Juki-LU563 lower bobbin double feeding?

[UpState]

Made my first motorcycle seat today..I give it a 3 out of 10 :D

Anyway, made it through about 95% of the sewing when the bottom bobbin started acting up. The top stitch looks great, it's when I try to pull the work away from the walking foot. The top thread pulls away normally, the bottom of the material has a mess of thread and a loop going back down into the lower bobbin area.  Appears that the lower thread is some how (if this makes sense) is double loading?

I studied the Juki manual for adjustments..but to be honest I can tell that the person that wrote the manual is not a native English speaker...very hard to follow.

Any ideas?

Thanks

[slodat]

Are you holding both thread tails tight when you start stitching? Not doing so could cause what you describe..

[Mike8560]

VeI've had a problem with tention usualy when i switch thread types.

[needles eye]

hi am sure with the seats it grows as it goes
and as you'll be aware the rule of thumb is loose bottom then stitch crank the top tension a bit more, turn the adjuster clockwise
it is suggested to sometimes use a slightly lighter thread wherein the bobbin to obtain a really tight stitch
yep i got taught to hold the threads when i first started sewing as otherwise they get pulled in and double sewn as slodat says
you've checked the bobbin tension by adjusting the appropriate little screw on the holder? note there are 2 screws sometimes, check the manual for the right one, think then it goes righty tighty lefty loosey, try it and see
careful not to lose screw! do it over an old ice cream container, say
bobbin should just start to let thread go when you hold it up in the air
then you'll need to balance top tension up
as mike says generally whenever changing threads
life's a fine balancing act eh
celui qui veut, peut (Fr.), he who has the will has the skill
good luck

[UpState]

Appears that everyone agrees on the tension adjustment which is something I can work with. I'll also give the tension - by pulling on the threads a try also.

Thanks all..

[needles eye]

Hey big fella try this one just found, cheers

http://www.sewconsult.com/sewing_machine_troubleshooting/sewing_machine_troubleshooting.htm#how_do_i_stop_the_thread_from_looping_2

[UpState]

Thanks needle eyes...that site also suggests tension adjustments.

Ed

[needles eye]

Hi Ed
let us know how you go with the threads outcome
i'd like to know, cheers

found if i didn't hold the threads in my left hand when started a new tack that the needle would often then come unthreaded and would get the double sewing up you described, further, you know to pull the threads away when the tension arm is at the top of the stroke as it goes up and down eh, just stating for clarity, you may need to wind the handwheel on towards you to get the arm up the top to release the threads, yep, yep just stating the obvious

my young brother has a nice bike
with a number plate "2 scary"!
it's an evo motor bored out heaps, with monster carbys
with mobs of billet gear, wheels etc
and a chopped frame
pulls like a tractor he reckons
but real scary on cornering 'though
hence the personalized no. plates i guess!
can try and post a pix for you

those bike seats look pretty tricky to do a good job of
like they say
if at first you don't succeed..............

[UpState]

needle eyes

here's the bike, just welded on the hardtail..so I needed a seat. Made the pan, shapped the padding and covered the seat. Wanted to go with French seams..but I started having the thread problem and felt a little (LOT) over my head anyway. The seat could be better, but for the first time ever using an upholstery machine and figuring the patterns..I'm happy with what came out..it works for me!

Ed

[needles eye]

ooh la la
that's friggen' horny

[Mike8560]

I just saw a cool movi e called the fastest Indian a out Bert Monroe from new Zealand set the speed record   Way back when

[UpState]

I just saw a cool movi e called the fastest Indian a out Bert Monroe from new Zealand set the speed record   Way back when

That is a great flick...really enjoyed watching it.

[needles eye]

keep me eyes peeled for that particular  flick, ta

will get some pix for you soon, probably over the weekend
he's getting new handlebars made up
always doing something
changed the pipes half a dozen times this last six months i'm sure
guess that de gustibus non est disputandum (L.), there is no disputing about tastes

meanwhile you may be inclined to check out -
http://en.wikipedia.org/wiki/Lockstitch

since you're mechanically inclined you can now perceive that the bobbin case and hook and holder (which bobbin case sits in) are rather important being for good tension, and, for a standard industrial sewing machine you can source a new bobbin case for around ten bucks and a hook and holder for around thirty five bucks local plus postage, probably cheaper from china
the hook gets burred on the holder and and can cause real dramas, the inner race can get all scoured up and grabby
and the washer spring in the bobbin holder looses its bounce and then plays up, crud and grime sticks to the inner face of the bobbin holder which holds up free spoolin'
moreover lint and bits of old thread and whatever can jam things up a bit too and make a bad scene
apparently you should clean the bottom feed area out daily, maybe with a paintbrush, say
and a drop of light sewing machine oil never hurts about the place
if you endeavour to set the bobbin case tension, remember to hold it up in the air by a thread from the loaded  bobbin being inside and then adjust screw such that merely ruit mole sua (L.), it falls by its own weight
obviously there are other parameters, like setting the thread tension into the bobbin consistently from the tension setter where you load the bobbins up it from the reel via guide spring, further, things can change in the overall tension pix if the thread length starts to creep in sewing operation as and if you adjust the top tension
incidentally don't be afraid to crank the top tension on after setting up the bottom tension, you might want to experiment with a fish scale and note different tensions, say, or put on enough tension as you might expect from pulling in a nice fish
don't let it get away from ya
:'(