done to it.

Behind, in front of, simply not flossed into the tension disks - either from not threading carefully or from threading with the presser foot down - thus engaging the tension disks making them harder to get the thread into.

Yes, another point - presser foot up always when threading the tension disks. After that, you can put the presser foot down if you want.

In fact, this is the way I typically thread (which drives modern machines buggy and makes them beep at me!):

1. Presser foot up or down until I reach the tensioner.
2. Presser foot up to disengage the tension disks
3. Thread through the tensioner
4. Presser foot down, and if it's an external tensioner, grab the threads on both sides of the tensioner and make sure the thread is fully seated into the tensioner (for a 201 for instance, I would grab both threads and give a gentle upwards tug)
5. Continue threading the machine.

The main reason I put the presser foot down for the rest is clearance for my hands when threading the needle and so I know nothing's jumping out of anywhere.

I could swear we've talked about this before but here it is in detail.

A bobbin case's tension should be set to about 1oz. This will change from thread to thread - a thicker thread will have more resistance than a thin thread, similarly a coarser thread will have more resistance than a slippery thread. Therefore, a thicker/coarser thread will need the bobbin tension loosened to have a 1oz pull. A thinner/slippery thread will need the tension tightened to achieve the 1 oz.

Once you have one known good scientifically set condition - your bobbin thread tension - you can adjust your top tension accordingly for a nice balanced stitch.

This works even with more challenging threads like metallics - they need very light tension or they break.

Incidentally, this is why "automatically" tensioners fail. They assume a 50wt thread and set themselves to a "4", or in the case of newer still machines they set themselves to whatever has been preset in the software but still assuming a 50wt thread. For instance, a very new machine that does "adjust" tension based on the stitch may drop from a 4 to say a 3.2 for tension when you change to a wide zig zag from a straight stitch but that's still assuming based on a 50wt thread.

Now, here are a couple of gotchas:

1. Whose 50wt thread did they use for the setting? Thread weights (at least the wt system) are not standard. A 50wt 2ply thread is different than a 50wt 3ply thread and Gutermann's 50wt is visibly different than Aurifil's 50wt.

2. The change made to tension by an "automatic" machine does not involve the bobbin case tension. This means that more than likely the stitch will unbalance. This is considered acceptable for 2 reasons - 1. People don't like to/know how to/the technician doesn't want to show people how to/trainers don't teach people how to set bobbin tension properly 2. We're taught that, typically, we don't see the backside and would match thread colors anyway. In fact, I've seen it written in owner's manuals that it's OK to have top thread on the backside for decorative stitches.

I wouldn't say it was necessarily a particular fabric that required that. Little hands mess up machines like crazy because they're fascinated by the dials and knobs. Bigger hands mess machines up, often in frustration when they can't get the result they're looking for and then sometimes the machine ends up going out the door into someone else's life and becomes their "problem".

mim

I went to a thread lecture years ago and learned that winding a bobbin too fast tends to pull the thread a bit tighter.

Also you might want to discuss what happens when using different weights top and bottom.

Mim

miriam

Another duh thing. Always adjust the tension with the foot down so there is tension on the tensioner...

ArchaicArcane

I've seen plastic bobbins destroyed by winding nylon too tight.
Different weights top and bottom can create some balancing challenges but I don't discourage it because it's a "technique" that a lot of long arm quilters use.

I don't typically care whether the foot is up or down. Either way, once the release pin is dis-engaged (and the discs are engaged), the tension adjustment will be noticed. If the foot is up when I remember to make the change, I change it then. I don't put the foot down to do it. It's a mechanical device - even with a pulse motor - and it will be tighter when I go to sew regardless of when I turned the dial up.

KenmoreGal2

That's excellent Tammi! Thanks, this is all so helpful for me. I can't be the only one....

ArchaicArcane

I just finished my presentation thanks to everyone's input!

Now I just have to gather the things I want to take as 'props' and demos.

I should make it on time for tomorrow at 6pm - test sews, a 201 to prep - remove dogs, retaining finger, slide plate, throat plate, etc. -, a roll of toilet paper - what better way to show the twist in stack wound thread when you pull it off the end instead of rolling it off the side. - and several types of thread to pack and I'm done.

miriam

This needs to be a sticky