Please TRY the solution BEFORE giving your considered rating.
Ensure that all is clean and free of lint and jams, this is the most likely cause....now for tension troubleshooting .......
solution is for tension problems...if you cannot form any sort of
stitch, the issue is quite different, so please let me know if you need
a different problem solved.....
It is quite long, but just work through each section in order.
"knotting up" can reveal a lot. If you have loose threads on one side
or the other, the tension on the opposite side will be the culprit.
QUICK SUMMARY FIRST:
Ensure sharp new needle,
Thread guides and Bobbin are Clean & Clear of lint
Set Top Tesion to 4 ....then....
Balance Bobbin to suit.
TOP THREAD TENSION:
the looping threads are on the underside as you sew, it is the top
tension. Top tension ought to be between 4 & 6 (this variation to
allow for the different weights of fabric in your
IS YOUR NEEDLE SHARP ?
If you are using a needle that has seen quite a deal of work, or you suspect it may be blunt, change it for a new one !
TOP TENSION & GUIDES:
sure that when you thread the machine the presser foot is up so the
thread goes between the discs and not to one side, top tension between
4 and 6, and that you have threaded through all the guides, including
the last one, usually on the needle arm, just above the needle clamp.
may be there is lint trapped between the discs, this will keep them
slightly apart and reduce the actual tension, sometimes dramatically.
tensions appear correct, and the thread is definitely in the channel
between the discs, but still too loose and looping, try raising presser
foot and remove your thread.
Now, with a 2" (50mm) wide strip
piece of fabric 8 - 10" (20 - 25cm) moistened with methylated or
denatured spirit, gently insert the fabric strip and clean between the
a see saw / to and fro action.
In the worst
cases, gentle use of a needle to pick & remove the jam may be
necessary, but be very gentle and make sure the tension is set at Zero
and the presser foot is raised, (to
disengage tension plates).... do not gouge or score the plates, they need a polished surface to work correctly.
less common, but if the loose threads are on the top, it is bobbin
tension that is loose, it too may have lint in the spring and be giving
a "false" tension.
I would not recommend fiddling with bobbin
tension without good reason, it may end up with missing small screws
and spring pieces, however, you can take the needle plate off to clean
the hook race area (where bobbin case sits)
...this is just good housekeeping, my wife does this every time she replaces the bobbin....
take it out and clean the bobbin case and the fixed metal hook race
with a small brush to remove lint. If there is a significant amount of
lint, use a vacuum and small brush to get the worst.
all this area with a cloth or cotton bud (Q tip) moistened (not soaked)
with methylated spirit, especially if there appears to be fine dirty
deposits....oil and lint combine to conspire against you.
seems likely that you ......really ....do .....actually .....need
.....to adjust the bobbin case, first check there is no lint trapped in
the metal spring where the thread is tensioned.
Drop-in Bobbin case will look similar to this image with the tension screw in the middle of the metalwork....
...the other screw at one end is holding it all together, so
beware....it is not a tragedy to undo the whole lot and clean it, but
very gingerly and lay the bits out in sequence and orientation, or you
risk tearing your hair out !
....this is a
bobbin case from a front loading machine and works in a very similar
fashion to the top loader with drop in bobbin, again, if you dismantle
it, take care so you can put it all
GETTING THE BALANCE RIGHT:
you are certain there's no trapped lint in top tension or bobbin, set
the top tension to 4 and the bobbin tension to a point where you just
begin to feel resistance.
Try using good quality thread of contrasting colours so you can more easily spot the changes.
your zigzag to one width less than maximum (eg. 5 of 6 ...or... 4 of 5
etc) and sew a sample for a few inches and check the result.... adjust
the bobbin tension screw very little at
a time, perhaps 1/16 of a turn.
may find you are playing with this balance for some little while and if
you are putting the needleplate on and off each time begin to think it
cannot be correct to do this.....BUT....it is,
and eventually, you
do get a "feel" for the correct tension and then it happens quite
quickly.....as a user you won't be doing it very often unless there is
lint built up (or are there small hands at work around the house !?!?!)
you live near the ocean as we do, salt air can play havoc with
metalwork inside and out, so to help minimise this, keep a few small
packets of dessicant (silica gel) in your machine
case....no case ? then make some sort of cover !
Same applies in any damp or humid environment, keep your machine dry and dust free.
for a proper full service every couple of years (more often if heavily
used) and if you don't use your machine for a few years, be aware that
old oil will dry out and combining with
dust and form a "clag" like glue (another reason for some sort of cover, even a teatowel !)
FINALLY, A WORD ON THREAD:
it is worth spending the time, energy and money on making something
that you would like to give lasting enjoyment......use quality thread,
.......it may seem to cost a little more at the
time, but the
results, ease of use and added longevity will be worth the extra, and
as a bonus, your tension troubles may be fewer and further between,
because there is a more consistent diameter with good thread, and less
compensating to be done by your tension plates and less thread breaks !