Sewing Machine Not Picking Up Bottom Thread When Back Stitching..ideas?

[joppstack]

I have an Adler 205-370 which I have used for years with great results. Lately when I am sewing heavy leather.. 1/2" plus, and I get to the end and reverse to back stitch it is not picking up the bottom thread. It sews fine going forward and does fine on leather not so heavy. I have checked the timing and it is good. Any ideas? Thanks...Neil

[Wizcrafts]

When sewing thick stacks of leather, timing becomes much more critical. The hook arrives at a different place in reverse than in forward. My guess is the it arrives sooner and your loop has not fully formed yet. Try retarding the timing a few degrees.

Another thing to verify is the height of the needle bar. If for any reason at all the needle bar has been pushed upward, your timing will be off.

You can try rotating the needle slightly to aim the loop towards the oncoming hook. That means turn it to towards the back on the right-eye side.

Thick leather and previous stitches will deflect the needle. A deflected needle is either closer or farther away from the scarf above the eye than when setup with no material.

The check spring travel may need to be dinked with to keep the top thread under tension longer.

[joppstack]

Thanks for the reply Wiz... you have some great ideas. I am starting to think it may be the check spring. This machine I have had since new and it is about 16 yrs old now and has the original check spring. I have another one of the same machine that is much newer and the check spring seems much stiffer than on the older machine. Is there a way to adjust the tension of the spring or do I need to just find a new one and replace it. It seems like it would be pretty simple to change it out from the way it looks... Thanks again for your insight...Neil

[Wizcrafts]

I don't have a 205, but did have a 204-374 for a while. I seem to recall that the check spring was mounted onto a split threaded shaft that can be loosened and turned one way or the other. One direction tightens the spring. You should be able to find that out. Give it enough spring action to keep the thread under tension. Then set the bottom stop to control the travel for well placed knots.

Check springs can be too loose or too tight for a given size and stiffness of thread. An overly tight spring can actually override your top tension adjustment, or at least add to it. I try to balance mine to work well with #138 thread, without overriding the top tensioner too much. It then works fine with #207 and #277. #346 might need more spring action though. I have to loosen the spring to use #92 thread.

I hope this helps.

[Troy Burch]

Wiz, I was wondering If it makes a difference where the needle is located when the machine is switched to reverse, and does the machine have to stop before changing directions? Thanks Troy