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A Real Bad Word Of A Time W/needle Cutting Thread

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Cobra Class 3

207 top & bottom

size 24 needle

I switched from 25 to 24 in order to change the look a bit but since I'm having a lot of trouble with the needle cutting thread on stitch backs at the beginning and end of my stitching. Also having trouble getting the bottom hook to grab the thread to make the knot and the stitch ends up dropping.

Is there a way to get this to work or am I going to have to switch back up to a size 25 needle? This is really :ranting2: me off.

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First of all, change the needle; it might be bent or chipped. Make sure the thread guide channel is on the left and the eye on the right side of the needle. Check the bobbin thread to ensure that it is tight and is not wound around where it shouldn't be wound. Check the top thread path to make sure the thread is going through all guides and tensioners. Sew a few stitches forward, then backward, without any thread. See if the needle goes directly into the previous holes when sewing in reverse. Make sure there is enough top pressure to keep the leather from lifting with the needle, on the upstroke. That will cause skipped stitches and frayed thread.

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Thanks Wizcrafts. I'll recheck everything. Needle is brand spanking new and I'll wind a new bobbin.

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Well now the drop stitches are even more fierce. Still no go. I had to hand walk the machine to get this current order done or else I'd still be there messing with it. This was the 3rd time I restitched this holster :deadsubject:

I was watching in the gap there of the machine - when the top thread drops down and makes the loop that the hook is suppose to catch, it looks like the top loop isn't big enough and the hook just flies right by. What does that mean?

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I was watching in the gap there of the machine - when the top thread drops down and makes the loop that the hook is suppose to catch, it looks like the top loop isn't big enough and the hook just flies right by. What does that mean?

Ah, now we're getting the right info from you!

If the loop at the eye of the needle is too small, the hook will miss it, as you noticed. You have three possible things to adjust to fix this problem.

  1. There is too much top tension. Loosen the bobbin tension to the minimum that still gives a little pressure on the bobbin spring, then loosen the top tension to match. With less top tension the needle should form a bigger loop, as it begins its ascent.
  2. The pickup point is too far from the needle. Move the pickup point a little closer to the needle's eye.
  3. The timing is set to early. After moving the pickup point closer, retard it slightly, to allow the needle to move up a tad more, before the point intercepts the loop. You may have to pick off the loop just above the hole in the needle's eye.

It might be that the thread you are using is too rigid for the leather you are sewing. It may be that the needle is lifting the leather just as it begins to ascend. More top pressure will stop the lifting. Finally, the needle may be to big for your thread. Try going down one more size. If that makes it worse, go up to the next larger needle.

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Ah, now we're getting the right info from you!

If the loop at the eye of the needle is too small, the hook will miss it, as you noticed. You have three possible things to adjust to fix this problem.

  1. There is too much top tension. Loosen the bobbin tension to the minimum that still gives a little pressure on the bobbin spring, then loosen the top tension to match. With less top tension the needle should form a bigger loop, as it begins its ascent.
  2. The pickup point is too far from the needle. Move the pickup point a little closer to the needle's eye.
  3. The timing is set to early. After moving the pickup point closer, retard it slightly, to allow the needle to move up a tad more, before the point intercepts the loop. You may have to pick off the loop just above the hole in the needle's eye.

It might be that the thread you are using is too rigid for the leather you are sewing. It may be that the needle is lifting the leather just as it begins to ascend. More top pressure will stop the lifting. Finally, the needle may be to big for your thread. Try going down one more size. If that makes it worse, go up to the next larger needle.

I thought 'dropping stitches and cutting thread' was a pretty good description of the symptoms.

I don't think the 207 white thread I'm using is too rigid for the 7/8oz Herman Oak. I'm skeptical of the size 24 needle being too big for the 207. As I stated in the first post, I dropped from a size 25 needle on this very same thread and I was having no problems cutting the thread. Though it was dropping a stitch now and then. I'll adjust that top tension. The timing I have begun to suspect too. We'll start there.

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Monica,

I too have a Cobra Class III sewing machine. I have has a few problems with mine as well. What I have discovered, for me anyway, that problems like that are usually something I did. What I usually do is step back, rethink my thread and needle combination, change out needles and re-thread the machine, and sew on some scrap leather until I have the problem figured out. If that doesn't work I do the only thing I can, CALL STEVE!

Good Luck, I feel your pain.

Nick

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I thought 'dropping stitches and cutting thread' was a pretty good description of the symptoms.

I don't think the 207 white thread I'm using is too rigid for the 7/8oz Herman Oak. I'm skeptical of the size 24 needle being too big for the 207. As I stated in the first post, I dropped from a size 25 needle on this very same thread and I was having no problems cutting the thread. Though it was dropping a stitch now and then. I'll adjust that top tension. The timing I have begun to suspect too. We'll start there.

