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LeatherandHyde

Cobra Class 26 problem

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I received my new class 26 machine yesterday and have been spending the last 2 days setting it up and experimenting with it, but am finding some problems with it. 
 
I set up per instructions and watched several videos on YouTube so I don’t believe the error is in my end. 
 
I am able to run a length of stitching for about 10-14 inches before the knot pulls through the top then again the machine will run 10 inches or so then the knots pull through leaving an inconsistent stitching patten I have adjusted the tension on the front on the machine many times to try and fix the problem but it does not seem to help. 
 
Is there something I need to do or look at differently? 
 
Ps leather is English bridle and Latigo 8/9oz and 10/11oz.  
 
 

Thanks

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You might have overly twisty thread that is wrapping around itself, or around guide posts, suddenly increasing the top tension. Or, the thread may be poorly wound on the spool. Or, the thread coming from the spool may be caught under other windings causing uneven tension off the spool.

If your machine has a top mounted thread guide post with holes on the top and then about an inch below, try wrapping the thread through the top, then counterclockwise around to the bottom hole and out. This will counteract any excessive clockwise coiling from the spool.

It's also possible that the bobbin thread is jumping out of the tension spring because of how it was wound, or due to coiling. Pull out a few feet of bobbin thread and get a feel for the smoothness and evenness of the pull. If it seems to lift out of the spring, pull out the bobbin and reverse its direction of feed.

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4 hours ago, Wizcrafts said:

Or, the thread may be poorly wound on the spool.

This sounds familiar. 

One particular brand of thread I once used ( here in Oz) was so tightly wound on the spool, it was  causing all sorts of tension issues. I had to manually unwind the thread  off the spool for a few metres or so,  or enough for each job to loosen it up,  and then wind it back on by hand before I could start sewing. 

Needless to say I no longer use 'that' thread  again. 

HS

Edited by Handstitched

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Thanks for the thoughts. I’ll give this a shot and see what happens! As you’d imagine it’s pretty annoying as I can’t complete an item with out it being ruined. 

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I still have a couple of spools of black thread that are so coily that I feed them up from the floor to the thread stand guides, then do my counterclockwise wrap around the top post holes. Without these countermeasures the thread would be useless and it cost a lot of money when I bought it.

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23 hours ago, LeatherandHyde said:

Thanks for the thoughts. I’ll give this a shot and see what happens! As you’d imagine it’s pretty annoying as I can’t complete an item with out it being ruined. 

Hey LeatherandHyde,

     I was forced to buy the class 26 earlier this year,(long story), but from the start I have had nothing but problems with it. First, the walking and presser foots leave deep impressions in the leather was the first one, second is the missing a stitch problem like you have noted. I buy the Tandy brand, 138, and 207. I seemed to notice it does a better stitch with my 138 size but still not 100% perfect. But 207 it is very inconsistent.  I use white thread and you can really see it bad.  If you find out the problem please let me know. 

    By the way, the tension is off on top all the way out, called leather company and dude told me to cut the springs down 5cm. Still nothing has worked. Im been told to hammer the stitches and leather, was told to use different harder leather, etc. 

     Now I just dont care, but my missing threads is pissing me off now. Im gonna see if tension discs are clogged or maybe buy didnt brand thread. please let me know if you find anything that works

DF9C450A-A869-4525-9A1E-CC8D94EF3C52.jpeg

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On 8/2/2022 at 8:34 PM, LeatherandHyde said:
I received my new class 26 machine yesterday and have been spending the last 2 days setting it up and experimenting with it, but am finding some problems with it. 
 
I set up per instructions and watched several videos on YouTube so I don’t believe the error is in my end. 
 
I am able to run a length of stitching for about 10-14 inches before the knot pulls through the top then again the machine will run 10 inches or so then the knots pull through leaving an inconsistent stitching patten I have adjusted the tension on the front on the machine many times to try and fix the problem but it does not seem to help. 
 
Is there something I need to do or look at differently? 
 
Ps leather is English bridle and Latigo 8/9oz and 10/11oz.  
 
 

Thanks

I’ve also got a 26, but I’m not sure if I can help.  Can you give some more information, i.e. stitch length setting, thread weight, where you got the thread from.  Also, how are you winding the thread through the tension post at the top of the machine (chrome post with holes)?  I think @Wizcrafts is on the right track with thinking it’s a thread tension problem. 

Here are a couple of manuals that may help.  Before trying any of the fixes in the Engineer’s Manual I’d try different thread, usually the simplest answer is the correct answer. 

