My old Durkopp is driving me up the wall!

[toxo]

Good shout Mike. It is a German (metric) machine. Just thought the part might be available. I should have something if it is.

[mikesc]

If the head on a bolt would get in the way..use a piece of threaded bar..cut it "flush" to depth before fitting..then cut a screw slot across the diameter of the bar..to make a "grub screw"..I'd make it from a piece of "stainless" IIWY, cutting the slot will be a bit awkward, but if you use a Dremel with a disc to cut it, life will be easier..there are some dome head bolts in stainless with a hex or torx inset in the dome..those would be ideal..but to get just one or a few, try a custom motor cycle shop..they use a lot of "aeronautic grade" bolts and screws..But you do want stainless steel not aluminium, and brass would be too soft to get it back out easily after a while..

[toxo]

Thanks again Mike. All good advice. Just hope it's just a clamping thing and nothing complicated in there. Haven't sorted it yet cos postman brought presents today. Servo motor now fitted and working cept clipping the cables up. Will go up in a bit to change the tension unit and then let the thing beat me up some more. I'm enjoying the learning tough. Softly softly catchee monkey.

[toxo]

I'm seriously getting fed up now. New servo motor. new tension unit. tried every combination of needle sizes from 90 to 140 with 20/40/60 bonded thread. sharpened the hook and timed with zero stitch set. And still shredding  thread and skipping stitches. I can only take so much and I have to walk away and do something else. But the grey matter still processes and I've just had an idea. The shredding seems to be happening below the needle plate. Now I've just looked at this picture of my cobbled together thread guide just above the needle and I'm thinking the angle of the thread is wrong. With a decent amount of tension maybe it's not only shredding the thread but might it not also pull the needle resulting in missed stitches? Will investigate and inform.

[mikesc]

If your "thread guide" is what I can see at the top of the small image you posted, ( semi circle of bent wire ) then it is certainly not helping the stitch to form..
The thread needs to be much closer in to the needle..it must be in the groove on the left side of the needle as the needle is moving through the leather ( both up and down ) the thread should be touching the needle in that groove almost all the way along it..

[Constabulary]

No offense but you should have posted more detailed pictures of your machine from the start so we probably could have seen if something is wrong on the machine. Seeing the "whole picture" can lead to faster and better evaluations / solutions.

The Singer 111 needle bar works on your 239. College Sewing has them

https://www.college-sewing.co.uk/store/240498-NEEDLE-BAR-SINGER-COMPLETE

If you replace the whole bar you already know where you can find spare thread guides or screws if you need them in the future. Better order a few spare needle screws too. If you loose them on a carpet you never find them again - guess how I know! See items description for spare parts numbers.

Thread shredding often is caused by needle / hook timing issues. sometimes it helps lowering or rising the needle bar just a tiny bit - even when you followed the values from the manual.

EDIT:

It also could be the needle hook distance. If the needle is too far away form the hook tip thread could be shredded. There also is a bobbin case opener that needs attention if not properly adjusted thread could hang on it and break. Or in worst case a combination of all this.

Can you post a short video with open bobbin cover while sewing (slow hand cranking if possible) and the thread shredding happens? Maybe we can see something...

Edited July 3, 2019 by Constabulary

[toxo]

I'll address the closer to the needle/needle bar thing for sure but I seem to have bigger problems.

As the guy with the Consew is experiencing, there seems to be a problem with the space between the bobbin carrier and the needle plate. As you know Folker, originally there was a one piece singer hook which I replaced with a two piece Duerkopp hook. Firstly I decided to leave out the needle guard because it was making the problem above even worse. Secondly the Duerkopp hook can be installed two ways with 180 degrees between the two. I installed it and timed accordingly but was never sure if it was the right way round. Today I took the hook out and turned it around,  I also installed the needle guard and faffed around with the timing and the needle bar. Now, apart from the problem of the thread not getting under the needle plate, I can't get the hook close enough to the scarf to  pick up the thread. It seems as if something has moved on the feed dog side because I'm right up against it. I will attempt a couple of vids later If I haven't chucked it away

[cdthayer]

11 hours ago, toxo said:

still shredding  thread and skipping stitches

For what it's worth, I've had two machines that experienced a shredded thread at the needle problem.

One is a Consew 225 compound feed machine.  I ordered new left and right toe feet to work zippers, and while one pair worked just great, the other pair ended up with shredded and broken upper thread.  Finally, I discovered that when the Chinese drilled the needle hole in the inner foot of this pair, they never went back to knock the burr off underneath from drilling the needle hole.  There was a piece of slag under the foot in the thread groove that worked kind of like a thread cutter, but not as well.  Once I knocked that piece of burr off, the foot has been working great.

Two was recently with my old 1917 Singer 16-41 Jump-foot machine. Once I started getting shredded upper thread, and got to looking at things, I discovered that the inner foot that had been very close to the thread where it exited the needle had become even closer to the thread from use. The inner foot has a small hole for the needle to pass through, and had began rubbing the thread against the needle plate hole enough to shred the thread bad enough that one strand would break and start a "fuzz-back" in the needle until other strands would break and add to a massive bird-nest above the needle at the last thread guide.  Once I realigned the center foot hole to match the needle plate hole, no more shredding.

CD in Oklahoma

[toxo]

After much trial and tribulation I have it sewing again with no shredding. It is still breaking thread, sometimes under the needle plate but more often at the lower tension disc. Can someone please explain how this disc is supposed to work? There seems to be no uniformity to the breakages, sometimes after an inch, sometimes after about eight inches but never more than that. I have taken a couple of videos but I don't have anything to get them below 1.4MB. What do you guys use?

[mikesc]

Videos..Depends on what your computer is ..try downloading "handbrake" ( freeware ) ..and using it to reduce the video size..
or do what most people do...
Upload it to youtube..and post here the embedded link to the video on youtube..
HTH :)