It sure sounds to me like the needle is too far from the shuttle's pickup point, or the timing is too advanced, or both. But, your mentioning that the loop was very small makes me suspect too much top tension, or too big of a hole, from a too big needle. If you downsize your needle it will move even farther from the pickup point.

I had a big Adler flatbed machine for a few weeks and it came equipped with a #200 needle. I bought some #160 needles so I could sew with #138 thread and found that I got constant skipped stitches. I then learned that there is a fixed width spacer screwed onto the inside of the shuttle. That spacer is matched to the needle size and ensures that the point never actually hits the needle. This works fine when both needle and spacer are the same width. But, changing to a narrower needle moves it to the right of the point, which cannot be moved closer due to that spacer block. I was going to gave to buy a thinner spacer to use #160/22 needles, but traded the machine instead. Maybe your machine uses a similar spacer system inside the shuttle?

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I watched the DVD today, still up here matter of fact. I checked that the cams were in correct timing, they were. I checked that the presser feet hit the needle plate at the same time, they didn't. I adjusted them per the dvd instructions. I checked the hook timing. It was slightly behind so I adjusted it, again per the dvd instructions. I pulled the hook out and cleaned everything up in there. I put everything together and hoped things would smooth out. But it didn't. I'm playing with the tension now.

I left the cover off the bobbin so I can watch the things move in there. On the dropped stitches it looks like the fatter part of the hook near the eye pushes the thread out of the way and the tip of the hook can't catch the loop. I'm getting some video clip as soon as I get the battery recharged. I'm wondering if I need to advance the timing a little more so the hook can be consistent.

When did my stitching machine turn into my hot rod? :rofl:

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Well I tried adjusting the hook timing some more to see if I could stumble onto the magic formula but I got nothing. She still drops a stitch. I messed with the tension up and down, top and bottom and I just don't know.

And did you know it's Friday?? I thought it was Thursday. I really need to go on vacation.

:head_hurts_kr:

I'll have to crunch this last order out so I can fall out of the world for a while.

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When did my stitching machine turn into my hot rod? :rofl:

Hey Shorts, I feel your pain. I figured I had gotten interested in Leather working only to find out that I need to be a sewing machine mechanic as well. Being a tool maker would be a good secondary, and don't get me started on honing and grinding!!!

All that said your thread is really helpful, as I have suffered all of these problems, but haven't been able to articulate them well enough to get help on them.

cheers,

'cole

smashcomp.gif

(substitute sewing machine for computer)

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I finally caved and called Steve. He had me lower the needle in the bar about halfway then stitch. So far not dropped stitched. What this did was tell him and me that the hook needs to be brought forward just a little bit more. I'll get that done in a bit.

Overall, glad to know what the problem was. I intentionally held off from calling Steve to see if I could work through the problem. It looks like I was on the right track but stopped just a little bit short.

Back to work...well, not for me yet. I'm going on vacation as soon as I get these orders packed up to ship. Ahhh sweet release - a margarita on the rocks please. :lol:

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Hello to all. To those of you who have a Juki 441 or the Juki 441 clone like the Artisan, Cowboy, Cobra, Ferdco, SewPro, and others, and your machine starts to skip, follow this procedure:

Lower the needle 1/16 of an inch. Just above the needle set screw is a hole that allows you to see the top of the needle. Drop the needle so the hole is half way covered with the top of the needle. Then test on scrap leather. If this solves the problem, then your machine is slightly out of time. If the company that you bought your machine from has done the correct set up of the machine, then you will not need timing devices or spacers to solve this problem. Here is the sequence that you should follow:

1. Make sure that there are no problems with the threading, or any burrs that might be on the point of the hook, or anywhere else. In other words, make sure that all of the normal things are as they should be.

2. Put a new needle in the machine.

3. Set stitch length at zero.

4. Raise presser feet.

5. Remove needle plate so you are able to see the hook.

6. If you are still unable to see the hook after removing needle plate, then remove the feed dog. When putting the feed dog back on, make sure that it is no more that 1/16 of an inch above the needle plate in it's highest position.

7. Turn hand wheel towards you until the needle is in it's lowest position, then continue to turn the hand wheel towards you until the needle comes up 3/16 of an inch. This measurement is critical.

8. At this time, the point of the hook should be even with the needle, and approximately 1/8 of an inch above the eye of the needle.

9. If this is the way your machine is set, then it should sew. If it still does not sew after making sure that all of these adjustments are correct, then you may have to retime your machine.

10. If you need to retime your machine, then do what "Grunt" said: CALL STEVE!

I will help anyone with any of these problems, no matter what machine you own. Thanks, Steve

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