Drop Stitch

[Scary Leatherworks]

Well I finally got my Cobra lass 4 this week and have already called steve a few times with questions. I have been having trouble with thread tension (mainly my fault) but there is no tutorial on how to get it back to where it should be. Ensuring the tension knobs are turned together is all I can find. To late for that so how do you get back to proper adjustment?

Also I changed to the strap plate for a trial and changed back but since I changed back the machine has been dropping stitches. sometimes it's as often as every 5th and sometimes not til the 10th or 20th stitch. The needle comes up and the leather comes up off the machine as well. I have increased the foot pressure (didn't help) changed the needle (thought it helped but still does it) and slowed the machine way down. It didn't do it until I removed the bobbin and feed dog to change the plate.

Any suggestions would be great.

[Kcinnick]

I just went through the new machine thing also... so I am not an expert here by any means, but when I was skipping stitches I had the thread from the bobbin fed through incorrectly and it was putting way to much tension on the bobbin thread. Once I figured that out the machine hasn't skipped for me.

[Big G]

had the same problem with mine , lifting leather, problem was tension and i oiled the machine as well. tension is easy to mess up and hard to get back i found out. i bought cheap bellies at tandy and cut into strips. quite a few went flying into the corner of my basement before i got the tension right. i decided i was going to get it right without bothering steve, probably a mistake but i learned a little. i had to readjust the timing several times and was afraid to tighten allen bolt too tight , but since i really cranked down on it it has stayed in time

[dirtclod]

The way i was told to set tension was to sew on 2 pieces chap leather. Try it and see what it looks like if it's still messed up back the tension off ( all the way sometimes ) and see what happens if it's still messed up just tighten a little at a time till you have it right. Most of time that i have had a problem it was because the tension was to tight.

As far as the leather picking up do you have a wax pot ? If you do put some thread lube in it that should help for most leather but i have got some leather that the needle just sticks in, If it's really bad i just sew without any thread around the piece and then thread it and sew the piece. It's a PITA but better than messing up your piece.

[Scary Leatherworks]

Thanks for the advice. I'll mess with my tension and check my timing. As for lubrication I am using some scraps of W&C show harness, since I'm going to be sewing a bag soon, and it's really quite oily so I wouldn't think that's the problem but maybe it is. I'll have to see if I can find the oil spot in by the bobbin. I've oiled everything else except there.

[rickybobby]

Oiling the bobbin area is pretty easy. There are no "oil holes" so just a couple drops in the track area for the bobbin shuttle should do it.

Rick

[Go2Tex]

Thanks for the advice. I'll mess with my tension and check my timing. As for lubrication I am using some scraps of W&C show harness, since I'm going to be sewing a bag soon, and it's really quite oily so I wouldn't think that's the problem but maybe it is. I'll have to see if I can find the oil spot in by the bobbin. I've oiled everything else except there.

I had the same problem with some thick harness sticking to my needle and lifting. Try some veg tan. It will also happen if you try to stitch wet leather.

[amuckart]

What sort of outer foot are you using?

[Scary Leatherworks]

What sort of outer foot are you using?

I'm using the one that can be used for bullet loops single foot on the left side of the needle

[Wizcrafts]

A single toe foot exerts less hold-down than a double toe foot. A narrow foot also exerts less pressure than a wide foot. When sewing very dense leather, try to use the widest presser foot/feet you have for your machine. If this means you have to reposition your edge guide ahead of the outer foot, do so. Spread the top pressure out over as wide a path as possible, to keep the leather from lifting with the needle.

[Luke Hatley]

A single toe foot exerts less hold-down than a double toe foot. A narrow foot also exerts less pressure than a wide foot. When sewing very dense leather, try to use the widest presser foot/feet you have for your machine. If this means you have to reposition your edge guide ahead of the outer foot, do so. Spread the top pressure out over as wide a path as possible, to keep the leather from lifting with the needle.

THIS HAS TO BE THE BEST INFORMATION THAT I HAVE HEARD TODAY.THANK YOU...

[mmirob]

I am having the same problem with mine. I never adjusted anything and it just started doing that. So frustrating when sewing a belt then having to back. I notice that it misses the stitch when it lifts the leather. I am sewing two 8oz veg tanned. I need to call Steve unless he chimes in here.

