Juki 563 thread loose

[keithski122]

Hi. I'm hoping someone can help me with this problem.The machine is a juki 563 with a servo needle postion motor, the postion is set so that the needle stops just after it has gone past the bottom postion and is rising, heel/tap pedal(I forget which) and the needle rises to the top.Its used daily for auto upholstery and stitches ok.Recently I've noticed that when I stop sewing the thread is loose and twists towards the right hand side of the machine occasionally the thread with catch around the knurled knob, when sewing its fine.I've adjusted the take up spring but should I adjust some more? Thread is ipcabond 20 (138 american?).

[Wizcrafts]

Adjust the bottom stop bracket under the check spring for more travel downward. The adjust the position of the check disks to reduce the slack to the minimum needed to go around the bobbin case and shuttle without making a snapping sound. This adjustment is done by loosening the little screw in the slot and moving the disks one way or the other. Finally, the tension of the check spring is adjusted by loosening a screw in the body that holds the shaft that the spring is mounted upon. With the screw loose, turn the shaft anti-clockwise to strengthen, or clockwise to lighten the spring action. Then tighten the screw to hold that spring action.

[keithski122]

Thank you, will try this tomorrow.Should there be tension on the thread at all times or is there slack at any point? I checked against another of our machines and that also seemed to have slack on it.

[Wizcrafts]

5 hours ago, keithski122 said:

Thank you, will try this tomorrow.Should there be tension on the thread at all times or is there slack at any point? I checked against another of our machines and that also seemed to have slack on it.

The thread should be taut until the needle meets the top of the fabric. From there it depends on the material. I usually keep the thread taut until pickoff time.

[Gregg From Keystone Sewing]

See attached for instructions on how to adjust the thread take up spring.  Many books tell us how to adjust, but not may tell what to adjust it to.  

[keithski122]

Many thanks to you both. Today I firstly adjusted the bottom stop bracket which brought the thread further to the right so reset back to where it began.Then adjusted the check discs from fully anti clockwise to fully clockwise which brought the thread to the left.It seems to work a lot better now.