Sewing machine help

[tearghost]

I posted a message asking for help on what machine to buy got that figured out, but in that message I talked a bit the machine I have. So here it is, it's a jack JK-6380. The trouble I'm having is when I start stitching, pictures show my problem. Black thread is my top stitch that lay's flat on the top and the beige thread is my bottom (bobbin). The pic showing the black and beige thread is the top of the leather and the pic with just the beige thread is the bottom. I have never used a sewing machine, please any help I can get is well appreciated. I know it's got something to do with tension but I don't know what controls what and how to adjust the tension.

Thank you in advance for your help.    

[Bugstruck]

Looks like you have little or no bobbin tension but read on, that may not be all going on here. Make sure the bobbin is spinning the correct direction (I think clockwise on yours as viewed from this side you insert the bobbin- when you pull thread) and is engaging beneath the bobbin tension spring fully.

I don't know your machine but I believe your upper thread path may be incorrect. Check this first in your manual or go up to superior sewing, they may have one to download.  That take-up spring is reverse operating to my rotary hook machines. Forgetting that, I don't think the thread should come off the take-up spring (on the lower tension assembly) and dive under that chrome bar to the left before it hits the guide (above the take-up spring). I think it should go from the spring through the small guide above the spring and to the take-up lever (upper arm with hole).

Once you have the upper and lower thread paths sorted out and checked, if it is still doing the same thing, tighten the bobbin tension in small increments, maybe 1/4 turn and see if that helps.

Some other with better knowledge will likely come to assist and advise if I am giving any incorrect information -or- add to what I'm saying.

 

  

 

[tearghost]

6 minutes ago, Bugstruck said:

Looks like you have little or no bobbin tension but read on, that may not be all going on here. Make sure the bobbin is spinning the correct direction (I think clockwise on yours as viewed from this side you insert the bobbin- when you pull thread) and is engaging beneath the bobbin tension spring fully.

I don't know your machine but I believe your upper thread path may be incorrect. Check this first in your manual or go up to superior sewing, they may have one to download.  That take-up spring is reverse operating to my rotary hook machines. Forgetting that, I don't think the thread should come off the take-up spring (on the lower tension assembly) and dive under that chrome bar to the left before it hits the guide (above the take-up spring). I think it should go from the spring through the small guide above the spring and to the take-up lever (upper arm with hole).

Once you have the upper and lower thread paths sorted out and checked, if it is still doing the same thing, tighten the bobbin tension in small increments, maybe 1/4 turn and see if that helps.

Some other with better knowledge will likely come to assist and advise if I am giving any incorrect information -or- add to what I'm saying.

 

  

 

I will have to try this. Thank you

[Constabulary]

try a needle 1 size up or bottom thread one size smaller.

[kgg]

Hi tearghost,

It does look like a tension problem. I think the your machine is very similar to the Juki du-1181n, so I think if you go to the Youtube video titled " Industrial Walking Foot - Juki DU-1181N" by Phillip Miller it should help you figure out your tension problem.

Keith

 

 

 

[Bugstruck]

9 minutes ago, Constabulary said:

try a needle 1 size up or bottom thread one size smaller.

Thought that for a moment too. I does look like he's already down a thread size on the bottom. Guessing 138 and 92 but can't tell, maybe 92 and 69. I zoomed that fist photo and the needle looks adequate size to the thread but worth a check. He's not fraying or busting thread at least. Time will tell it and you guys will get him there.

[brmax]

It looks like the top top tensioner is way tight, with that I truly dont understand yet the bottom tensioner/ take-up. 

Im interested on that assembly fore sure. 

Good luck

Floyd

[Bugstruck]

7 minutes ago, brmax said:

It looks like the top top tensioner is way tight, with that I truly dont understand yet the bottom tensioner/ take-up. 

Im interested on that assembly fore sure. 

Good luck

Floyd

Tearghost,

Floydd is correct that does look tight but it may or may not be. A very rough test is (once you know the thread paths are good) pull the thread out of the needle and pull on it, straight down with the presser foot lowered (that engages the primary tension discs). Should feel tension-wise about what it would take to pull a fully loaded coffee mug across a reasonably smooth wood table top (not formica). Get it there, re-thread and try that as a start point for upper tension. It is impossible for us to observe and know your tensions. It is a feel thing or a load gauge thing if you are as technical as some. Feel works good enough. Bobbing tension should feel much less. Maybe like an empty coffee mug on formica.    

[Bugstruck]

Tearghost,

From what I just observed I now believe your upper tread path below that chrome bar is correct, so disregard my prior comment. Stay with that path.  

[SARK9]

3 hours ago, brmax said:

It looks like the top top tensioner is way tight, with that I truly dont understand yet the bottom tensioner/ take-up. 

Agreed. The main upper tension spring's coils are fully compressed, we can't tell what loading is also being contributed by the upper pre-tensioner above it.  The thread looks completely taut running into the first guide before the pre-tensioner, with no hint of a normal catenary curve.  Check for a snag coming off your thread cone, or a loop on or under anything. Back off the main tension to a looser "starting point" and observe the results. Good luck!

-DC