401 Stitch Problems
 

I finally cleaned up this 401 I picked up way back here

https://www.quiltingboard.com/vbulle...e-t316702.html

The sub 50deg temperatures at the workbench haven't helped much. Anyway, I'm having problems getting it to stitch well. The top thread is the light blue in the pictures, bobbin thread the gold. First, the straight stitch doesn't look very straight to me, not sure what the problem is. Also when zigzagging with the tension set around 3, the underside of the stitches have the gold reaching only about half way, as I increased the tension the stitch looked a little better, the marked lines show where I changed the tension. From what I've read here typically you want to decrease upper tension when zigzagging.

I did check the needle bar height, it was OK, the timing was off, but I fixed that according the adjuster's manual.

Any ideas or thoughts?

Did you clean the tension discs? Sometimes there's a buildup of gunk in there that interferes with tension. I don't always take them apart, sometimes just running an alcohol pad between them works.

Run your test stitches on some quilting cotton or other cloth with a finer weave. I think your wonky straight stitches are being caused by the heavy cloth/loose weave.

When I first got my 401, The cam stack didn't work. I had to oil, oil, oil. And then run, run, run. It seems like once the cam stack was running smoothly, the stitches improved too.

I can only speak about my 401, but it LOVES to be worked. If it sits too long, it gets stiff, but after a while, it works out the kinks.

Enjoy!

I agree that sometimes it is just the fabric that makes it look like it is not straight. A couple of good insights can be found at https://sewing.patternreview.com/Sew...ns/topic/28121 (by sew-classic) and https://web.archive.org/web/20110818...-about-it.aspx (another but archived by sew-classic). I thought archaic arcane had something about stitches not looking straight and/or zigzag issues, but couldn't find what I thought I remembered. I did find this about the 401 timing at https://archaicarcane.com/perfect-timing/

I thought I had read about if the bobbin thread was pulling on one side it was something simple to correct, but if on the other that it was something more complex. Unfortunately, I can't find where that was or which way is which.

Janey - Neat people never make the exciting discoveries I do.
Not affiliated with off-site link(s)

The straight stitch can look uneven if the thread and needle size are not compatible. Dirty feed dogs can contribute to poor feeding of fabric. I remove the dogs, and pick between the teeth with an old needle or dental pik tool. Soak in alcohol, toothbrush, clean and clean again. It's amazing how much lint you can pull out of those tiny Vs.

The cam stack is not a difficult clean but is a necessary one. Take photos, observe the order. Though I don't know that a sticky cam stack will impact the tension.

Have you also done a thorough cleaning of the bobbin assembly? Removing the case, crud from under the inside lip of the race, cleaning out the slots in the top lip? This will make a world of difference in how the upper thread travels around it. If you haven't, I would try this step before playing too much with the tension.

Let us know what you find.

It's a nice day today, almost 60, so back to this machine. I did the following:

1. cleaned the inside of the race, removed some crud, not the worst I've seen
2. cleaned the feed dogs
3. cleaned the bobbin case including removing the small leaf spring
4. the tension unit was already apart so I reassembled according to the adjusters manual

I tested on a lighter fabric, an old bed sheet (the first test fabric was a lighter weight denim). I also went from a size 16 needle to something a little smaller, not sure what size as it was loose in the catch all needle container. I used different threads, upper and bobbin (I don't know enough about thread sizes to say more than that).

With the straight stitch plate and straight stitch foot, the straight stitch was noticeably better, still not perfect, but it didn't look like a mini zig zag anymore. With the zig zag plate and foot I encountered the same problem, but only had to increase the tension up to 6, instead of 8 before, to get a better looking stitch, so I guess I'm making some improvement. But, if I tried to run with any speed I broke the upper thread, so that's a new problem.

This machine had quite a bit of really cruddy old oil, brown and green, all over it, and I put in quite a bit of elbow grease, so I'm not ready to consign the machine to failure status.

Janey, I am still reviewing the links you sent. Thanks for everyone's input.

JoeJr, I'm glad you had some progress. Is the thread seating well in the discs? Having to increase the tension, especially that high, is definitely not correct.

You've changed thread, so you know upper thread isn't wrapping around the spool pin from backlash, and thread isn't getting caught on the spool pin somewhere.

You're getting closer to resolving the issue. Good luck!

I'm glad you mentioned the backlash, on the first thread I used I was getting terrible backlash, none on the 2nd but my stitch problem was still there.

Is there a typical cause/fix for the backlash around the spool pin?

Are you using a stack/parallel wound spool of thread or cross wound? If the former are you using a spool pin felt? If the later are you using a thread stand so that the thread comes up before going over to the machine and going to the first thread guide in the same position as if using a stack wound spool? I think that would help some. Some good info about the difference and ways to get it to work can be found at https://archaicarcane.com/standing-a...s-stack-wound/. Courtney made one that should work on your machine if the cross wound spools aren't too big. He gave permission to post the pdf at https://www.quiltingboard.com/showpo...&postcount=146 One needs to be sure to wrap around as illustrated.


Janey - Neat people never make the exciting discoveries I do.

Not affiliated with off-site link(s)

Thanks Janey.

Clearly I have more work to do on this one. For now it's under a cover, off to the side, while I clean other machines. But I will get back to all this after it rolls around in my head for awhile.