Knee lift won't engage on my Juki. Ddl-8700industrial straight stitch

Question edited for correct name of the maker 'judi' to 'Juki'.
Question moved from Office Equipment.

Motor Failure.

https://www.google.com/search?q=juki+5550-6+e7+error

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It is generally because you have not taken your knee completely off the knee lift.
Whenever you use your knee lift, it opens the thread tension and lets out more upper thread.
If you find out you are not leaving your knee on the knee pedal, try to only lift the foot as little as possible when you do your turn. I find out that when I am in a hurry I leave my knee against the knee lift as I am sewing and I have the same problem.
Good Luck. :)

Perhaps a manual would be helpful:

File JUKI DDL 8300N Instruction Manual pdf

You should probably contact the manufacturer with questions. Hopefully, you did some thorough research before purchasing this machine. From the info I found, it appears to be a straight stitch only machine. I don't know anything about this machine, but I would be hesitant to purchase a straight stitch machine for sewing swimwear. Usually, swimwear needs a stretch stitch or zig-zag capability. Just my thoughts...

Amazon com Juki DDL 8700 Industrial Straight Stitch Sewing Machine Arts...

Juki DDL 8300N Industrial Single Needle Lockstitch Sewing Machine with...

JUKI DDL 8300N Straight Stitch Industrial Sewing Machine With Table Lamp...

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Mine does this too sometimes. Lift up the head and look in the middle of the oil pan. The knee controller runs through there. Make sure the black knob is not stuck. Hit the knee thing a couple of times to make sure it is not stuck. It should move freely up and down. That may fix the problem. If not, look st the small post to the left and behind the oil intake. Move the manual presserfoot lever on the machine to see it move. It will be stiff, but it should still lift a little. Usually jigging these two parts will fix the problem. Good luck..

I could not find that error using the Manual that is on the Internet.
I suggest you call or email their Sales and Service in the U.K.

Their email is [email protected]

JUKI DDL 5530 DDL 5550 Parts Needles Service

Does this look like yours?
JUKI DDL 5550N Handbook

set up on quilting table? wheres the oil pan?? if your machine sews fine straight and skips on curves i think you are lifting the presser ft as you make the turn. theres nothing wrong with the machine. you could always change the needle which is always the first thing when you encounter a sewing problem.

Again: JUKI DDL 5550N Manuals

Hi there, no you cannot do a stretch stitch on the ddl-8700. It only has on stitch and it is a straight lockstitch.

Check the tension unit, when you use your knee press a pin should open the tension discs then return to normal, check for any fluff in the discs as well