Switching to a smaller needle increased the problem… now it’s got a thinner shaft going through a thicker bunch of fabric, and it’s bending. If anything, I’d go up a size.

But most sewing machine problems that can be fixed by a user are covered here:
These are the likely culprits:
–Bad needle
–Dirty
–Misthreaded
–Seams started incorrectly

The 10 minute fix for most of what ails most sewing machines:
– Dig out the manual. Take all the thread out of/off of the
machine. Pull the needleplate and the bobbin case if it’s
removeable. Clean and oil per the manual’s recommendation. Use a
brush and vacuum, not compressed air (which blows lint in
farther), and real sewing machine oil, not 3-in-1 type oil (it
hardens and freezes the machine) nor WD-40 type stuff (it’s a
solvent, not a lubricant).

– Put in a new needle of the correct point style for the fabric
you’re sewing (ballpoint for knits, sharps for wovens) and the
right size for the thickness of fabric (10/70 for shirting weight
fabrics, 12/80 for heavy shirtings or light pantsweight. 14/90
for medium to heavy pantsweight, 16/100 for very heavy fabrics.
Make sure the needle is in right way around — a needle in
backwards will skip stitches or not stitch at all.

– Rethread, with manual in hand. Make sure the presser foot is
UP when you thread the top — it opens the top tension so that
the thread actually gets in between the tension disk (loops on
the bottom, not enough tension on top).

– Fetch up the bobbin thread. You need about a 4" tail of thread
top and bottom. Run both threads under the presser foot and
behind it.

– If you’ve been playing with the top tension, set it to 4. If
you’ve been playing with the bobbin tension, let me know and
we’ll try to rebalance it, but you’re likely to have to take it
into the shop.

Now, each and every time you start to sew a seam, this is how you
do it:
1) Place the fabric under the needle, and use the handwheel to
lower the needle into the fabric (be sure to turn it the right
way… seee the manual).

2) Drop the presser foot.

3) Hold the thread tails behind the presser foot with your left
hand.

4) Take a couple of stitches

5) Drop the thread tails and sew normally.

If this doesn’t fix your problems, you may have some thread
caught farther in the machine than you can spot… doesn’t take
much for some machines to start pitching a fit. Or you may have
accidentally knocked the machine out of time with one of the
jams. Bad timing is actually a fairly rare event, often preceeded
by broken needles and loud noises, but a good solid jam is
another way to throw off the timing. You can check here to see if
you think timing is the problem:
http://sewusa.com/Sewing_Machine_Repair/...
but that’s generally something that a repair shop needs to
adjust.
References :
50 years of sewing

It’s the Singer Featherweight manual….it might have the infor. you’re looking for. I only looked briefly but it seems to have illustrations as well, hope it will be what you need.
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P.S. Find it refreshing – a young lady who has interest in sewing,and can!
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Just a guess. Those old SIngers are good machines. I have one I haven’t used in years. Good luck.
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