Bad Turns On Adler 67 Gk373

[Scott W]

I have an Adler 67 GK373. I'm using 138 thread top and bottom with 134-35LR size 21 needle. I'm sewing 6-7 oz vegetable tanned leather. Everything works fine until it is time to turn. Normally you would turn the work with the needle down but when I do that the bobbin thread ends up pulling through on the surface. So I have been running a number of tests trying to figure out why this is. It is probably worth mentioning that when I lift my foot there is not an automatic tension release on this machine. It has a thumb tension release lever.

So here is what appears to be happening. The feed dog has a groove running in line with the direction of the sewing. It also has serrated teeth on each side of that groove. When I stop with the needle down and release the foot, the leather stays down snug against the feed dog. In fact the feed dog is in its highest position at this point and sets proud of the needle plate. When I turn the leather the bobbin thread hangs up on the feed dog serrations and a little bit gets pulled out of the bobbin, thereby changing the tension on the bottom thread for the next stich.

So my work around is to turn work just after the needle has excited the leather. There is tension on the top and bottom, because the stich is being pulled tight. When I lift the foot the leather is a hair breadth above the foot dog because of the tension of the upper and lower threads. And also the thread is directly inline with the feed dog hole, so when I turn the work it doesn't catch. This is slower and my first stitch after the turns varies ever so slightly in length, but I don't get the knot pulling through to the top of the work.

So I was wondering, if anybody else has had this problem and if there were different type of feed dogs that I should be looking into? In fact I woul appreciate any suggestion for the type of foot, feed dog, and needle plate I should be using to sew 1/4 inch thick leather for holsters.

Thanks.Scott

[Trox]

Hello Scott,

This is a adjustment issue.

The feed dog highest position should be in level with the needle plate. (The teeth of the feed dog should be in the same level as the needle plate, not over it). You can get manuals and support on this class on sew24.com ” the world of Dürkopp Adler parts” You ca read about your machine and ask questions to Mr. Thomas Brinkhoff, head of spare parts business Dürkopp Adler AG.

He runs the blog there and is very helpful.

Anyway, the 67`s leather subclasses (like yours) are all set up with a lowered feed dog adjustment. Together with a smooth vibrating and feeding foot the needle do most of the feeding job. This way the machine will not mark up your leather during sewing. You must also check the needle hook timing when you at it, and distance hook to needle (With the right needle size). Down load service manual in sew24.com. I think adjusting the feed dog height will take care of your ”bad turn” problem.

http://sew24.blogspot.no/p/downloads.html

Good luck

Trox