[Wizcrafts]

I am having the same problem with mine. I never adjusted anything and it just started doing that. So frustrating when sewing a belt then having to back. I notice that it misses the stitch when it lifts the leather. I am sewing two 8oz veg tanned. I need to call Steve unless he chimes in here.

Dropped stitches are often caused by lifting of the leather, as you are experiencing. The solution is simple: increase the top spring pressure! If your machine is a walking foot machine, and if it has two top springs for the two feet, see if the inside foot has an adjuster for its spring and tighten it down as well.

If you adjust the foot pressure springs all the way down and the leather still lifts with the needle, your only recourse is to either use a smaller needle, or a wider presser foot (set) (or run the top thread through silicon or oil lube in a lube pot).

Edited November 25, 2011 by Wizcrafts

[mmirob]

Dropped stitches are often caused by lifting of the leather, as you are experiencing. The solution is simple: increase the top spring pressure! If your machine is a walking foot machine, and if it has two top springs for the two feet, see if the inside foot has an adjuster for its spring and tighten it down as well.

If you adjust the foot pressure springs all the way down and the leather still lifts with the needle, your only recourse is to either use a smaller needle, or a wider presser foot (set) (or run the top thread through silicon or oil lube in a lube pot).

Thanks Wiz, I always appreciate your expertise here. I have the cobra class 4. Sewing with #25 on 277 top, 207 bobbin. I do know that it does have at least one top spring pressure knob...not sure if it has two??? As mentioned by many, the operators manual on these machines are quite lacking. Leather Machine Co should do several Youtube vids addressing many of these common adjustments, timing etc I am sure it would helps Steve's phone from ringing off the hook. Tippman actually has one of the best user manuals IMHO. Will try your suggestions immediately.

Wiz, when do you know to replace needles? Could a dulling needle also be a tell tale culprit?

Best,

Rob

[MADMAX22]

Yeah the chinese manual is crap. Ryan included a kind of manual basically a bunch of pictures and a few instructions which has been very helpful when I started. The chinese manual is only decent for finding parts incase you need to order something.

[Art]

Max is right about those Chinese manuals written in Chinglish. It is a good idea when buying Chinese machines to buy one that is a good clone of something common, by a known maker. For the 441 clones, it is not hard to find a Juki manual that is written in pretty good English. For Pfaff clones, the German manuals are pretty good in about three languages, including English. Singer clones have manuals up the wazoo, and so forth and so forth. Following the above practice also provides parts availability, both OEM and aftermarket.

Art

Yeah the chinese manual is crap. Ryan included a kind of manual basically a bunch of pictures and a few instructions which has been very helpful when I started. The chinese manual is only decent for finding parts incase you need to order something.

[Scary Leatherworks]

I wanted to say thanks to all that responded here it made for a good bit of learning. I was at my wits end with my new machine trying to get it working right again. When I got it, it worked fine but I wanted to try out all the plates and feet and somehow I got it out of time, although I still don't know how. I followed the directions on the DVD from Steve to re-time but still couldn't get it to not skip stitches. I emailed Steve the other day (I had already talked with him once) and he called me as soon as he got it. We had a long chat and he went into much better detail about timing the machine. I do agree that he would decrease his phone calls if he had some in-depth videos (although he is very pleasant on the phone) the timing is very tricky if you have no idea about it. For starters I wasn't raising the needle to the exact height just guesstimating. then the shuttle has that 1/4 play in it (clock/counter-clock wise) and I wasn't sure if the hook should be at the needle all the way clockwise or counter0clockwise. (does this even make sense it's confusing and difficult to explain)

Anyway I have it fixed and Steve was great and patient with my dumbness.

also I noticed mmirob is using #25 needles and 277 thread. I'm using #24 needles and 277 thread. Does this matter?

[lws380]

I was getting a few dropped stitches on my machine too. I realized how it happened. I notice one day the needle was not centered in the slot for the strap plate. So I centered it by loosening the plate and centering it for the needle. Then it started dropping stitches, but only a few. I read the manual and it said the needle has to be close to the left of the slot in the plate. Actually it says the width of a business card, which is not much.

So I loosened the plate and moved so that the needle was within a business card from the left of the slot in the plate. That is while standing in front of the machine looking down like you are ready to sew. One I moved it back as indicated dropped stitches went away.