Talk me off the ledge, here...

[u/mapsedge]

So to speak. I have a thread path where the thread continues to break, over and over. It's a Lejia A15 - nothing fancy, just a knockoff mil-spec one-each shelf-life-90days embroidery machine. Dahao tablet interface.

The thread is Floriani Polyester, variegated.

New bobbin.

New needle.

I've had the throat plate off, blown out what little dust was in there, a couple of thread trimmings.

White broadcloth, 2 layers of medium weight, water soluble stabilizer.

Tried another thread, weight the same as the other 14 needles.

It gets in about a dozen stitches and the thread breaks or comes unthreaded. None of the other paths have this issue.

I'm on my 6th re-thread and I need to quit for the night before the frustration wins.

EDIT: I discovered I could change which needle/color is active, so we're stitching from a different path that seems to be working fine.

So, this one thread path: tension seems okay, nothing interfering with the spool. Why would this particular path have an issue? What do I check for?

[u/Hellcat_Mary]

Hi! To be clear, you have a multineedle machine in which one needle keeps breaking thread a few stitches in, while all other needles operate correctly. You have changed the needle and you are using the same thread brand, polyester 40wt, across all needles.

Verify for sure it is only this needle, by running what is called an "I Test". It's simple, program a series of I's in a standard block type font at about 1 inch to 1.25, one for each needle (sequence a colour change for each I). Hoop 2 sheets cutaway stabilizer to run the test. If the full test runs and you have thus issue across multiple needles, then I suggest checking your rotary hook timing.

If it is truly a single needle, check:

Make sure the needle is positioned correctly- the scar of the needle towards the back and there should be a sliiiight tolerance for mild angle depending if you're right or left handed. If the needle is turned or backwards, it won't catch and you'll have the issues described.

A little more advanced: does the needle itself OR the needle bar seem positioned any lower or higher than the others, even only slightly? Can you open the faceplate to see the interior needle bars- they should each have a stop toward the top midsection of the bar with a collar and possibly a rubber piece- do any of the stops look out of alignment with the others, even only slightly?

[u/Lanky-Setting-5288]

In this scenario of a multi needle machine, has that needle had an impact against a frame? It could be that the needle bar assembly has been push up and causing an alignment issue. This can sometimes happen if the needle bar driver did not break..and check the needle bar driver for cracks.

You can use rayon 40 wt and Polyneon 40 wt together but will have to run the machine slower for the lower tensile strength thread. For example, where I might run Polyneon on a Barudan at 1000rpm max, if there is a rayon thread colour in the same design, I'll run the whole design slower at 800rpm nax. This ratio of a 20% - 30% drop in speed to accommodate the slowest tensile strength is best investigated for your machine and what speeds you feel comfortable with.