Chinese cobble machine breaking the thread.

[climent]

My new Chinese cobble machine keeps breaking/snapping the thread as seen in the following video:

https://www.youtube.com/watch?v=YqigqC8Igrw

Any help on how to fix this problem is appreciated.

Thanks!

[Wizcrafts]

Check the needle and the hook for burrs. Wrapping the thread around the sharp toothed foot is asking for broken thread!

[kgg]

I agree with Wiz and as side note which way are turning the handwheel. You should be turning it clockwise and a good reference video would be https://www.youtube.com/watch?v=LOliY3NHg_A to help visually understanding how the Chinese patcher forms the basic lock stitch.

kgg

[chrisash]

How much tension do you have on the bobbin

[dikman]

I don't see any bobbin thread?

[climent]

I went back to the workshop and started looking at how it should behave. I realized the needle was not going all the way down and decided to move the pipe that holds the needle an 8th of an inch down so that when the needle moves a bit up to create the thread loop that the bobbin shuttle hook catches, the needle hole is about at the bottom of the bobbin. Now it works fine.

 

Thanks for all the comments.

[climent]

To explain with a bit more detail what was happening:

the cobbler came with one of the pieces broken, the one that connects the arm that's in front of the machine with the needle arm (pictured). The seller sent a replacement, but it was shorter. With the new piece in place, it changed the height at which the needle rests, so when the loop is created for the hook to grab through, the thread end that pulls through the needle's eye was pulling upwards and the bobbin case was pressing it against the wall. The spacing between the walls and the bobbin case is so tight that the thread is essentially cut.

Again, thanks for the help!

Edited June 26, 2019 by climent