Tension Problems - Check the Easy Things First

[garypl]

So I switched thread in my CB4500 from 207 to 346.  Installed new needle and sewed a test piece.  Would not pull knots up into the workpiece, so I started adjusting top and bottom tensions.  Nothing seemed to improve the problem.  Bobbin thread very hard to pull out even with bobbin tension screw turned several turns out.  Played around with adjustments for 20 minutes and no improvement.

Finally decided that the bobbin looked pretty full, so I took it out and stripped off about 5 feet of thread.  Reinstalled the bobbin and thread came out nice and easy!  Too much thread on the bobbin was causing binding.

Restarted from the beginning and adjusted top and bottom tensions and sewed perfectly.

Moral of the story - save time and aggravation and check the easy items first before making big adjustments to your machine!

[LumpenDoodle2]

Been there, done that.....     it’s so easy to forget to check the simple stuff, and dive into faffing about with tension/timing/whatever.

A timely reminder.

[Matt S]

I went "there" this week. A normally very reliable sewing machine (that I rely on) started having tension problems and skipping stitches after a needle change. Couldn't balance TKT20/V138 thread reliably in 4mm/10oz of leather, which is ridiculous. Knot was either not being pulled up into the seam, or a single click of the tension knob upwards and it was sticking out the top.

Rethreaded, nothing. Fresh bobbin, nothing. Changed needle thread, nothing. About time it had a service anyway so I retimed the hook (which was a few degrees off) and the synchroniser while I was at it, still got problems with tension. Stripped out the hook assembly, gave it a thorough clean, inspection and reassembly, whereupon I lost the bobbin tension spring retaining screw while removing the spring to clean under it. Two hours on the floor sifting through the sweepings came to nought. Luckily I keep a backup machine so I transplanted the missing screw, put it all back together and still had the same problem. Then something went "twang" in my brain. Yep, I'd not fully seated the needle when changing it out.

Needless to say the machine worked just fine once I'd pushed the needle fully up into the needle bar and reset the hook timing. Only 6 hours' production time lost to a schoolboy error... 

[Bert51]

I think this is a lesson we all learn the hard way, I did in my early days of sewing.

I thought I would be clever and get as much thread as possible in the bobbin only to find as you did that the bobbin will jam or be hard to turn and stuff up all you tensions.

It does not matter which bobbin I fill now, I only fill them to about 90% of capacity.

Bert.

[shoepatcher]

Bobbins should never be filled over about 85%.  A totally filled bobbin will cause problems.

glenn