Cb4500 tension

[Parott1]

I've been using #138 thread on my Biothane Beta dog leashes, but recently tried going to 277 top & 207 bottom; per Biothane's recommendation.  I can't for the life of me get the knot to pull to the center.  It's at the halfway to 2/3's on the bottom piece.  Anytime I back tack, the bottom looks like crap because the knots aren't pulling up and are all jumbled up on the bottom.  

 

The machine is threaded correctly and the thread is ran through a lube pot.  I tightened the side and top tensioners exactly how Ryan Neal shows in his YouTube videos.  I've also tried to tighten and loosen the bobbin tension to no avail.

Does anyone have any suggestions?

[MADMAX22]

Try 1 larger size needle. 

[Parott1]

I'm using a size 26 needle

[JerseyFirefighter]

Im sorry I cannot add to assisting you as my suggestion would have been the bigger needle as well... however would you mind sharing any good biothane distributors? I've been meaning to get some pieces and mess around with it. 

[Wizcrafts]

Biothane is wicked. Not only do you need to use a larger needle, but you also need to tighten the top tension, or loosen the bobbin spring. Also, not estableshed, but try using a non-leather point needle. This stuff is made of vinyl, which is usually sewn with a round/sharp point, not a leather point. A compromise would be a tri-point needle.

[Parott1]

I'm using a 794S size 26.  How I have the top tension pretty tight.  How tight should the bobbin tension be in comparison to the top tension?  

I had 277 on the top and accidentally had 138 on the bottom. The knots were pulling right into the center.  When I went up to 207 no matter what I did, the knots wouldn't budge

[MADMAX22]

Yeah the S needles dont do as great for thick leather or other tough materials IMHO. 

[Parott1]

What kind of needle should I be using? 

[Parott1]

I finally got the knots to pull through to the center, but they are inconsistent. Some stitches has the knot pulling to the upper piece of beta and other stitches have the knot more towards the bottom.  Could this be caused by loose bobbin tension?

[MADMAX22]

55 minutes ago, Parott1 said:

What kind of needle should I be using? 

 

1 hour ago, Wizcrafts said:

Biothane is wicked. Not only do you need to use a larger needle, but you also need to tighten the top tension, or loosen the bobbin spring. Also, not estableshed, but try using a non-leather point needle. This stuff is made of vinyl, which is usually sewn with a round/sharp point, not a leather point. A compromise would be a tri-point needle.