Continuing our lively discussion from the other day, Babette wrote:
After working in a technical school, I think I’ve seen all the ways a machine can be misthreaded. One popular one was to put the bobbin in back to front so that the thread comes off at the wrong direction. Often the machine will appear to sew ok from the top thread but a huge knot of thread forms underneath and eventually it breaks.
I could never remember how to feed the bobbin into the case correctly, until someone (a home sewer) taught me that the bobbin and thread hanging off should form a “9” when feeding it into the case. I remember her every time I set a bobbin into a case.
I would also like to share a discovery I made, which seems counterintuitive, on the surface: I found that, often, if I’m dealing with a heavy fabric, with several layers, I’m better off using a smaller needle than usual. Yes, that’s right; instead of taking a great big needle and trying to hammer it through multiple layers of denim or canvas, sometimes it’s actually easier for a smaller needle to slide through the fabric; it’s pretty amazing to watch (especially after you’ve snapped a few size 18 needles). It’s also helpful to take a nice solid hammer to the seam allowance, before stitching – but of course, that’s not a practical manufacturing procedure! (Or at least, I don’t think it would be. It can be a dandy help at home, however.)
Interesting about the smaller needle. About the hammering though; if you work with a lot of layers or heavy goods, hammering is the way to go. While hammering may not be common in the typical plant, if you work in a leather or coat sewing place, you’ll hear whack whack whack all day long. It gets to be rather comforting. As I said before:
Sewing hammers are great for sewing! How many times have you tried to sew through too many layers and the needle will fight you and you end up with skipped stitches? Well, you give it a good whack (or two). Ever have trouble joining a four way seam? Well, hammer it before you sew and the ease of sewing will amaze you. Have problems top stitching pocket corners? Give it a whack. Sewing hammers are a great solution if you don’t have a walking foot and just need occasional seam compression.
In this entry you can see a picture of mine. John says you can buy them at Polsteins for $19.95. My last suggestion for preventing skipped stitches is silicone spray. I love this stuff.
I can see using a smaller needle for thick layers possibly working. Rather, I think the difference is a sharp versus a ballpoint needle. As Kathleen states, you need the right type of needle for the fabric. Generally speaking, a ballpoint is for knits, sharp for a woven.
The issue of using the wrong needle point is common too. As Esther says, ballpoints are for knits and often silks and the like. These push the threads aside. Sharp points will cut threads. Still, sometimes cutting is desirable. If you’re sewing leather, you do want cuts which is why leather needles have diamond or triangular shaped points. Speaking of Solinger’s book from yesterday, here’s a chart from his book on page 197 that describes the different shapes of points.
You may find this chart on needle nomenclature from page 195 useful too.
Speaking of charts, this one on Organ’s site may be useful. Rest your cursor over the different parts of the needle to get a pop up with more details and variations. Another site is Great Western Sewing Machine (scroll down) because it includes something nobody’s mentioned yet, that being the importance of the throat plate. There you’ll also find a complete needle size chart.
I note that the entire topic of presser feet has been neatly avoided… I’m tempted to say we should leave it that way. I think that needles, thread, presser feet and throat plates are at the top of my list of things I least like writing or talking about. It’s like homework for me so I really appreciate all those tips you’ve left in comments. I had a friend who -was otherwise quite charming- loved to talk about this stuff. I wonder if we can scare Troy out of retirement. He hosted our weekend long marathon manufacturing boot-camps. He had a big contract facility in nowhere Missouri. They always fed us good. I miss those days.
The “9” is an excellent illustration of loading a bobbin. Much better than what I was taught. In all my classes it was pounded into our heads to: ‘waterfall to the right’.
I agree with the throatplate assessment. Some machines also have a needlebar clamp (I know my 20U does) which prevents zig zag motion of the needlebar. While the zig motion does not break threads, directly, the miniscule zig motion and needle deflection could cause burrs on the straight-stitch throatplate, which eventually cut bobbin threads.
Silicone spray makes me a little sketchy. I would be concerned for gunking up the bobbin and hook assembly. For chainstitch and coverstitch machines, I prefer to use thread lubricant on the thread after it passes out of the tension assembly. This little bit of lubricant also reduces needle deflection.
There’s a product called ‘Sewer’s Aid’ which is a home-market version of the commercially available thread lubricant. Because of how the instructions are written, it wreaks havoc on household machines from the thread tension assembly, to the feed dogs, and the bobbin/hook assembly. I’ve heard too many mechanics cussing up a blue streak to consider using it.
The Pegasus and the Yamata industrial coverstitch machines have a reservoir that the thread glides over to pick up lubricant just before passing into the needle(s). In contrast, domestic machines do not have this feature. To use ‘Sewer’s Aid’ correctly, the directions should be ammended to read: apply a drop to the thread, after it exits the take up mechanism, about 1 1/2 inches in front of the needle eye every few stitches.
> … the bobbin and the thread should form a 9 when feeding it in the case
My (commercial) Bernina 217 is an exception to this rule. The bobbin rotates away from the thread take-out through the tensioner, so its figure would be a 5. Odd, not seen that on other machines I’ve used.
Good post, Kathleen. Stashed it all in my burgeoning doc file.
probably a bobbin case without anti-backlash springs. The 6/9 clockwise rotation when installed is sometimes reversed in bobbins without an anti-backlash spring.
thanks for continuing to give me a little technical background! I feel like a cowboy stitcher in comparison to all the technical knowledge you routinely toss off.
I don’t remember where I first learned how to refer to the direction of bobbin insertion (the dealer?) as either a “p” or a “q” but I find that it’s very handy and students remember it well. I tell them, “You are a q” or “You are a p.” Often they’ll write it down in their manual. There are quite a few “p” machines out there, especially machines that have “drop in” bobbins.
In my experience with industrial and home machines with bobbin casings – If you load the casing into the machine from the back the bobbin unwinds counterclockwise or a “p”. If you load the casing into the machine from the front or the side the bobbin unwinds clockwise or a “q”.
I don’t know if this is universal but I have figured out what was “broken” on several machines at my college several years ago by loading the bobbin “backwards” into the casing and finding that the machines then worked just fine.
I just bought a Bernina 1300 cover stitch machine. The right needle is always coming unthreaded. What am I doing wrong. I have changed needles and adjusted settings. It was sewing fine on thinner fabric but with the thicker , no go. Help!
you’re the best!
In my experience as maintenance engineer working on industrial free-stitch, hemming and auto-sew machines for a large garment company, skipped stitches have always been a product of improper timing resulting from improper needle bar depth settings or hook assembly/shuttle timing. I have never seen an improperly threaded machine skip stitches(and Ive seen improperly threaded machines almost daily). Normally when a machine is not threaded properly,it will only affect thread tension and sewing quality. Most of the time it has resulted in a lowering of top thread tension and causes top thread to bubble underneath. I have yet to see a free-stitch or float-sew machine such as juki 8700-7 skip stitches. Every time I have a machine skipping stitches it is an AMS(automatic sew) machine such as Juki 220ENhl or 215D or 220C and it is always a needle height/hook shuttle timing issue. The first thing to do when a machine is skipping stitches imo is to replace the needle and recheck needle-bar height and hook/shuttle timing.