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Troubleshooting breaking needles
There are a couple of possible reasons why
you are breaking needles, So if you can see if you can help me better
understand.
1) Are you sewing Caps or flat goods?
2) Are the needles
breaking at the eye or further up the shaft of the needle?
3) What happened
just before this anomaly occurred? Birdsnest for example...
4) Where is the
weird noise comming from? Behind the needle bars, On the sides, is it a
grinding noise or a squeaking noise. Is the noise comming from the
bobbin area?
5) Are you oiling your rotary hook every 4 hours?
You
may want to check your hook timing, to do so follow these steps and let me know
what you find.
1) Set your machine to needle number 8, by presing the
number 8 on the control panel
2) Remove the needle plate.
3) Power off the
machine.
4) Rotate the main shaft wheel in the back of the machine two whole
rotations then set it to 200 degrees.
5) Your nedle should be all the
way down now, look behind the needle and locate the hook point located somewhere
behind the needle on the rotarhy hook. The hook point will be the tip of what
looks to be an open end of a pair of scissors. The tip should line up right
behind the needle, and the gap between the needle and the hook point should be
about the distance of a slender business card, or .50mm. Push needle 8 backwards
towards the hook point and see if the hook point is resting up against the back
side of that needle, if it is then the rotary hook is breaking the needles, and
you will have to adjust the hook timing.
That rotary hook spins and the
hook point picks up the upper thread and joins it with the bobbin thread, If the
hook point is too close or resting against the back of the needle, then the
rotary hook point is snapping the needle as it makes contact. There needs to be
a gap as I mentioned of about a half a millimeter.
If the rotary hook
point is not aligned directly behind the needle, than slowly turn the wheel in
the back of the machine until it does line up behind the needle, and let me know
what degree the wheel is set to when the hook point does line up directly behind
the needle. Hook timing is optimum at 200 degrees, but it can be set anywhere
from 198 to 202 degrees, depending on how long the eye of the needle is. If your
hook point is lined up behind the needle less than 198 or more than 202 then you
will have to set hook timing.
Also one more thing, just under the needle
plate you will see the trimming components, There is a silver peice and it
slides underneath a black peice that has SWF engraved on it. Look at the silver
knife part, this peice should be almost all the way under the black peice, the
only part that should be sticking out it just a small triangle of the silver
knife.
The silver peice is what swings open and collects the upper
thread and the bobbin thread, then it pushes it under the black peice which does
all the cutting, as I mentioned the only visible part of the silver knife should
be the triangle tip. If you notice that the head of the silver peice is sticking
out more than what I described, than your needle may be striking that component
causing to break.
If you do find that this silver knife is sticking out
more than described, grab a hold of it and swing it out from under the black
peice and see if there is thread jammed up under the black peice causing the
kinfe not to go all the way under the black peice, also look under the black
peice, you will see a very thin peice of metal, this is called the under thread
presser. If it looks like it is bent upwards or sheared part way off, then this
would inhibit the silver knife to close all the way.
To test the
movement of the knife do the following.
1) Turn the machine
on.
2) Turn the head off so that the needle will not go down when we do
a thread trim, we do not want to break any needle if the knife is indeed
sticking out from under the black peice more than it should. To turn off the
head, simply toggle off that switch just above the red light, once the red light
is off then the head is turned off.
3) Do a manual thread trim and watch
the movement of that silver knife, You should see it open and then go back under
the black peice, and as I mentioned the only bit that should be sticking out of
the black peice when the knife finsihes its motion, is the small triangle at the
rear of the head of the silver knife.
If it is sticking out look for
what may be causing it to not go all the way under as described
above.
Allen Gripton
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