Juki_LS-341N_Engineers_Manual.pdf

Juki LS-341N InstructionManual.pdf

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On 8/3/2022 at 1:34 AM, LeatherandHyde said:

I received my new class 26 machine yesterday and have been spending the last 2 days setting it up and experimenting with it, but am finding some problems with it. 

The quality of thread can play an important part in any stitch as well as the needle. You didn't mention what size of needle you are using. If the your needle is poor quality / damaged or incorrect size for the thread and or the thickness of material you are going have problems. If the quality of the thread is poor then you are going to have problems.

I would check the following chart as a starting point in selecting a needle for a particular thread size. Example: V138 needs a #22 or 23 needle but in thick / sticky material you may have to move up to a #24 needle. I think your Class 26 is a clone of the older Juki LS-341 who rated their machine for a #24 needle for V138 in thick materials not what size of thread can fit through the eye of the needle.

www.tolindsewmach.com/thread-chart.html

I would replace the needle and replace the spool of thread with a brand name products like Schmetz needles and A&E thread both of which can be had from companies like wawak.com.

Also note that there have been a lot of problems associated with the 8 ounces size spools of no name brand sewing thread.

kgg

 

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On 8/4/2022 at 7:50 AM, AtomicLeathers said:

Hey LeatherandHyde,

     I was forced to buy the class 26 earlier this year,(long story), but from the start I have had nothing but problems with it. First, the walking and presser foots leave deep impressions in the leather was the first one, second is the missing a stitch problem like you have noted. I buy the Tandy brand, 138, and 207. I seemed to notice it does a better stitch with my 138 size but still not 100% perfect. But 207 it is very inconsistent.  I use white thread and you can really see it bad.  If you find out the problem please let me know. 

    By the way, the tension is off on top all the way out, called leather company and dude told me to cut the springs down 5cm. Still nothing has worked. Im been told to hammer the stitches and leather, was told to use different harder leather, etc. 

     Now I just dont care, but my missing threads is pissing me off now. Im gonna see if tension discs are clogged or maybe buy didnt brand thread. please let me know if you find anything that works

DF9C450A-A869-4525-9A1E-CC8D94EF3C52.jpeg

Still no luck…..

 

im using the needles provided with the machine and thread that is sold by leather machine company.  Trying both 138 and 207. I’m having the same problems you describe. I have been using a glass slicker to rub out the walking foot marks which works good.  When the thread pulls through that is not something I can sell. At this point I am pretty disappointed. 

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On 8/4/2022 at 9:08 AM, Tequila said:

I’ve also got a 26, but I’m not sure if I can help.  Can you give some more information, i.e. stitch length setting, thread weight, where you got the thread from.  Also, how are you winding the thread through the tension post at the top of the machine (chrome post with holes)?  I think @Wizcrafts is on the right track with thinking it’s a thread tension problem. 

Here are a couple of manuals that may help.  Before trying any of the fixes in the Engineer’s Manual I’d try different thread, usually the simplest answer is the correct answer. 

Juki_LS-341N_Engineers_Manual.pdf 738.97 kB · 0 downloads

Juki LS-341N InstructionManual.pdf 653.29 kB · 1 download

Stitch length is 2mm have used both 138 and 207. The thread is from leather machine company. Not sure of the brand though, it is what they supply. I have the thread going through the 2nd hole down which is straight on from the thread feeding it. Still trying things but still encountering knot pull through. 
 

it’s almost like it doesn’t matter how thick the material is. It still pulls through. The tension is super loose at this point. Very bizarre. 
 

‘’I appreciate everyone’s responses as I work through this. 

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This is my set up using 207 thread from Leather Machine Co.  Have you tried contacting LMC and explain what’s going on?  When I first got mine they were very helpful when I through the machine out of time. 

 

103DB9B6-22B3-4A55-9710-6C475EBAA134.thumb.jpeg.00b3103cd17acc98f984ad774d3acd95.jpeg

2CFAD422-9CC3-4B7E-9BCA-7846D8A359A7.thumb.jpeg.81c4352f02f95d25026f8514283e6192.jpeg

 

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Here’s a quick stitch guide I made with 207 thread through 6-8 oz leather, the numbers are relative to the numbers on the stitch length knob

CB052625-7C2D-4545-AFD0-0B7F5B8733F2.thumb.jpeg.1287010f87d61389ee104a0d71d45010.jpeg

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