jfhspike

Just in case anyone else ever needs this: it's M10 x 1.00 (i.e., extra-fine thread). Also, the threads only extend about 3/8" or 1/2" into the crankshaft.

I've got a Bernina 217. I'm trying to add a needle positioner. The adapter that is held to the crankshaft just beyond the handwheel came with two screws (One looks like M8; the other is a little smaller), one of which is supposed to fix into the threads in the end of hte crankshaft. But my Bernina appears to use an M10 screw. My problem is the thread-pitch. I've tried M10 - 1.50 and M10 - 1.25 and neither wants to go in (although the 1.25 seemed promising for about 3/4 turn or so). Does anyone know whether it's actually an M10-1.00 (which is "extra fine" in metric terms) or perhaps some custom thread. Any advice eagerly accepted. --John

Thanks, folks. I do a lot of zig-zag sewing -- thread costs less than my time, and I make enough errors that the ease of removing zig-zag stitching is of real value still. Also, zig-zag tends to not "bunch up" the cloth as much as does straight-stitch, when I'm working with few or lighter layers. For making a dodger...I'll use mostly straight stitching, and for the cloth-only parts, I'll probably use the Bernina (or Adler if I buy it); for the parts that involve strataglass, or vinyl-plus-sunbrella assemblies (e.g., handhold areas) ... well, that's a really good place for the Juki and its walking foot. I sure wish I had the Juki-with-reverse, but having picked up this one, with table!, for $60, it's hard to let it go. I'll mull over the Adler for a little longer keeping thoughts of what you've said in mind. --John

I've got a Bernina 217 that I like a lot. My sewing is mostly sails, canvas covers for boats, and things like 'dodgers' (http://www.shipshapecanvas.com/canvas_dodgers.php) which involve sewing through both thick plastic and multiple layers of Sunbrella. What's not great is that the foot pressure is (somewhat) limited, and the bobbin is small. For really substantial jobs I'll haul out a Juki 562 (with no reverse) that I picked up amazingly cheap...but it's straight-stitch only, and has no reverse. I've got a chance to get an Adler 98-2-8. It's not a walking foot, which would be nice, but otherwise looks like a beefier machine than the Bernina, and at least one place I read said that it had a really strong feed, which would be great. I'd probably sell the Bernina if I got the Adler. Any thoughts? (Availability of parts? Quality of the machine? Suitability for these kinds of tasks?) Thanks in advance.

I've got a Bernina 217 that I got from a friend who could never get it to sew right, and I'm now starting to work my way through the "adjuster's manual" to try to get it working a bit better (and doing some cleaning, oiling, etc. along the way). The manual says things like "The needle must enter the middle of the stitch hold see from front-to-back" (i.e., it should be the same distance from the "feed" side, or "operator side" as it is from the "exit side"). I understand what this means, and how to adjust it, but what I don't know is the tolerance: should I be making these distances match with feeler gauges or a micrometer depth gauge or calipers, and worrying about .001" adjustments, or is .01", which I can see with a good eyeballing, good enough? (It's pretty obvious that something is terribly wrong with at least the bobbin/hook timing adjustment, because when I set the needle to far-left, it hits the bobbin case rather than slipping down into the cutaway part the way that it's supposed to. But right now I'm at a step 1, which is the needle stitch-hole adjustments). Once again, thanks in advance for any advice you have. My new dinghy spritsail will appreciate it.

Thanks for the suggestions. The problem is sadly not the lack of hollow grind on the blades, but really a matter of angle (and the oval-head shape of the adjusting screw, which compounds the problem). I think I'll make myself one of those cutoff-mini-drivers I was describing and see how it works out...

I have a Juki 562 with a bobbin-case that's captive (i.e., you have to undo a screw or two to remove the case). That makes adjusting the lower tension a pain...except that if I move the hook to the right position, I can see the lower-tension-adjusting screws, and can reach them with a jeweler's screwdriver...at an angle, because the screwdriver has to come down into the bobbin-case area from above. And that angle makes the adjustment a pain in the neck. Does everyone in the world except me have a "sawed-off jeweler's screwidriver" for situations like this? Or is there a proper tool for this job and I just don't know about it? (I'm thinking that about 3/4" of screwdriver blade, with the back 1/4" wrapped in adhesive tape to give me something to grip...that might just about do the job, since not a lot of torque is required.) Thanks in advance for suggestions (perhaps including "You're supposed to take the case out to adjust that, you idiot!")

