Massive Thread Issue..highlead Gc22618-8B...help

[caba]

Can anyone please help...have a highlead GC22618-8B....it was sewing well with a T40 thread....put a T20 on it with a 2.5mm hide.......it was fine for an interior pocket on a tote.....I had also fiddled with presser foot cos it was marking hide with two layers of this hide...then I went to overstitch one layer of the hide, and hey presto ...jamming.every time...the thread is coming up back through the walking foot as well as bunching underneath!,, any ideas..I have cleaned bobbin casing...rethreaded and oiled it....it seems to be picking up bobbin thread fine...renewed and double checked needle....even gone back to thinner thread..still doing the same! Is it tension or timing...excuse the metric , Im in Australia..best Regards

[Constabulary]

Have you checked the needle bar hight and hook / needle timing?

[caba]

Not the needle bar height , no.....will check it out in the morning.....its bringing the bobbin thread up, so timing mustnt be too bad.....did read slight retard of the timing can cause thread issues......will gear up for some fiddling tomorrow......thanks Constabulary

[SARK9]

>>I had also fiddled with presser foot cos it was marking hide with two layers of this hide...then I went to overstitch one layer of the hide, and hey presto ...jamming.every time.<<

If you lightened the foot pressure for 2 layers, it may be marginal for only one. See if the work is lifting/shifting on the upstroke, or maybe increase the foot pressure again to eliminate that as a variable.

-DC

[Wizcrafts]

Make sure that the top thread is not lifting up from the center of the top tension disks. Twisty thread tends to do that. Compensate by threading through holes in a guide ahead of the top tension disks.

Also, ensure that you are passing the top thread around the check spring. Failure to thread it will cause thread problems.

The travel of the check spring must be long enough to keep the thread taut until the needle pierces the top of the material. Then, it must stop before BDC to allow the needle to form a thread loop at the ascending eye of the needle.

[caba]

Thanks everyone.I feel very lucky to be receiving terrific help so quickly......its a bleakish rainy Sunday here today...perfect time to work this thing out!....this thick thread is very springy....and the presser foot was definetly tampered with by myself in haste , so thanks all..will let you know tonight if Ive prevailed...I have a comission job to do ...

[caba]

Ugh..what a day!.......ended up being all that was suggested!...the upper thread tension was so loose and the uptake spring wasnt working properly.......the jamming caused the feed dog to loosen slightly.....caused needle issues.......skipped the timing ....also the pressure foot was seriously too light.........now its sewing after many hours and a capable other half......I m so appreciative of the skillful people that have helped me Thanks..I now have that bit more know how bout this machine....am going to buy new feed dog and needle plate and then new walking foot....thanks guys