Thread break at each trim

[promocanuck]

Hi, I've been trucking away on a job on my Amaya XT but all of a sudden in the past hour or so I'm getting a thread break every time there is a trim done. It almost seems as though it's not trimming right as the thread jumps right up. Very frustrating; any ideas?

Thanks!
Promocanuck
p.s. same job running on my other machine and *knock on wood* it's fine...

[Judy]

Hi there. My XT does the same thing just before it's time for the 600,000 stitch hook lube....

[HERB]

I have had some success with this by moving the tie-off location slightly. Also changing the tie-off type may work. The selector is not picking up the top thread, because of this, when it trims the thread is not being captured and held properly. This causes your issue, what we call "springboarding.

[promocanuck]

Hi Herb,

Sounds like a good theory but if it's a problem with the design, why does it work on one machine and not the other? - to test this I tried another design on the machine and it is cutting properly...HOWEVER I notice now that the bobbin does not seem to be trimming through the whole design. Perhaps this is contributing to the problem also?

Thanks
PC

[HERB]

It is not really a design problem. It has to do more with how everything is positioned at the time of the trim. There is a triangle of thread that forms and the selector needs to grab the thread and pull it back under a spring to hold it in place after the trim. The selector is missing the top/bottom or both and when the knife hits the thread it will springboard up (top thread) or give a short bobbin tail. Moving the tie off changes things slightly and "SOMETIMES" helps.