Thanks for the suggestions, everyone. I tried a different needle (no effect), checked for burrs (none), and then noticed that the problem only happened when I was going fast. At "half-clutch" speed, things worked fine for many many inches of stitching. I figured it HAD to be a hook/loop issue. When I looked at the hook closely, it turned out to be about .04 or 0.5" from the needle. You couldn't quite drive a truck through there, but close. I adjusted the hook position to be a good deal closer, and things now seem to be fine. I would have checked sooner, but seeing the hook/needle position is harder on this machine than my old 31-15, so I never really checked closely. D'oh!

I'm sewing 4-6 layers of cloth-backed vinyl with a Juki LU-563, V-92 thread, #18 needle, about 6 stitches to the inch. It's mostly going fine, but every 20 inches or so, I get a problem (as shown in the image below): the thread bunches up above the eye of the needle. I suspect that either (i) the hook is sometimes catching only half the thread, essentially splitting it into two strands; one breaks, the other continues to work as usual, and the broken one is bunching up, or (ii) something else is causing one strand to break -- perhaps excessive tension or something. Anyone have thoughts about what might be causing this problem, and how I might address it? I've wondered if part of the problem might be the "stickiness/slipperiness" of the vinyl, perhaps making it fail to hold the thread down enough as the needle's withdrawn to form a proper loop for the hook to grab. If that's the problem, should I try a larger needle? Smaller? Voodoo? Thanks in advance for any suggestions you might have.

Thanks. That photo looks just like what I do, although I use jeweler's screwdrivers instead of the eye-glass ones. Glad to know I'm not along. (Thanks to Stanly, too, for the "there's no right answer here" answer regarding good tension -- gives me confidence that my eyeballing is about right.)

Hi. I've got a two questions about tension adjustment. 1. I know how to adjust things so that the upper and lower tensions are about equal, so that the knot is buried in the material. But there are many ways for two things to be equal: the upper and lower tension can both be large, or both be small. Is there some rule of thumb about how much tension to put on the bobbin (and then match with the upper tension)? Clearly for light fabrics like silk, too much tension will make puckers between stitches, but I'm working mostly with sunbrella, and there's a pretty wide range of tensions that I can put in and still have things work. 2. I'm using a Juki LU-563, with a horizontal bobbin. When you change bobbins, you just lift out the bobbin, not the whole case assembly like you do on some machines. I switch back and forth among threads from V69 to V207; that requires adjusting the bobbin tension, which seems to be placed so that no reasonable screwdriver can get to it comfortably. Does someone make jeweler's screwdrivers with a right-angle bend in them or something? Or does everyone else just swear at their machines like me? Thanks in advance for any advice. -John

