I am an art quilter that purchased a 440 about 9 months ago because I wanted the BSR. I'm having a real problem using the invisible and metallic thread with the BSR - the thread breaks. When I asked the dealer about it, I was told the interior of the Berninas get very warm because the gears are all metal. The metal heats up, the thread stretches and then breaks. She suggested I take frequent breaks if I want to use the invisible or metallic thread so the machine can cool down. Is anyone else having this issue? I used the Sulky invisible and metallic thread almost exclusively on my Janome with no problems. This is very frustrating. Any help would really be appreciated.

I used invisible thread on my Bernina Aurora 430 without a problem. The brand I used is YLI. Another option would be Superior Monopoly. Since it's polyester, it shouldn't "melt," even though I don't think that's the problem.

I would check the thread path and make sure the thread isn't hanging up somewhere - sometimes it can get caught on the spool. I had a spool of Sulky, and it seemed prone to tangling up, so a thread net might be useful.

Janet

Might be a burr somewhere. Also, this was recently discussed on one of the Bernina yahoo groups. You could search recent posts or the archives. I wish I remembered the specific recommendations, some of which were to use Sewer's Aid and to position the spool differently. I rarely use those threads, so I wasn't paying full attention.

do you have speed control? i found when i slowed down the thread did not break so much- and finding a better brand/fiber is a +
make sure you are using a needle for metallics makes a difference too.

I had problems with metallic thread and it turned out to be because I was using the wrong needle!
Sewing at a slower speed helped too.

what needle are you using.makes all the difference!

a needle for metallic thread helps also > I use a topstitch needle with a big eye.