Juki Lu-563 Backstitching noise

[Doxnet]

Hello all!

I have done the timing on my 1976 Juki Lu-563. I have done it using the superb videos of @Uwe . Thank you some much! It help me a lot!

The machine is sewing good forward.

Except when I back stitch it make a noise from the knot forming under the fabric. I think the hook is past the needle when I push the back lever.

- Hook is close to needle

- From BDC needle rise of 3/32 and needle is at hook (good timing for forward stitch)

-Hook is 1/16 of needle eye when the needle have rise 3/32 up from BDC

Here is a video when I backstitch: https://youtu.be/tAf3HVdkkag

Front view of needle with 3/32 rise from BDC : https://drive.google.com/file/d/1hUuxXIYeRTKdtTcwQqc8uCohTZjKeC9V/view?usp=sharing

Side view of needle with 3/32 rise from BDC : https://drive.google.com/file/d/1hUeaJa8dsoFVWneN7hK4vT5rxrOzMio8/view?usp=sharing

Here a video of hook rotation : https://youtu.be/Gq-6kGUqt5E

Here when I push backstitch lever at 3/32 rise from BDC : https://youtu.be/zuRPbTu486Q

 

Can someone help me solve this problem please?

 

 

Edited March 6, 2021 by Doxnet

[Uwe]

I’m not sure where you got that 3/16” needle rise figure from, but it’s not correct. The Juki LU-563 manual states 3/32” needle rise from BDC for hook timing. Timing your machine using the correct needle rise figure will likely make reverse work properly, along with everything else. 

Those videos don’t really play in my browser and downloading them individually is kind of a pain. YouTube is the place to share videos.

Here’s the relevant page from the Juki LU-563 manual:

 

Edited March 6, 2021 by Uwe

[Doxnet]

@Uwe I have edit the previous post.

I have use 3/32 measurment but written 3/16. My bad.

Not use to post on YouTube.

Thanks for helping me

Edited March 6, 2021 by Doxnet

[DonInReno]

The upper and lower thread is very close to setting the stitch when the noise happens so that narrows it down.   The upper thread is jumping at the sound as the stitch is pulled tight, but bobbin thread doesn’t seem to jump at all....and only in reverse....hmmm
 

You might look under the feed dog for a wear groove that might not normally pinch the thread except from the slightly different thread angle it gets in reverse.   If there is a groove made by a smaller diameter thread it can grab the thicker thread and release it in a jerky fashion like that.   Maybe the bobbin case is pinching the thread and it just doesn’t look tight and jumpy in the video.   Turning the machine by hand as it makes a stitch you could feel what the tension on the bobbin thread is doing with the tip of a small screwdriver.   If it’s real tight and jerks then the pinch is on the bobbin side - if bobbin thread stays rather loose then the pinch is more likely in the feed dog.  If it were on the bobbin side it would do it forward or reverse, no?

I look forward to hearing what it turns out to be!

[Doxnet]

Thanks for helping me ! Really appreciated.

I have a raised troat plate and feed dog for 3 weeks now. I use my juki for binding and sewing. The noise might come from that part. I have reinstall the original troat plate and feed dog and record a video sewing forward and backward.

The binding feed dog from up:

https://drive.google.com/file/d/1hlB36uA_x70hO58DDZrT1DXKp71RNRli/view?usp=drivesdk

Feed dog from down : 

https://drive.google.com/file/d/1hpbkqCQeLNY-1_5URTYq7ZK-hmAN4oxk/view?usp=drivesdk

The binding troat plate and feed dog :

https://drive.google.com/file/d/1hfLqCGLj-zTgJYsoW5qaBZKPC6RwhGUF/view?usp=drivesdk

The original part: 

https://drive.google.com/file/d/1hhi14UWX1nsBkdxjLzbujoXpEoDHQP2E/view?usp=drivesdk

And last, the video :

 

 

 

 

 

 

 

[Doxnet]

Thanks for helping me. Unfortunatly I have not resolve the problem. A technician is going to tune the machine for me by the end of the week.