In the last post, we talked about ways that thread nests can be solved from a user point of view. Today, I’m getting into the slightly more technical ways that the nests happen and how to deal with them, or when to take it in for service.
Category 2: Possibly user fixable or take it in – Depending on skill and comfort level
Reason #4: There be fuzzies (and dried oil and other grunge) between those disks!
A natural byproduct of sewing, especially with cotton thread is lint. Take a really close look at your thread. You’ll notice that it’s a little frizzy. There’s the main body of the thread and then there are short little lint sized protrusions all over.
As your thread passes through the tension, a lot of these protrusions are yanked off and left behind in the tensioner. When they all gang up together they can push the tension disks apart, simulating the action of the presser foot lever and that “pin” we talked about earlier.
Solution: I’ve heard of people “flossing” their tensioners to remove the lint, and I’ve even recommended it in the past. Dental Floss and serger chains have been known to work well in some situations here.
In some cases this can help – in others it will compact the lint further in – compounding the issue. The other thing that is a risk with the serger chain is that there is a possibility that the serger thread can break inside the tensioner, also compounding the issue. This may have happened recently in a machine that hit my bench for a “no tension” problem. When I disassembled the tensioner, I found a 12″ piece of thread all wound up in between the tension disks. It was all one piece, so I can’t tell if it was a piece of the chain or part of the preexisting problem, but as a result, I don’t recommend the serger chain anymore.
Truly, the only “surefire” way to make sure all fuzzies and grunge are evicted is with dis-assembly.
The last 3 reasons are things that you may need to take a machine to the spa for.
Please be honest when evaluating your skill and comfort level when deciding if you want to do this or take it in to be repaired. Few service people I know – both the hobbyists and professionals alike – enjoy receiving a baggie of parts and a machine someone else has tried to fix prior to bringing it to them to reassemble.
Reason #5: The tensioner is mis-assembled or missing pieces (and thus also mis-assembled)
In some cases, this is obvious (visibly missing pieces or something sitting off kilter) but I’m assuming that in the case that brought you to this post, it’s not obvious. 🙂
Solution: Disassemble, clean (at the very least) all surfaces that touch the thread and reassemble the tensioner.
In the case of a vintage machine, you might be able to use one of the disassembly and reassembly videos that I posted here on YouTube a couple of months ago:
On Machine Disassembly and Reassembly of a Vintage Singer Sewing Machine Tensioner
Disassemble and Reassemble a Vintage Singer Sewing Machine Tensioner
Additionally, this TFSR.org document is quite useful for the same machines. 2016-10-21 The manuals from TFSR are offline at this time. They can still be found at: https://web.archive.org/web/20160901183756/http:/www.tfsr.org:80/publications/technical_information/sewing_machine_manual/
In the case of the newer machines, computerized ones especially, the tensioner units are controlled by pulse motors and electronically “set”, so these are best to take to a qualified repair person to fix.
Category 3: Strongly consider taking it in or only for the advanced repair hobbyist.
Reason #6 -On some machines, there’s an adjustment that needs to be done for the thread clearance at the hook.
This problem typically manifests on a machine after a thread nest has occurred, and we’ve been a little too rough removing the thread. When I say we, I mean as sewists, not as repair persons. 🙂
At the hook on some vertical hook machines, there’s a “finger” that holds the hook race from rotating too much. Its job is to hold that there, but it needs to be far enough away from the race to let the thread pass behind it.
Sometimes when we get frustrated by another nest, or delay or whatever, and we yank the thread out by the material, we can bend that finger or pull or push it out of adjustment, causing a clearance problem. This usually begets more nests, causing more frustration…. and on it goes until we want to throw the machine out the window.
On some machines, this is fairly difficult to get to, on others it’s reasonably easy, but in most cases, I would suggest that someone who’s got access to the specs and possibly who’s been trained to do this work should fix your machine.
The machine you see in that photo has had a clearance problem since the day I bought it (used). After I did these last 2 posts for you, I finally got around to making the adjustment. Seriously. I lived with it for 2 ½ years like this. I just did my best not to end up with nests to deal with. 😉 It really can be true what they say: Mechanics have the worst running cars, sewing machine technicians have the worst running sewing machines. Good thing so many sewing techs don’t sew, eh?
*video for “safer thread jam clearing” to be inserted here once I reshoot it. I just didn’t like how it turned out. 😉 When it’s here, I will update the title of this post with “(Updated with video)”
Reason #7 – This last reason is by far the least common reason for nests (it usually causes other issues we’ll talk about later in the series), but it’s a valid reason, so if you’ve exhausted the other reasons, this may be the issue. This one I STRONGLY recommend be remedied by someone experienced with this sort of repair.
In some cases, a needle strike on some surface in the hook area can cause a burr. This little furrow of metal can catch the needle thread as it travels around the hook area and not let it go.
It’s a relatively easy situation to test but delicate to repair correctly – depending on the location of the burr – without causing more damage.
Due to the very real possibility of causing more damage, I am not going to cover how to repair that on this post but just mention that it can be a cause of nests and suggest ways to find them.
Needle plates and various parts of the rotating parts of the hook can catch the thread.
The best way to test this is to set your machine up as if to sew: thread it put fabric under the presser foot, set your tension appropriately, insert a bobbin in the case and the case into the machine (if applicable), drop the presser foot.
Here’s where it changes a little. Make sure that you can see the hook mechanism clearly. This may mean leaving a slide plate open, or a panel so that you can see the hook and bobbin area. With the bobbin case and the bobbin in place – rotate the handwheel for 3 or so revolutions and see if the thread looks like it’s catching somewhere. If it catches, a close look at that area will likely reveal the burr or other issue.
This is a good thing to point out to your repair person so they know where to concentrate their efforts.