Cobra Class 4 issue

[RMB Custom Leather]

[RMB Custom Leather]

No idea why it wouldn't let me type a post along with attach the video but anyway.  Been having issues with my class 4 off/on for a while.  It often times skips stitches, has loops on top, and loops on the bottom all spastic.  Now it is getting all bunched up and binding up from what appears to be the bottom or bobbin assembly.  Have no idea what to do really I have adjusted the top tension and the bottom via the small screws on the bobbin.  I have also tried to adjust the timing.  The needle is installed correctly.  Can anyone suggest anything else to check or give me some feedback after watching the short video of what it is doing?  
 

5 minutes ago, RMB Custom Leather said:

IMG_2735.MOV

No idea why it wouldn't let me type a post along with attach the video but anyway.  Been having issues with my class 4 off/on for a while.  It often times skips stitches, has loops on top, and loops on the bottom all spastic.  Now it is getting all bunched up and binding up from what appears to be the bottom or bobbin assembly.  Have no idea what to do really I have adjusted the top tension and the bottom via the small screws on the bobbin.  I have also tried to adjust the timing.  The needle is installed correctly.  Can anyone suggest anything else to check or give me some feedback after watching the short video of what it is doing?  

[Hildebrand]

Did you recently re thread it?  I had that exact balling up of the top thread once when I missed the take up lever in the re threading process.

Todd

[RMB Custom Leather]

1 minute ago, Hildebrand said:

Did you recently re thread it?  I had that exact balling up of the top thread once when I missed the take up lever in the re threading process.

Todd

Yes but I re threaded it a couple of times just to make sure I didn't forget something.  

[Constabulary]

poor video sorry...  too many thread hanging around and I cannot see what the actual top thread is and it is to fast to see the sewing cycle. Can you hand crank the machine (take off the V-belt) and watch the sewing cycle?

when you start sewing do you hold the thread for the first 2 or 3 stitches? W/O knowing your machine and how it is threaded but this could happen when you loose the top tension (probably incorrectly threaded / wrong thread path?)

Edited May 29, 2019 by Constabulary

[RMB Custom Leather]

44 minutes ago, Constabulary said:

poor video sorry...  too many thread hanging around and I cannot see what the actual top thread is and it is to fast to see the sewing cycle. Can you hand crank the machine (take off the V-belt) and watch the sewing cycle?

when you start sewing do you hold the thread for the first 2 or 3 stitches? W/O knowing your machine and how it is threaded but this could happen when you loose the top tension (probably incorrectly threaded / wrong thread path?)

Yea I will post a longer better video.  Yes I do hold it for the first 2 or 3 stitches.  The top tension has been a pain since I have had the machine not sure.   My class 3 that I had ran smooth the whole 5 years I had it this machine not so much.  

[JLSleather]

Tough to tell anything with that booger ball goin' on in there.  First thing I would do is pop out the shuttle/race thingajiggy.. clean that out behind there.  Very possibly git some 'stuff' or a piece of broken off thread in behind all that, which can cause that binding.  And if it binds, and you don't stop... ugghhhhh ..

[kgg]

What I would do is go back to basis. Start from scratch remove all thread, top and bobbin. Re-thread top, re-thread another bobbin, check to see if there is something amiss in or around the bobbin case, install a new needle of the correct size for the thread size and reinstall the bobbin making sure the thread is coming off in the right direction. Then hand wheel through and see what happens.

3 hours ago, RMB Custom Leather said:

Yes but I re threaded it a couple of times just to make sure I didn't forget something.

From your post I get the impression that you are completely removing the top thread before installing new / different thread, if so why? Even through I don't own this type of machine, when I change thread on my Juki 1541S because of size, type, colour or running out for the top thread I just lock the presser foot up to release the tension on the top thread tensioner, cut the thread at the old spool, tie the end of the old thread to the end of the new spool thread, hall the thread out of the needle and pull the end of the old thread dangling alongside the needle, install a new needle if necessary and thread needle. Basically, once I threaded the machine correctly I haven't needed to go over the thread path since.

kgg 

[RMB Custom Leather]

I will keep trying stuff, it has been very inconsistent the whole time I have had it.  Wish I would have kept my class 3 now even thought it shouldn't matter.  I am sure it's just an adjustment issue. Thanks for all the suggestions!

[Hildebrand]

Another thought.  Check the tension disc on the bobbin.  I was battling my CB 4500 tension issues, it seemed like no matter what I did the knot would not change position.  Then one day a felt a little click when I was checking the bobbin thread and from what I can tell the the little pressure disc was in a bind and no matter what I was doing with the screws the actual tension was not changing.  Since then I can make small adjustments and the knot moves as it should into the leather.

Todd

[Lobo]

Here is a thought for you: try calling Cobra Steve and the gang at Leather Machine Company. Couple of times I ran into a glitch with my Cobra Class 4 there was always someone happy to walk me through it to a happy solution.

[jimi]

I would loosen the front 2 screws of the race ring very slightly to see if this stops the thread from jamming.

[JLSleather]

On 5/29/2019 at 6:10 PM, Hildebrand said:

Another thought.  Check the tension disc on the bobbin.

If you have it tightened down, you should feel pressure on teh thread just pulling it with your fingers, without even putting it in the machine.  If you don't, or if tightening it doesn't make the tension greater, then you may have "sprung" the tension spring (on the bobbin assembly).  Simple fix -- Bob (link below) able to cure that for me quickly.