Juki Lu563 bobbin case clacking sounds?

[Nate88]

Hello amazing leather workers and sewists! 

I need some help figuring out what going on with my beloved Juki. I'm 2/3 finished reupholstering a sofa and I started having issues with top thread getting stuck outside around the bobbin case. Thought it was just thread tension issue, but then this clacking / grinding sounds developed. 

I oil everything regularly and also oil around the bobbin case.

 

I took out the bobbin from the bobbin case to look for jammed threads....nothing there it seems to be nice and clean. 

 

When investigating I noticed that the whole bobbin case assembly seems to have a significant amount of play. Like something is loose but I can't figure out what.

 

Any help would be super appreciated. Thanks!

 

[Nate88]

This video might show the sound I'm talking about a little better. 

[Wizcrafts]

If the sound bothers you, back slightly off the pull of the opener arm. It looks like it is pulling the bobbin case hard back to its physical limit (set by the tab that fits into the cutout in the throat plate). That makes a metal on metal sound upon impact. If you move the arm forward a smidgen the case won't hit its motion limit and should quiet down. The opener only needs to move the tab on the case slightly to clear the top thread.

[Nate88]

Thanks Wizcrafts!

 

Just to make sure I'm following you....the purple/yellow circle is the opener arm. That needs to slide forward just a hair. The purple circle is the screw where I could bring the arm forward.

 

 

Edited January 21, 2021 by Nate88

[Nate88]

Do you have any ideas on why the top thread was slipping down along the outside of the bobbin case? All the sewing frustration aside, I was worried that I had messed up my machine. 

The sound does bother me but more importantly I was worried that this sound was related to why the thread kept falling getting caught alongside the bobbin case. 

I only have 1 spool of thread (tex69 and I'm using an 18 needle) so when I loaded a bobbin I would go full speed and max out the revolutions to fill up the bobbin quickly. After doing this like the 3rd time then this loud metal clacking sound developed. 

Edited January 21, 2021 by Nate88

[Wizcrafts]

3 hours ago, Nate88 said:

Thanks Wizcrafts!

 

Just to make sure I'm following you....the purple/yellow circle is the opener arm. That needs to slide forward just a hair. The purple circle is the screw where I could bring the arm forward.

 

 

That is correct. Loosen the purple circled screw, budge the arm forward a tish, then tighten the screw and test to see if that fixed the bobbin case  There should be a smidgen of slack left in the bobbin case when the opener arm reaches it farthest backwards motion.

It is still possible that something else has gone wrong from your running the machine flat out without a load. Flip it over and check the bottom for loose screws on the gears.

[Pintodeluxe]

There's nothing about winding a bobbin that should throw it out of wack.  Just make sure you raise the presser foot as you wind the bobbin.

If thread is getting caught underneath by the bobbin, it's likely that your timing and / or needle bar height are off slightly.  It's pretty easy to knock the needle bar sewing over a thick seam.  If the needle bar screw isn't really snug, it can move upward.  So start by confirming your timing and needle bar height.

Also, a drop of oil down by the bobbin case works wonders on my 563.   

[Nate88]

Okay this is great advice. I did end up adjusting needle bar height a recently so maybe I adjusted it off a tiny tiny bit.

Thanks for the tips!!!