MeganMills

I cannot find it now but I know a couple of times I've seen something online to say that in addition to the stitches "meeting in the middle" and the stitches "locking" to create a strong seam (without puckering) another sign of good tension is that when you turn a corner the stitches look the same top and bottom.

A fair proportion of the time mine do - and a fair proportion of the time (on the same line of sample stitching) they don't and there is a little "loop" of the top thread pulled under. (Or - if I adjust tensions the other way dramatically - a loop appears on top.) This pulls the corner/angle stitches "out of square" (or whatever angle it is you're aiming for) on that side and is unattractive when both sides can be seen. And it irks me.

I've been experimenting on my circa 1902-1903 Singer 28K to try to find just exactly when in the stroke of the needle being "down but rising" is the right time to lift the presser foot, turn and pivot as I have a suspicion that if the tension is otherwise lovely in every respect this might be the variable factor that makes some corners great top-and-bottom and others less so.

The green is the top thread. The stitch length is set at the longest setting and I'm using 50wt Aurifil cotton thread. There is puckering in the fabric because the first tests were too loose top and bottom so looked lovely but pulled right out - no better than basting. So I tightened up in the other direction so it locked like crazy but puckered. Then I incrementally notched it down bit-by-bit. (This has meant playing with both top and bottom tensions. The shorter seams closest to the outside corner is the most recent testing. I started on the longest seams.)

No matter what I do a tiny dot of the other colour shows on each side and I'm fairly sure this is simply because if the fabric isn't particularly thick there isn't sufficient "between the fabric" space for the threads to twist around each other between the two. So long as the dots are the same on each side, the seam is strong, and neither thread pulls out more easily than the other I'm assuming the tensions are reasonably well balanced.

So - any advice on the ideal point in the stroke to stop and pivot please - and is it different for different straight stitch vintage machines that don't have a "needle down" option which decides for you?

And does anyone else remember that online source that speaks about corners the same top-and-bottom being another indicator of good tension?

Thanks heaps... Megan

OurWorkbench

I'm wondering why you are stitching on a single layer with the longest stitch length. What size needle? The 28 has an extra motion that many later vintage machines didn't have. Indeed, that would probably make it a little harder to make a square corner. There is a "Singer's Sewing Skills Reference Book" that tells how to make square corners like for points (or probably pockets) or collars on page 13 of http://ismacs.net/singer_sewing_mach...rence-book.pdf

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

Oh - sorry Janey. I should have said. It is a double layer of fabric. You can see that the top side shows some embroidery and the bobbin side doesn't because it's a separate layer. At the outer corner on the bobbin side it's easier to see it is two layers because they don't line up. The layers appear to be either a linen or cotton. It's a bit of crazy patch stuff that came with one of my machines. I think one layer used to be a tablecloth and one used to be a napkin or handkerchief. They're on the slightly heavier side of lightweight fabrics but are very soft because they're old. I'm using a size 70/10 Schmetz Universal needle (new).

Thank you for the link to the reference books - I love things like that! And you're right, the little "hoppy" bit has had me tinkering around with all sorts of needle positions to try before pivoting because the needle is down more than once and rises more than once. One thing I read for Featherweights said to pivot just as the eye enters the fabric as the needle is going down. That produced consistently terrible corners on this machine.

MeganMills

Hmmm - one thing I've noticed is that corners turned one way are always a lot better (often almost perfect) compared to corners turned the other way... you can even see it in the samples I did - the turners where I had to turn clockwise fare better. I'm thinking that when you turn the fabric to make a corner you are twisting the needle and bobbin threads. Perhaps a small clockwise turn is okay - but anti-clockwise has a negative effect. What do you think? Balderdash or?

(This still happened when I changed to a new 80/12 Schmetz Universal needle too, which I did after looking up info on the 50wt cotton and realising that most people say it should take the 80/12 needle - not the 70/10.)

I've tried always turning the fabric clockwise but that can require a 3/4 turn and the "normal, better turn" is a 1/4 turn. That 3/4 turn doesn't look great either on the bobbin side.

Thanks again for any thoughts on any of this... Megan

OurWorkbench

That is an interesting observation. I'm wondering if it has something to do with the side that loop is on (based on which side the flat of the needle is). I know there is a different narrow hemmer that was for the vintage low shank machines. While they will work on all, it was better stitching with the one that was meant for the designated machine. I wondered why the difference and figured that it was the direction the needle was threaded. I'm wondering if 221, 201, 15-90 or 15-91 would work better on the anti-clockwise corner????

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

Watson

IMO, your top tension is too strong in these pics and is pulling your bobbin thread up. This will also give you the extra bit seen on the corners.
I would re-thread the bobbin into the bobbin case and try again. If it continues, regardless of how you re-set the top tension, it is likely a bobbin tension thing and you may need to adjust the bobbin tension a tiny bit tighter.
Have you ever had correct stitches or is this a new thing?

Watson

Hooligan

@MeganMills i would agree with Watson above and would consider this a tension issue also from the pics shown

OurWorkbench

I feel that the tension is actually pretty close to 'right on' with just a peek of the other side where they meet on the straight stitches. The thread that is pulled to the other side on the corners is actually the bobbin thread drawing the top thread to the underside. Corners are tricky and so trying to get the needle in the correct position to pivot so that they are square on both sides is where the 'problem' is coming in.

I thought Archaic Arcane did a post about tension and stitches that was very good, but I can't find the one about the stitches right now.

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

MeganMills

Hi Janey,

I agree with you - and if I tweaked the tension a bit either way I'd get the "unsquare" problem happening on the other side - where I ended up was about as close to perfect as I could get it.

But - I have an update that means Hooligan and Watson were kinda on to something just the same. I got a replacement shuttle from (a proper Singer original vintage one for this model) and the machine instantly ran more quietly. I thought this was a slightly noisy machine - it turns out (it seems) that it was a "noisy shuttle"! Well - blow me down!

So I set the tensions the normal way I do - just like I had on the other shuttle. It seems to have solved the problem. I stitched 6 perfect corners in a row. Three turning clockwise and three anticlockwise. I'm not quite sure what the difference is. I'd checked the shuttle clearances on the other shuttle with a feeler gauge but perhaps there's just a tiny little difference beyond that which is making this shuttle both quieter and able to work with the rest of the machine to turn better corners.

It will take wiser heads than mine to know if that might have anything to do with it but thought I'd report it right away (this news is only a few minutes old as I write it).

I'm very keen to hear anyone's ideas on what might have been (or was in fact) the "secret sauce" from changing to another shuttle.

Ta heaps... Megan

MeganMills

Hi Watson - I have an update I've posted in an answer to OurWorkbench you might find interesting. Thanks so much for your ideas. While I don't think the shuttle tension was the problem (I'd got it as close to even top and bottom as I could using my "tension meter" (aka postage scales!) I think you were on to something and the problem was mostly likely under the bed. Kind regards... Megan