Timing on my Durkopp 239-125

[toxo]

I mentioned this briefly some  time ago. Since then I'm gradually improving the situation but I can't help feeling that there's something fundamentally wrong with the timing. When I finish sewing with needle up I can't pull the work through without jockeying around with the handwheel. It's always been like this but after installing a servo motor and needle positioner I thought things might improve but no. I can't pull the work through without turning the wheel away from me and dropping the take up arm down to about half way. I've tried changing where it stops with the ENP but it won't let me. Where the needle does stop is about 3/8ths below it's upper limit. I've tried reprogramming the upper limit to the top and turning the motor on/off but as soon as I switch on agains guys? the needle drops down 3/8ths. I should make clear that with the needle up I can obviously pull the work away a little but the thread won't budge until I turn the handwheel. It' a Jack motor. Maybe There's a knack to it? Any thoughts guys?

[dikman]

I generally have to jiggle the handwheel back and forth a little to release the bobbin thread when I've finished sewing.

[toxo]

1 hour ago, dikman said:

I generally have to jiggle the handwheel back and forth a little to release the bobbin thread when I've finished sewing.

On every you tube vid I've seen they nonchalantly lift the needle and pull the work away and what's more they can then put some more work under and start sewing again. With mine if I did that without pulling more thread through (which I quite often forget to do) it would pull the thread out of the needle. Really frustrating. It's a lovely machine but I don't have the knowledge to get it right and I think I'm coming to the end of it now. I know anything else I get will only be as good but it's consistency I need. It's bad enough learning all this stuff without faffing around with the machine all the time. If there was a good mechanic near me I'd gladly pay him but the two nearest me have both had it and said they couldn't get it working which I did  myself with the help of you guys.

Forgot to mention, it's not the bobbin thread it's the top thread.

Edited December 26, 2019 by toxo

[Constabulary]

Is it probably because you have no proper top tension release? When you have fully lift the foot lift lever and the thread take up lever is in upper position check if the two tension discs are free or if they are still under pressure of the spring.

[nylonRigging]

4 hours ago, toxo said:

On every you tube vid I've seen they nonchalantly lift the needle and pull the work away and what's more they can then put some more work under and start sewing again. With mine if I did that without pulling more thread through (which I quite often forget to do) it would pull the thread out of the needle. Really frustrating. It's a lovely machine but I don't have the knowledge to get it right and I think I'm coming to the end of it now. I know anything else I get will only be as good but it's consistency I need. It's bad enough learning all this stuff without faffing around with the machine all the time. If there was a good mechanic near me I'd gladly pay him but the two nearest me have both had it and said they couldn't get it working which I did  myself with the help of you guys.

Forgot to mention, it's not the bobbin thread it's the top thread.

-edit add : ... Constabulary beat me to it, minute ahead of me on posting . .

This is probably something easy simple fix that you just not seeing . you just over thinking it .
Your saying primarily it's ( top Thread ) not wanting to just easy pull out . If the thread not pulling smoothly out of the needle thread when you release thread tension . Then the machine's not fully releasing tension fully . Can you visually see the tension assembly disks go limp when you fully push knee-lift all the way up ?

When stopping to pull work out from under foot and needle . are you using the knee-lift for lifting the needle and tension release ? . Or just using manual lever ?

 Every sew machine I have, when I want to pull material away from under the needle . knee-lift is topped-out to fully push (push pin) that behind tension assembly, letting the tension assembly totally let loose .
( Your needle position ) . Needle has to be stopped on it's down-stroke after just moving past/threw from it's top center. For the thread to pull-out smoothly from Bobbin assembly, and when the tension is fully released on top thread . Material should all pull away freely from under foot and away from needle .
.

Edited December 26, 2019 by nylonRigging

[Constabulary]

so maybe these two drawings help you to understand how the tension release works - it´s from a Singer based machine bit the 239 has very similar parts

#19 (Dwg. 1) is the tension release slide (If I recall correctly you replaced it once, don´t you?). When you lift the foot lift lever it pushes against #20 (Dwg. II - this pin goes back to front through the machine head) and this pin is pushing against #17 which is pushing against the small pin # 11 (which is inside the threaded stud) and this small pin is finally releasing the tension when it is pushing against the disc #13.

So I guess for what ever reason the tension release #19 slide is (probably) too low and does not reach pin #20. Or the small pin #11 is too short and does not reach the center bar of the dics #13. Or - the center bar on the disc #13 is missing or worn. You probably can slightly adjust the center bar on disc #13 (gently hammering it toward the small pin) or you DIY a new small pin from a bicycle spoke or a drill bit or what ever you have. Maybe just 0.5 mm - 1mm are missing - that's already enough for not heaving a tension release. All a guess w/o sitting in front of your machine.

