Stitch unbalanced every few stitches

[the deacon]

ok, moved up to an #18 needle and still had the same issue. Then did 4 layers of the #10 duck and that worked much better, if I look closely (and into the needle hole) I can see the knot favoring the top side. This doesn't solve the problem as my work only calls for 2 layers.

No knots or twisting happening through the thread guides or off the spool

this one is stumping me.

[Yetibelle]

I suspect the bobbin tension is off, could be you need a new bobbin-case-spring?  It may look correct, but just not have the right pressure on the thread anymore?  If you can load some pictures of your bobbin and case and hook, maybe someone will notice something?

 

[Wizcrafts]

2 hours ago, the deacon said:

ok, moved up to an #18 needle and still had the same issue. Then did 4 layers of the #10 duck and that worked much better, if I look closely (and into the needle hole) I can see the knot favoring the top side. This doesn't solve the problem as my work only calls for 2 layers.

No knots or twisting happening through the thread guides or off the spool

this one is stumping me.

Try reducing the tension or travel of the check spring. Consult your manual for how to do this, or Google it.

[Colt W Knight]

Had this problem with my consew 206, turned out the tension discs had worn a groove.  Took them apart and polished the groove away with s Drexel and buffing rouge . Problems went away.  I ordered a replacement tension setup, and half the psrts were unusable (Didn't  fit), so I ended up piecing stuff together to replace all the worn out parts

[Matt S]

@the deaconForgive me if I'm pointing out the obvious but have you tried with a fresh bobbin? I have found that unevenly wound bobbins can cause these sort of inconsistent tension issues and they aren't always visible once the bobbin has been filled.

[Bugstruck]

As someone mentioned that can occur with ballistic nylon but that is largely fabric driven and duck does have some cavity to it bit I haven't experienced it with that other than very limited/rare. I'd say bobbin or bobbin tension to start and I would be inclined to tighten it up to start (if that doesn't bunch the fabric) and then go opposite if that doesn't help. If that didn't improve things then I'd eye the top thread action below the needle plate as possible. A top thread intermittently catching or hook timing on the edge of right can cause some variance with how that top thread snaps up on pull. I assume you aren't novice enough to put the bobbin in backwards like someone I am. Fought a stitch balance isse for half an hour one evening before I figured that one out??? Plain stupid. Work back towards the spool from there. I also assume you are having the problem across multiple fabrics. Punching holes one size over the recommended needle size is rarely but sometimes revealing too. Helped balance the stitch on that ballistic material.

[Bugstruck]

Forgot to second Wiz's comment on the check spring. Seating as the needle enters the fabric. Then tension.