Singer 411G stitching issues

I bought this machine on the price alone, and thought I'd start by cleaning it. After cleaning it wasn't stitching well, so I assumed (correctly) that something I did had caused it to go out of balance.

The 411G has gold accents

The symptoms were that threads were nesting badly in the bobbin area. After perusing the 401 service manual thanks to Sewing Dude (https://sewingdude.files.wordpress.com/2012/09/singer-401-service-manual1.pdf page 131), I decided to go through and check the clearances for the bobbin case (which seemed very loose even before I cleaned it) and anything else in the bobbin area.

So this is the procedure:

Remove the needle, remove the presser foot, slide the slide plate (1) back, lift and remove the stitch plate (2).

If you want to (it's not necessary) you can also remove the slide plate. It's just like the 66 and 99. Put down the platform that holds the stitch plate then slide the plate back until it clears the spring.

You should now see this (without the arrows of course)

You will need a set of narrow feeler gauges to check the clearance. If you don't have any, you'll need to get some or guess the gap.

Narrow feeler gauges

Using the picture with the arrows, check the gap marked 1. It should be 12-14 thousandths of an inch (thou). If it's not in that range, go on to check 2, the vertical clearance between the hook and the spring, 16-18 thou. These are both adjusted at the same time, by loosening the two screws marked by thick white arrows and moving it until the clearance is right, then re-tighten the screws.

Once you've done this, check 3, the distance between the bobbin case and the spring. If this is not between 12 and 14 thou, adjust it. The adjustment is easy, but you first need to remove the machine's plastic base (two screws), exposing the locking screw (see picture below).

lock screw for adjusting bobbin case clearance

Once you've loosened it, you can turn the screw to the right of the bobbin spring (see below) which is eccentric and will increase or decrease the gap. 

Once this clearance is right, perform a test sew. My machine was made to sew at full speed with a very narrow stitch length and making a pattern, the ultimate test. It didn't skip any stitches or even hint of bunching up. Machines like this that do everything are a lot more complex than, say, a 15 or 201 so they need more attention and are harder to get to, but with the right resources (mostly just knowledge) you can keep them in top condition. 

Another problem was varying speed during sewing. This means that the foot controller's carbon pile needs a clean. This is a horrible job, so I replaced the controller. Later on I pulled out a Japanese electronic controller I've had for a few years and that was even better, because apparently you can leave these plugged in without any heating (the 411's controller was also quite hot when I changed it). The electronic replacement required a little soldering.

It's now almost perfect. The last job is to see why the motor is noisy. A drop of tri-flow was suggested on another blog, but it hasn't quietened it, so I'm thinking I'll have to remove and disassemble. Not a job I'm looking forward to, since it's completely enclosed, but I'll do it and let you know of any obstacles.

Adjusting your thread tension

Before starting, remember that the bobbin tension must always be less than the top thread tension.

Some problems and their solutions.

Problem: puckering

Cause: Assuming here that you have already adjusted your presser foot. If your thread tension is too tight, the thread will pucker the fabric as you sew. Reason is that the thread pulls the seam together. It looks terrible and makes your work look cheap (look at the seams on a cheap shirt that has been worn a few times).

Solution: Loosen the top thread tension. 

Problem: Snapping thread

Cause: see above, or maybe you're using vintage cotton thread. 

Solution: If the latter, just know that old cotton is generally not usable for sewing. Throw it out or use it for a display.

Problem: thread loose and loopy at the bottom

Cause: Top tension is too loose

Solution: Increase top thread tension

Problem: Thread loose and loopy at the top

Cause: Bobbin tension is too loose

Solution: Increase bobbin thread tension.

More likely you'll have something in between and your stitches aren't balanced. Your stitches should be perfectly balanced, with a dot from the bottom just visible between top stitches and a dot of the top thread just visible between stitches at the bottom. Test this using contrasting coloured threads.