EDIT:

or - loosen screw #22 and push the whole tension unit toward the machine body and then tighten #22 again (of course) - maybe it helps .

Edited December 26, 2019 by Constabulary

[toxo]

Thanks guys. Logic had already told me that was the problem but didn't think of just replacing the pin. You're right Folker, I did replace the tension unit and I vaguely remember that pin not being right. My mind was playing with why the cycle wasn't stopping in the right place. I'll have a look at it later.

I do love playing with it and trying different possibilities. Flat felled seams on upholstery grade leather etc and how close can I get if I grind a presser foot down?

[nylonRigging]

hey, if you don't already know this . one more thing when you get around to dialing-in your tension release, with the lever/pushpin behind tension assembly . if you making a Pin or just cutting down a generic pin to length.
1st natural thing you going to do is make it all super tight ( but don't ) .
You want to have a good amount of knee-lift play before it tops-out with push-pin engagement . and having a ( good amount ) , is having enough play to lift your presser-foot with your needle down and rotate your sewing materials under it, 'without releasing ' the thread tension on the partial foot lift .
.

[toxo]

Thanks guys. Another satisfied customer. Takes slightly more pull than I'd like but I'll take it. Oh what joy I've had this evening. I've almost bonded with it now.  I've used up loads of scrap playing with tension, stitch length different materials and thicknesses. I can even one stitch at a time most of the time although that is hairy even with a 170mm handwheel and a servo motor. I haven't even had to hold the threads at start up most of the time. Now that I can trust it to do what I ask it to do I might even have a go at making something.   (where's the ROFLMAO emoji?)

What suggestions for an adjustable guide that won't cost me an arm and a leg?

[dikman]

I just ordered a drop-down edge guide from Aliexpress, cost me about AU$26 delivered, which I thought was pretty good. I had to make a bracket to fit it to my machine but that was no big deal.

[toxo]

7 hours ago, dikman said:

I just ordered a drop-down edge guide from Aliexpress, cost me about AU$26 delivered, which I thought was pretty good. I had to make a bracket to fit it to my machine but that was no big deal.

That sounds ok dikman. Which one? Always been  concerned about fitting a bracket to the curved underside. Any pics?

[kgg]

What size thread are you using in your machine, every machine has a limited and a sweet size that gives no problems. My Juki loves V92 top and bottom while it doesn't like V138 in the bobbin. I think your machine is rated for synthetic thread Nm 50,70,80,100 or V69 and smaller thread. Going above the rated thread size can cause problems of the top thread getting caught in the hook area as there may not be enough clearance between the larger size needle needed for the larger thread and the hook. May also explain why you have to jiggle the hand wheel a bit sometimes, depends on where the thread, needle and hook are in there cycle.

kgg

[toxo]

41 minutes ago, kgg said:

What size thread are you using in your machine, every machine has a limited and a sweet size that gives no problems. My Juki loves V92 top and bottom while it doesn't like V138 in the bobbin. I think your machine is rated for synthetic thread Nm 50,70,80,100 or V69 and smaller thread. Going above the rated thread size can cause problems of the top thread getting caught in the hook area as there may not be enough clearance between the larger size needle needed for the larger thread and the hook. May also explain why you have to jiggle the hand wheel a bit sometimes, depends on where the thread, needle and hook are in there cycle.

kgg

I was most of the way through a comprehensive answer to this and then it disappeared. I try again later.

[dikman]

Toxo, I just searched through Aliexpress until I found one that was reasonably priced (quite a bit of variation). They call them a suspended guide, by the way. There are two types, one is the "usual" fairly solid looking unit and the other is a cheaper flat steel type. As for the bracket, my CB4500 has two vertical mounting holes at the rear of the head so I simply made an L-shaped bracket to convert the vertical mounting to horizontal holes.

[toxo]

1 hour ago, dikman said:

Toxo, I just searched through Aliexpress until I found one that was reasonably priced (quite a bit of variation). They call them a suspended guide, by the way. There are two types, one is the "usual" fairly solid looking unit and the other is a cheaper flat steel type. As for the bracket, my CB4500 has two vertical mounting holes at the rear of the head so I simply made an L-shaped bracket to convert the vertical mounting to horizontal holes.

Thanks dikman. There's a decent looking one on ebay for around £16 that requires two holes where I have none so will have to drill and tap em.

[dikman]

Yeah, that's what quite a few do. Guess I'm lucky as being a new machine I don't want to be drilling holes in it (yet). I have no idea what the holes are there for but are very convenient.