Hi, blue99. Look really closely at what happens during stitch formation. There are two things going on. (OK, there are a million things going on, but let's concetrate on two of them). (1) The needle is plunging down through the material, pulling up a bit to form a bulge, which the "hook" is catching and wrapping over the bobbin, forming the "knot", and then rising up to pull the knot -- both the "top" and "bobbin" halves of the knot -- up into the midpoint of the material (at least if you've got things set up right). (2) The cloth is being advanced by the feed dogs, so that the knot you've just formed is now pressed between the feed dogs and the plate beneath it. That holds tension on the "already sewn" part of the two threads so that the needle/tension and bobbin/tension assemblies can get the right tension in the next knot. Imagine if part 2 happens too early -- before the needle and the up-and-down-arm that's above it have pulled the knot into the cloth, the material has already advanced. You end up with a loop of top-thread dangling below the cloth, and pinched between the foot and plate. The arm rises up but cannot pull that loop back up tight, and instead pulls more thread through the upper tension assembly. If you think about this, you'd expect the problem to be worst with long stitches. With short stitches, the previous knot isn't really all the way under the presser foot as described in item 2 above. (This is what I found on MY machine; if you don't have these symptoms, then I doubt my solution is the one to follow!) So I'd try the following: back off on the stitch length until you're making quite small stitches and see if the loops still appear on the bottom side. If not, then with small cloth-advance, you're good, but with large cloth-advance, you're getting the pinching I described. You might even want to try the small cloth advance and see whether you can adjust the tension to something reasonable in that situation. What you need to do, IN THIS CASE ONLY -- i.e., only if the "small stitches" situation doesn't make loops and lets you use more reasonable tension, but long stitches make you get loops -- is to adjust the timing of the feed-advance vs the needle/hook operation. How do you do that? None of the manuals I found described that, so I'll make an attempt here. Look at page 4 of http://parts.singerco.com/IPinstManuals/31-20.pdf; there's a cover plate marked "F" in Figure 3. If you look behind that cover plate, you'll see that the main crankshaft of the machine is visible. Two things are driven by that crankshaft at that end, and ONE of them drives the feed-dog assembly. Look at the diagrams at http://parts.singerco.com/IPpartCharts/31-15.pdf Find the page saying 22303-1/3 at the right. There's a screw marked 446AL; if you loosen that, the feed eccentric (127152) can be rotated on the crankshaft by a few degrees, adjusting the timing of the feed. Which way do you rotate to advance or retard the feed? I have no idea. I did it by trial and error. I want to be clear here: adjusting this is what I did to make my machine work, but I'm NOT a sewing machine service person -- just an amateur kind of mechanically inclined guy. It's pretty clear to me that adjusting this eccentric too far can really screw things up, and trying to make the adjustment through that cover-plate hole isn't easy. If I were you, I'd be very certain to mark the initial position of the eccentric so that you can put it back to its former state, and try adjusting it by only quite small amounts to see if you can improve matters. The fact that adjusting this eccentric is not included in the general manuals suggests to me, at least, that you're messing with the Dark Arts, and are more likely to screw things up than fix them. I'd never have done it to mine if it weren't essentially a machine that I could afford to destroy (I only paid $50 for it). Anyhow, with that caveat, and with a clear understanding of what I've written above, you could try what I'd described, and it if works for you, let us know. Or you could take the safer route and have a professional adjust it for you. By the way, when you adjust that screw, make sure to use a screwdriver that fits really well -- wide enough for the slot, thick enough to fill the slot but not so thick that it won't go in --- and make sure to snug it up decently when you're done. You'd hate to have the feed adjust itself during your later sewing.

Thanks for the suggestion, Merlyn616. As it turned out, it was a top-end timing problem for me, but there's probably someday going to be someone else reading this thread of postings for whom your answer is exactly what's needed. I'll keep in mind the idea of adjusting the tension rotation as a possible fix for future problems. --J

Exactly -- it was that comment that got me thinking, and I looked around and couldn't find any information about how to adjust this "top end timing," so I went with the "maybe it should work like other machines" approach. Thanks again for steering me right. -John

SUCCESS! After careful side-by-side comparison of the 31-15 and my Pfaff 140, I decided that the timing of the feed dogs really WAS wrong on the Singer. Basically, the material was done feeding by the time the thread-take-up lever reached the top. That meant that the stitch I was trying to tighten was already "buried" under the presser-foot, and things just weren't working. By contrast, on the Pfaff the feed dogs were at top dead center just about the time the take-up lever reached its top position. So, after carefully marking the current position of the feed-dog cam (which was pretty easy: the grease on the main shaft was a perfect medium in which to draw a "line" with a small awl), I went ahead and retarded the feed by about 30-40 degrees. Result? Perfection! The stitches look like real stitches, I can reduce the tension by about 2 turns from where it had been, and I can even tighten up the bobbin tension a little without any adverse effects. And when I stitch that sailcloth, it looks like a sailmaker did it rather than a bozo Part of my reason for being willing to mess with the feed timing is that it was clear that it had been messed with relatively recently (less accumulated grease there than on other nearby areas of the machine, and a slightly bunged-up screw-slot was a further clue. I would not, in general, recommend that anyone with a machine that's worth real $$$ try this. I only did it because my machine cost just $50, and I figured I didn't have much to lose. Thanks again to everyone for helping talk me through this. You guys helped me figure out that if I just reasoned about it hard enough, I'd get somewhere. --John