Pfaff 335 w/ 135 Thread Having Tension Issues

[dikman]

I just read the title more carefully - 135 thread (doh! me dummy!). I had problems with my old 335 when I first tried 138 thread (it worked fine with 69), it was dropping stitches and causing fraying due to the hook snagging the twists in the thread. I had to tweak the position of the hook saddle (can't think what it's called at the moment, the bit holding the shuttle assembly). I found it was pretty fussy adjusting it so that the hook would catch the thread correctly. Also the thread tension take-up spring (the one mounted on the tension discs) needed tweaking a bit.

The photo also suggests to me that a bigger needle may help.

[RockyAussie]

I still think the thread looks wrong but is it possible to post a close up pic of the feet and in particular the dog foot. I am curious about the relief slot for the bobbin thread to follow and position in. I did a major improvement once by hollowing out more for the thicker thread and angling a bit at the same time.Just a thought if the next size down thread in bobbin is out of the question. Also is it a Tri or LR needle? If it is a round point you have no hope.

[drawingonblank]

1 hour ago, RockyAussie said:

I still think the thread looks wrong but is it possible to post a close up pic of the feet and in particular the dog foot. I am curious about the relief slot for the bobbin thread to follow and position in. I did a major improvement once by hollowing out more for the thicker thread and angling a bit at the same time.Just a thought if the next size down thread in bobbin is out of the question. Also is it a Tri or LR needle? If it is a round point you have no hope.

 

[RockyAussie]

OK , I have not seen before the curly thread thing on the bobbin case so I dug in around the back of a 40' shipping container and took some somewhat dark pics on one I haven't used in a good while.  By the dog foot I mean the foot with the groove in it as I have pictured in the 2nd pic. Just also check your back foot is coming down level with the base as you may not be getting the pressure down right as the needle is lifting out.Your picture looks like it is angled high at the front.

[dikman]

That little curly piggy-tail is certainly....different. I'm curious as to its function.

[SARK9]

My original Singer 20U33 bobbin cases have that as well....

 

-DC

 

[dikman]

Son-of-a-gun, so there isn't anything new under the Sun . So, what does it do?

Edited December 21, 2016 by dikman

[Northmount]

That guide on the bobbin case is for doing zig-zag stitching.  My Singer 20U instructions indicate it can be bypassed for straight stitching.

Tom

Edit:  On the Singer 20U, the face of the bobbin case is parallel with the arm, not 90 degrees like the Pfaff, so this comment isn't really relevant to the Pfaff.  More likely to aid timing when changing stitch lengths and the motion of the walking foot.

[spenzher]

Have you tried using different thread for the top thread? I had some thread once that would twist right before it got picked up by the hook and would make an extra big twisty knot. This made the knot impossible to be pulled up onto the needle hole, resulting in loose stitches and was indicating loose top tension. I wonder because I see some stitches look crooked like mine were. I switched to a different spool and the problem went away. 

I'd try using a different spool (still sticking with 138) and see what happens. 

Edited December 22, 2016 by spenzher

[sorefingers76]

Having a issue with a 335 yanimita I know that's not the correct spelling but any way I'm getting bunching skip stitches and thread breakage.  But just on back sticking. Sews heat with number 69 thread I believe I'm using 135 thread and number 20 needles. For the larger thread. It'd like when I back stitch through the previous stich it affects the tension of the top thread like resistance wise. I make a bunch of leather bags and hats . But primarily leather and I have a tipman boss and I know sewing tooling leather and dryer leathers are way different than sewing chrome tan oily leathers. With a machine. I had a old Adler shoe patcher and it didn't bunch on a back stitch. If it bunched it done it all the time same as the boss. This is a new one for me any suggestions . Thanks