Matching forward and reverse on Juki lu-563

[MarB]

So I got everything working fine, last thing is matching forward and backward stitch length. I've watched all briliant videos from Uwe. Can't thank enough. 

But when I try to make adjustments on stitch length fwd/bwd, the whole assembly moves. I tried oil, penetrating oil, heat, cold and even tapy, tap, tap technique. It wont move a bit. After having a good look, I noticed pin in "feed changing fork asm.". The pin is in the part list (page 11. "reverse feed control lever components" ref. no. 60). It seems that it holds it on the position. Which is weird, if it is meant to be adjusted. Should I get it out? Or should I put more force to the hammer?

 

[Pintodeluxe]

I would adjust the topside mechanism first.  Try adjusting the stops on the right side of the machine to set reverse lever travel.  

Knocking the pin out would be a last resort.  Definitely don't use brute force with a hammer.  That's just a game to see which part breaks first, 

and nobody wins that game.  

[Uwe]

I used to have a pop-up note on that video talking about that pin. YouTube no longer displays the old pop-up notes. The note basically said that if you have the pin, skip this step - it’s not adjustable.

Removing that roll pin is either easy or near impossible.  If the hole is drilled all the way through you can use a suitable roll pin punch tool and hammer to tap the pin all way through and out the other side (if there’s enough room on the other side). Here’s a picture of roll pin punch tools:

 

Here’s how they’re used:

If the hole is not drilled all the way through, your only real option may be to use a drill and drill out the pin. Not sure that will really work, though. 

There’s a very good chance your machine was set up properly at the factory and that the pin is maintaining a good setting. There are a few other factors that might affect stitch length balance. I’d check feed lifting motion and timing before I messed with this pin.

As @Pintodeluxe said, you can always use the external travel limiters for the reverse lever to dial in perfect stitch balance - for one particular stich length. All you have to do is shorten the longer direction of the two stitch directions to match the shorter one.

Designing machines to have matching reverse in all stitch lengths was not really a priority for most vintage industrial machines, because they were often used at one single stich length for the entire life of the machine. If a high volume product required operations at three different stitch lengths, they would set up three machines, one for each operation. Very often the operator in a factory was not allowed to change the stitch length. A mechanic would come and change the stitch length if needed. There was more design effort put into preventing the operator from changing settings than into making it convenient for them to change settings.

 

 

 

Edited April 20, 2021 by Uwe

[MarB]

The difference is quite big. Like 9 mm forward and 3 backward (not precise numbers). The hole is all the way through. But access is hard and it is moving a lot. 

I'll make sure everything is adjusted correctly, but I did that few times allready. It stitches nicely and sounds good. So I'll adjust travel limiters and if longer stitch will be needed, I can always lift the foot and move material. I'm happy it works and don't want to mess things up. For now at least.

Thanks for explaination. I was doubting myself if I had a correct screw.