Juki 1541s timing issue

[JdNelson]

I broke some needles yesterday and had to check the timing on my 1541s. The manual says that the hook to needle position should place the hook at the needle with the needle bar 2.1 mm up from the bottom dead center. My hook is at the needle at bottom dead center and about 3/4 of an inch past the needle when I raise the needle bar the recommended 2.1mm. Also there are some instructions about loosening up set screws on the hook driver shaft and turning the wheel by hand to align the hook. I don't understand that part but if anyone knows I would appreciate clarification. I have used this machine in my shop for almost a year trouble free so threading the machine isn't an issue.

[Wizcrafts]

Are you sure its the hook that moved and not the needle bar? SOP is when the needle has risen 3/32 inch the hook should intersect it about 1/16 inch above the eye. If the impact that broke the needle also push the bar up, you can never get it in time until you lower the needle bar to where it belongs.

 

[JdNelson]

I will see of I can get it by lowering the needle bar, I had it set to 56.55mm, a measurement I found in the online manual. The manual that came with my machine doesn't specify a needle bar setting.

[Wizcrafts]

3 hours ago, JdNelson said:

I will see of I can get it by lowering the needle bar, I had it set to 56.55mm, a measurement I found in the online manual. The manual that came with my machine doesn't specify a needle bar setting.

You will be able to guesstimate how far the bar can be lowered by raising the feet with the hand lifter and handwheeling the machine. If the needle bar doesn't make contact with the feet, it can be lowered until it just misses the fully raised feet. If the manual states the distance, go with that measurement. Making sure you are using the correct needle system, install a new needle and fully seat it and check the timing. If the hook timing is still out, adjust the hook to intersect about 1/16" above the eye of the needle after it has risen 3/32" above BDC.

[JdNelson]

this is the part i don't understand

[JdNelson]

[JdNelson]

I can adjust the hook to needle distance with the screws on the hook but I suspect these instructions would let me rotate the hook backwards so I could time it to the specs,

[Wizcrafts]

4 hours ago, JdNelson said:

I can adjust the hook to needle distance with the screws on the hook but I suspect these instructions would let me rotate the hook backwards so I could time it to the specs,

Yes.

[Wyowally]

As Wiz suggested, I find broken needles  and needle bar movement go hand-in-hand.  I even think some manufacturers made the needle bar setscrew a little on the wimpy side on purpose. Sort of like a shear pin protecting a heavy mechanical mechanism does. If the screw can't hang on when enough force hits the needle to break it, all the better.  Re-setting timing is so basic that anyone involved in their own maintenance need to pick it up. IMHO like Wiz says. BTW, I discovered only a couple days ago the wisdom of another Wiz tidbit. I'd been fooling around with the total presser feet lift, trying to adjust so they'd both lift the same and raise pretty high. I was successful to the point of having the bottom of the needle bar strike one of the feet when they were manually raised all the way. Didn't realize it until I powered up - it moved my needle bar quite handlily!

Edited November 7, 2021 by Wyowally

[JdNelson]

I wasn't sure if the drawing was referring to the set screws on the hook driver shaft or actually the larger lower gear which has bigger hex screws than the upper shaft. I haven't been able to find any videos online. Kind of worried about throwing off the timing of the rest of the machine.

[JdNelson]

48 minutes ago, Wyowally said:

As Wiz suggested, I find broken needles  and needle bar movement go hand-in-hand.  I even think some manufacturers made the needle bar setscrew a little on the wimpy side on purpose. Sort of like a shear pin protecting a heavy mechanical mechanism does. If the screw can't hang on when enough force hits the needle to break it, all the better.  Re-setting timing is so basic that anyone involved in their own maintenance need to pick it up. IMHO like Wiz says. BTW, I discovered only a couple days ago the wisdom of another Wiz tidbit. I'd been fooling around with the total presser feet lift, trying to adjust so they'd both lift the same and raise pretty high. I was successful to the point of having the bottom of the needle bar strike one of the feet when they were manually raised all the way. Didn't realize it until I powered up - it moved my needle bar quite handlily!

I see you are a long distance from the nearest repair guy too. It's just as well to learn how to do it yourself anyway I suppose. I do have a backup but it doesn't produce as nice work as the Juki.

[Wizcrafts]

4 hours ago, Wyowally said:

the wisdom of another Wiz tidbit

We could probably shorten that clunky phrase to just Wizbit ! ;-) LULZ

[JdNelson]

I did get it fixed, it's running like new again. In case anyone else has the same problem and finds this post the procedure is: If you set your needle bar to the factory spec of 56.55mm to the bottom then raise it up 2mm and the hook is not at the needle but elsewhere you need to flip the machine up and drop the oil pan and find the two hex screws on the lower shaft to the right of the big gear and using the hand wheel take note of the screw positions and loosen the one you can't get to first then reposition the needle bar and loosen the other, about 1/4 turn should do it, then set the machine back down and rotate the hook to the factory mandated position then flip it back up and without moving the shaft retighten the screws. 

[Wyowally]

Congrats on your initiative to get 'er done, Jd!  Yep that's the sort of thing I do out here in nowhereland.  And yep, Wizbit sounds great to me Wiz. Jd, I've found it useful, when I remember, to mark screw and gear positions in relation to shafts and other gears. When I remember being the key phrase.