Top tension

Almost all tension problems can be fixed by adjusting or fixing the top thread. The sewing machine was designed like this so you don't have to fiddle about with the bobbin, which is always more difficult than adjusting the top.

Thread your needle, making sure the thread is between the tension discs. 

Make sure you thread it with the foot up. Reason is that when the foot is down, the discs are pressing together and will not allow the thread to sit between them. Then there is absolutely no tension on the discs. If there's no tension, chances are you threaded it while the foot was down.

Now put the foot down and pull lightly on the thread, through the needle. Not hard, and the thread should deflect (bend) the needle. Now turn the top tension toward zero. At around 1 the thread will start moving and at zero there should be almost no resistance at all. If this is not the case, you will need to adjust, or calibrate, your tension dial. If you don't want to, just don't rely on the numbers. From zero, most machines are happy for normal clothing fabric at around 2.5 to 3.5, at least on my old Singers.

I'm not going to tell you how to calibrate your machine's tension dial because your machine will almost certainly not be like mine.

Bobbin tension

If you absolutely must do this, how you do it will depend on whether it has a vertical bobbin (with removable bobbin case) or horizontal (drop-in bobbin - non-removable bobbin case).

Vertical bobbin machines: Remove the case and holding the end of the bobbin thread, let the rest (bobbin and case) hang. It should only just be able to stay still so that if you move the end of the thread up at all the thread will unravel. If this is not the case, adjust by turning the little screw in to tighten or out to loosen. Keep testing until it is perfectly balanced. Adjuster is on the tension spring, which the thread passes through.

Horizontal bobbin: Thread it through the throat plate like you were preparing to sew. Pull the end and adjust as neccesary so you just feel a little tension on the thread. Adjuster is on the tension spring.

Before I learned about all of this I probably shook with fear if a machine's tension wasn't right, but it's really not that bad. If it loops, the side opposite to the loop is too loose. If puckering, loosen the top off. For puckering, check the foot pressure before adjusting the tension or you'll have to fix the tension afterwards.

Threading a Pinnock

It's easy to make it "Threading a Sewing Machine" but my daughter's Singer is not the same as any of my machines. Hers has a built in bobbin holder, where you just drop a bobbin in. Mine is different, and it's the only other one I've had experience on: It has a removable bobbin holder which is very common I've noticed. Also very expensive. A couple of months ago I went to a sewing shop in Thornbury and she charges $20 for a new one!! I didn't get it and a week or so later I'd bought another machine from the tip shop and it had some spares.
The bobbin tension is a real pain in the proverbial if you don't get it right, but it's really quite simple once you've seen it. There are a great many videos made that are on youtube and instructions just about everywhere, but rather than recommend one of these (you can Google for yourself I'm sure) here is my brief guide, using my partner's new (?) machine ($2 at a garage sale - yes really, but I had to clean it, oil it, grease it, give it a base and test it).
Before threading your new old machine, give it a really good clean. Thread carries and creates a lot of dust which gets stuck everywhere thread goes. The thread path plus the feed dogs and the bobbin case. All the Pinnocks I've had so far have an easily removable bobbin case, so remove it and remove all the dust and bits of thread.

1. Foot tension. I only mention this since it's a major cause of puckering. If you're getting puckering, release this a little. 2. Thread goes through this hole 3. Tensioner. Just wind it around 4. ... then back over the spring then down so it 5. ...goes around the arm.Thread through the take up arm at the top then down.	Thread through everything that looks like it will guide the thread, then through your needle. Thread goes through the needle from left to right or front to back, depending on your model.
same, but from the side	My rusty bobbin holder. The thread must do a U-turn to enter the bobbin holder's thread slot.
pull thread back toward the protruding arm. Note the tension screw in this photo	and through the hole.

And that's how to do it. Not hard but trial and error is a harsh teacher, so I hope I've saved someone some time.
EDIT (thanks Greg Livingston): Download the manual here