Stitching cutting into material

[Teres]

Hi,

I have a Jack H2 not an ideal machine but i was recommended it and I'm still not entirely sure.

Anyway I'm trying to sew biothane for dog leads and I've had many issues so far but by looking at old threads I've managed to sort these out. I am using a size 24 needle and tex 135 bonded nylon both top and bobbin. I am using the larger needle size as i couldnt get the knot to sit in the middle of the biothane and that has fixed it.

My current problem is when I try sew 3 layers the top thread will cut into the biothane material but the bottom i can generally get a decent stitch. I have tried adjusting the tenssion in various ways assuming I'd have to loosen up and it does improve slightly but then i start getting loose thread at the bottom.

Would someone be able to advise me how I can fix the thread cutting into the material? and perhaps get a nice consistent stitching on both sides? 

The pictures:

The black piece is probably the best I can get it fit both sides - mind my messy work (still trying to get the hang of it)

The blue material is me trying to play around with tensions and obviously not getting anywhere but you can clearly see the thread burying into the material.

 

Thanks!

 

[Wizcrafts]

Perhaps you can reduce the tension and travel of the check spring to loosen the lay of the stitches. They call it a thread take-up spring in the manual. Here is a link to page 11 where the adjustments are outlined (in Chinese and English). In essence, the spring movement only needs to continue until the needle pierces the top of the material. If you setup the machine for thin material, the spring may be holding on way too long. If there is a second adjustment for the amount of slack thread, increase that amount. The actual spring tension will need to be fairly strong for #207 thread.

IHTH

[Beanwood]

Please post if you try Wiz's idea - I'm interested to see how you get on with remedying this. I've not had too much success with sewing Biothane either - the same issue as you have, and interestingly also with the H2. 

I have a similar issue sewing other materials on my bartack machine - the thread doesn't pull into the materail, but it can make a REALLY tight knot, so 'squashing' the multiple layers. I hadn't considered the check spring adjustment.

[Teres]

 

On 5/17/2023 at 3:08 PM, Wizcrafts said:

Perhaps you can reduce the tension and travel of the check spring to loosen the lay of the stitches. They call it a thread take-up spring in the manual. Here is a link to page 11 where the adjustments are outlined (in Chinese and English). In essence, the spring movement only needs to continue until the needle pierces the top of the material. If you setup the machine for thin material, the spring may be holding on way too long. If there is a second adjustment for the amount of slack thread, increase that amount. The actual spring tension will need to be fairly strong for #207 thread.

IHTH

Thank you for the suggestion Wiz. 

I spent a few too many hours trying to work out the instructions unsuccessfully, I cant seem to find screws/part shown and listed in the instructions. for example the thread tension adjusting seat screw (A) I cannot find -  I can see the seat but its tucked behind the metal body. Do you have a better interpretation than i do of those instructions based on the pictures I've attached?

Im new to sewing machines so Im not entirely sure what Im doing. I did some trial and error adjustment based on guessing but i couldn't get any different results so i reversed what i did out of fear of messing too much. 

Thanks.

[Teres]

On 5/17/2023 at 3:28 PM, Beanwood said:

Please post if you try Wiz's idea - I'm interested to see how you get on with remedying this. I've not had too much success with sewing Biothane either - the same issue as you have, and interestingly also with the H2. 

I have a similar issue sewing other materials on my bartack machine - the thread doesn't pull into the materail, but it can make a REALLY tight knot, so 'squashing' the multiple layers. I hadn't considered the check spring adjustment.

Will update you how i get on.

I get tight but acceptable (not that I'm pleased with) knots with 2-3 layers of standard beta biothane like you describe, my issue is with sewing multiple layers of superheavy but I'm sure a solution would help both to get a nicer stitch.